Lapua lot testing and barrel wear question

[Gleedus]

If you only have 100 yards then testing and picking the lowest SD is best yes.

My results agree with you on the ES vs group vertical spread. I can see the group form through my scope. The high velocity and low velocity do not mean they will hit high in the group or low. Ive had a 1070fps and a 1030 land within 1/2" and then the next 1070 was 6" lower. There is more going on then just velocity.
Maybe I should record and plot each shot but I cant see any useful info being gained.

Now I do have a box of ammo that I weight and recorded weight, length, rim thickness. I plan on plotting that box POI on a paper at 200. Might be pointless then again who knows.


I shoot in the open and seldom see wind less then 5 mpr typically 5-8 is a calm day. Ive shot groups at 200 in 2-3 mpr and 10-12 mpr and vertically they are the same. Horizontal depends alot on how consistent the wind is and how alert I am of course. I have it set up that I typically shoot with a 8-10 o'clock wind and I don't test with head or tail wind.

 

[IdealJoe]

You have to remember many of us absolutely dont know this stuff and are learning. The reasearch I did looked like a air gauge would work. Up until now we only got told how stupid we are it wont work. Nobody said WHY it wont work.
Finally after a bunch of name calling someone (you) says it wont work because of the rifling. Bingo makes perfect sense the additional clearance would make the resolution very poor not to mention any rifling variations. The problem is that we are all told how stupid we are so are now sceptical of your side of the discussion and will have to research some more...
Stay calm dont get to yelling around and stay in the discussion we may learn something. Over here. I for one appreciate you chiming in.

Thanks for the perspective. It's sometimes hard to filter out the noise.

There are air gauges that will work. Just not the ones linked.

The limitation with air gages in rifle bores had to do with custom shape tools needed to be made to account for the rifling, then, the air gage would show a change in airflow indicating a larger or smaller condition but not providing more information as to where or what was causing it. In the end, it couldn't provide meaningful data. If the thought was to measure wear in the throat area, as it appears Justin is pointing to visually, I just don't see air working.

I have decided against air guaging.
When I win the lottery, this is what I will use to measure barrel wear.
I use cadd (computer assisted design drafting)
laser scanning large areas to create 3D models to earn a living,
so lidar point fields I can work with.

Automated barrel inspection and 3D measurement - Novacam

www.novacam.com

Thanks for the link. That is some interesting equipment! I own an optical CNC coordinate measuring machine that uses very similar technology. Just not on internal features. It measures depths using the focus of the camera system. It works well but the accuracy of measurements has its limitations. I looked for accuracy specs on the Novacam machine. As with mine, they state "repeatability" accuracy in the millionths of an inch but do not state a true accuracy. I'm sure that is because it's a variable and very complicated. I'm sure a super useful tool nonetheless.

There are numerous other systems that accomplish this as well. However not the particulate, flaws or finish evaluation. Those evaluations may be accomplished with different tests. Yes they are pricey. People just have to open their eyes and minds. They just do not wish to spend the time and effort it takes to learn.

Do these numerous other systems have a name? Got a link? What are these different tests? What is considered pricey? You speak in absolutes but with absolutely no detail. To me, that makes you sound like a bag of wind rather than someone with actual knowledge on the subject.

 

[AGrizz]

Thanks for the perspective. It's sometimes hard to filter out the noise.

The limitation with air gages in rifle bores had to do with custom shape tools needed to be made to account for the rifling, then, the air gage would show a change in airflow indicating a larger or smaller condition but not providing more information as to where or what was causing it. In the end, it couldn't provide meaningful data. If the thought was to measure wear in the throat area, as it appears Justin is pointing to visually, I just don't see air working.

Thanks for the link. That is some interesting equipment! I own an optical CNC coordinate measuring machine that uses very similar technology. Just not on internal features. It measures depths using the focus of the camera system. It works well but the accuracy of measurements has its limitations. I looked for accuracy specs on the Novacam machine. As with mine, they state "repeatability" accuracy in the millionths of an inch but do not state a true accuracy. I'm sure that is because it's a variable and very complicated. I'm sure a super useful tool nonetheless.

Do these numerous other systems have a name? Got a link? What are these different tests? What is considered pricey? You speak in absolutes but with absolutely no detail. To me, that makes you sound like a bag of wind rather than someone with actual knowledge on the subject.

These are just a few things that should help the individuals that still do not understand. If the point is not made at this time then you must look somewhere else. There are more variable pieces of equipment that serve the same purpose from a very large group of manufacturers. Those you will have to find for yourself. That is what computers are for present day. Help yourself.

https://willrich.com/product/gun-barrel-diameter-gages/

https://willrich.com/product/dyer-gun-barrel-gage/

https://www.nides.cz/en/agi/ Not for .22lr however the same principle

https://mcgowenbarrel.com/bore-groove/ This may be of interest to some. Subtract the bore diameter from the groove diameter and then divide that in half. You will then have your rifling depth for one side. IE. 17 caliber barrel, Groove .172, minus Bore .168, equals .004 divided in half because there are 2 sides to this dimension of .004 and we have a rifling depth on one side of .002. About 1/3 the thickness of a sheet of paper.

https://www.productionmachining.com/articles/honing-system-eliminates-a-gun-barrel-lapping-operation Honing and measuring the barrel profiles are included in one operation here.

https://www.productionmachining.com/zones/measurement These are measuring devices that are able to go to a depth in a cylinder or “Barrel if you will” and measure the interior diameter with a probe. This type of tooling has been available for over 50 years.

 

[AGrizz]

Caliper???? How many errors can one human make??? How many guys here have actually slugged a barrel, the proper way, with a micrometer, using a proper slug to avoid errors[ you cannot use anything], also making sure while using the several slugs needed, you periodically reverse them or bump them up to check, and then make sure you finish my checking for a round bore at the muzzle ? Report back if/when you get proper slugs to measure and do 10-15 of them. You know what to look for on the slug, other than measurements right ? Oh, you got the barrel clean, right down to bare metal right? Properly lubricated it, lightly, right?
And FYI you can look at all the videos you want, as I said, air gauges are typically used to see interior variances, primarily during lapping.
Barrel interiors are established after drilling and/or reaming and usually checked with deltronic pins. You want to check barrels, buy a set from .2150" to about .222", make sure you get them in 1/2 tenths, prepare to spend well over $1000.

C.C. guy with the pie chart.

Tim, Tim, it is very evident you have absolutely ZERO experience in an inspection laboratory or machining or being a Tool and Die Maker. So why dont you just go and curl up in the corner and keep your mouth shut.

Where you may be of some use is in your ability to shoot a rifle. Advise you try to stay on that course and leave the rest to people who know. Using a Deltonic Pin in a barrel is like sticking your dick in old Haggie from the east side.

You are trying to be something you are absolutely not and that is the rimfire genius God of all you surveil.

When I said this it was 100% accurate. Now to go wash the stench off.

 

[IdealJoe]

LOL Grizz. Nevermind. You've never measured a rifle bore. You don't know what you don't know... But some of us do.

 

[1813Benny]

It was previously noted that almost no top flight shooters post information in the rimfire section on SH.....and this thread it is a prime example as to why they do not.

...keep the comments coming.

 

[phlegethon]

It was previously noted that almost no top flight shooters post information in the rimfire section on SH.....and this thread it is a prime example as to why they do not.

...keep the comments coming.

If Tim is any indication, I will shed a single tear for the loss to this community.

 

[justin amateur]

almost no top flight shooters post information in the rimfire section on SH

It requires a thick skin and the ability to take a joke, and criticism, in order to enjoy the 'hide.
Most aren't comfortable with that level of interaction in a public forum.
Lucky for y'all, I'm easily entertained. Plus, I have no fear of failure.
Learn more from my mistakes than I do from my successes.

 

[grauhanen]

If you only have 100 yards then testing and picking the lowest SD is best yes.

Testing ammo at three and four times the distance can be a fool's errand. There's so much that can go wrong -- and does go wrong -- the further out the testing is done. A shooter may never know what went wrong or what combination of factors conspired to produce inconsistent results. Wind? Gravity and ES? Something else that causes inconsistency such as offset center of gravity in the bullet or inconsistent and non-concentric bullet seating?

If .22LR ammo can't perform well at 100, there's absolutely no reason to expect it to perform well at further distances. At 100 it's possible to determine what shoots very well. This ammo doesn't self-correct to produce better results the further it goes, it just gets worse.

 

[Gleedus]

It was previously noted that almost no top flight shooters post information in the rimfire section on SH.....and this thread it is a prime example as to why they do not.

...keep the comments coming.

Then post some usefully info so those of us that wish to learn can. Rather then making a comment like your part of some elite group thats to good for us.
If you wanted to join us in field matches most on here would gladly help a guy get started.

What defines top flight shooter? A BR guy sitting at a bench on a rest putting 10 shots in 0.25" at 50? Or maybe its going 10 for 10 on a 6" plate at 200 yds standing supported off of a barricade?

Both of those require different skills and dare I say the first of those is more difficult for the setup and the second of those is more difficult task for the shooter.

Both of those top flight shooters have something to offer the other. Our goals are slightly different therefore so is are our focus.

I probably dont know as much as you but I'm willing to look the fool to learn and win.

 

[Gleedus]

Testing ammo at three and four times the distance can be a fool's errand. There's so much that can go wrong -- and does go wrong -- the further out the testing is done. A shooter may never know what went wrong or what combination of factors conspired to produce inconsistent results. Wind? Gravity and ES? Something else that causes inconsistency such as offset center of gravity in the bullet or inconsistent and non-concentric bullet seating?

If .22LR ammo can't perform well at 100, there's absolutely no reason to expect it to perform well at further distances. At 100 it's possible to determine what shoots very well. This ammo doesn't self-correct to produce better results the further it goes, it just gets worse.

I will fully have to disagree...
Testing ammo at 200 yards is crucial for knowing performance at long range. At our matches we seldom see less then 100 yards. 50 performance means nothing.

At 50 yds my rifle match, center x, contact, force all shoot very simular. Force has the biggest velocity spread and the best groups at 200. If I would go by 50 yard results and velocity alone I would be shooting Center X which is 2x bigger groups at 200.
At 100 yards you just start to be able to see the difference. But a little further is much better.

How many 20 shot groups at 200 needed to give a idea of performance? How consistent would those groups have to be?

If your game is ELR then testing at 3-400 is a good Idea. Maybe try weight sorting ammo and see if you find a difference at 400...

100 yd vs 200 yard is NOT a comparable task.

 

[308pirate]

And FWIW airguages don't measure anything.

Why does anyone listen to someone this ignorant?

 

[1813Benny]

Then post some usefully info so those of us that wish to learn can. Rather then making a comment like your part of some elite group thats to good for us.



I probably dont know as much as you but I'm willing to look the fool to learn and win.

CRPS
I believe that you missed the original intent of my post, specifically that the need for people to sling mud behind the anonymity of the keyboard is a huge turn off to many who would otherwise be willing to contribute their knowledge. This was an observation, which as I noted was also previously mentioned in another thread. My post was an open reminder that it's good for everyone's benefit to keep a reasonable level of decorum.

Nothing more, nothing less.

Take a look at your second sentence - which is an unnecessary assumption. I never consider myself "to [sic] good" for any group of fellow competitors, regardless of discipline, level of education or shooting accomplishments. Aside from 40 consecutive years of smallbore rifle competitive experience, I have mentored new shooters, coached a JR rifle team and currently spend more time promoting and running matches than participating. Not bragging, just giving some factual background.

With that said, do I consider myself "elite"?

Nope.

With regards to my level of knowledge vs other competitors, that is relative to each discussion topic and personal experience. I occasionally contribute my experience and knowledge to worthwhile discussions on this and other forums and will continue to do so for the foreseeable future. I enjoy learning and discussing topics, but I am also happy to gloss over contentions threads.

If I offended anyone by the above or by my prior post, I guess that it is what it is. I have nothing to prove and hold no animosity.

With that, best regards and have an enjoyable day.

Ken

 

[nockhunter]

WOW this spiraled badly

Mike

 

[1813Benny]

...and now back to our regularly scheduled program.......on...uh....what was the topic?

 

[Gleedus]

CRPS
I believe that you missed the original intent of my post, specifically that the need for people to sling mud behind the anonymity of the keyboard is a huge turn off to many who would otherwise be willing to contribute their knowledge. This was an observation, which as I noted was also previously mentioned in another thread. My post was an open reminder that it's good for everyone's benefit to keep a reasonable level of decorum.

Nothing more, nothing less.

Take a look at your second sentence - which is an unnecessary assumption. I never consider myself "to [sic] good" for any group of fellow competitors, regardless of discipline, level of education or shooting accomplishments. Aside from 40 consecutive years of smallbore rifle competitive experience, I have mentored new shooters, coached a JR rifle team and currently spend more time promoting and running matches than participating. Not bragging, just giving some factual background.

With that said, do I consider myself "elite"?

Nope.

With regards to my level of knowledge vs other competitors, that is relative to each discussion topic and personal experience. I occasionally contribute my experience and knowledge to worthwhile discussions on this and other forums and will continue to do so for the foreseeable future. I enjoy learning and discussing topics, but I am also happy to gloss over contentions threads.

If I offended anyone by the above or by my prior post, I guess that it is what it is. I have nothing to prove and hold no animosity.

With that, best regards and have an enjoyable day.

Ken

Were Good Ken. I took no offense to what you said. I replied in such a way to test you. You passed! A lot of guys come on here (from both sides of the discussion) with pointless blabber. So i blabbered a bit too...
If you would have come back yelling.... . I'm in commercial construction so the skin is maybe to thick somedays....

I enjoy these conversations as I am interested in learning new things and both side of the story. I will admit to pushing a side hard to make the "opposition" talk. They talk to the fool and the fool learns things.

As said we are good. In fact I even appreciate Tims contribution. He makes the other side say stuff... and the fool keeps learning what to test next.

 

[Tokay444]

I will fully have to disagree...
Testing ammo at 200 yards is crucial for knowing performance at long range. At our matches we seldom see less then 100 yards. 50 performance means nothing.

At 50 yds my rifle match, center x, contact, force all shoot very simular. Force has the biggest velocity spread and the best groups at 200. If I would go by 50 yard results and velocity alone I would be shooting Center X which is 2x bigger groups at 200.
At 100 yards you just start to be able to see the difference. But a little further is much better.

How many 20 shot groups at 200 needed to give a idea of performance? How consistent would those groups have to be?

If your game is ELR then testing at 3-400 is a good Idea. Maybe try weight sorting ammo and see if you find a difference at 400...

100 yd vs 200 yard is NOT a comparable task.

In a vacuum, ammo that shoots smaller at 50 yards will shoot smaller at 200-300-400. Otherwise, Bryan Litz would be $25,000 lighter by now. Your group size cannot diminish with distance.

 

[Gleedus]

In a vacuum, ammo that shoots smaller at 50 yards will shoot smaller at 200-300-400. Otherwise, Bryan Litz would be $25,000 lighter by now. Your group size cannot diminish with distance.

The groups absolutely will NOT get smaller at 200 then at 50.
Actual testing from my rifle was.

In MOA Center X at 50 yd = 0.9 at 211 yds in MOA 3.6

Eley force at 50 = 1 moa. 211 yds = 1.6 moa

Long range is mostly in the ammo. But just because that ammo is great at 50 does it mean it will be great at long range.

 

[grauhanen]

In a vacuum, ammo that shoots smaller at 50 yards will shoot smaller at 200-300-400. Otherwise, Bryan Litz would be $25,000 lighter by now. Your group size cannot diminish with distance.

The groups absolutely will NOT get smaller at 200 then at 50.
Actual testing from my rifle was.

In MOA Center X at 50 yd = 0.9 at 211 yds in MOA 3.6

Eley force at 50 = 1 moa. 211 yds = 1.6 moa

Long range is mostly in the ammo. But just because that ammo is great at 50 does it mean it will be great at long range.

CRPS, I think you misunderstand. The point is that ammo that shoots better at closer range will ipso facto shoot better further out. An ammo that gives worse results than another at, say, 100 yards can't give better results at two or three or any times the distance. At the risk of being long-winded, I'll elaborate.

The same is true for 50 yards, but at that distance it's often impossible to distinguish easily which ammo gives the better results, especially when the results are based on insufficient sample size and testing is not done in consistent conditions. To illustrate, a rifle and ammo that produces 1 MOA results consistently at 50 is not always easily distinguished from a rifle and ammo that gives .9 MOA results. This difficulty can be particularly amplified by too small a sample size. Many shooters will be familiar with results where ten groups of five shots at 50 yards produce results that vary from .2's, .3's and .4's all on the same target. That doesn't make for the comparison of results in a straightforward way.

This is why I suggested in a previous post that 100 yards was a suitable distance at which to evaluate ammo performance. It's much easier to identify ammo that shoots better than others. With regard to what Tokay444 said, an ammo that gives reliably better results at 100 yards will not be outperformed by ammo that did worse at that distance.

Since .22LR accuracy is non-linear, which is to say that as distance doubles a group's size more than doubles.

To be sure, there are instances that happen rarely when ammo testing at testing facilities such as those of Lapua in Arizona or in Ohio when results with a particular lot in a particular rifle have better results (MOA-wise) at 100 meters than at 50. Since these results are recorded in a tunnel with electronic sensors, there's no paper deflection at play and the results are unaffected by wind.

But these kinds of results are not regular and, more importantly, not predictable. That is to say, they are the result of unexpected circumstances. It's not possible to test for ammo that will reliably give these results. One of the reasons that may explain them is that the ammo has center of gravity offsets that cause unusual and ordinarily unexpected results. It's not possible to test for an ammo's center of gravity -- at least not without destroying it.

On average, results examined from ammo testing in testing facilities, where it's possible to acquire reliable data for results at two distances in a test tunnel, show that on average group size increases by a factor of 2.8 between 50 meters and 100. Some rifle/ammo combinations will see the factor be smaller, others will experience an even larger increase. The thing is that this is not predictable. What should be expected is that results will more than double as distance doubles.

And the further the distance, the greater the factor. In other words, if the average is 2.8 between 50 and 100, it will be higher (on average) between 100 and 200 and higher still between 200 and 400.

With regard to Litz, in late 2014-early 2015 Bryan Litz issued his "shoot thru" challenge in which he supposedly offered a prize to anyone who could demonstrate that results at twice the distance could be smaller (MOA-wise) than the closer results. That prize remains uncollected. See Applied Ballistics 'Shoot Thru Target' Challenge | Long Range Hunting Forum and Applied Ballistics Shoot Thru Target Challenge | Shooters' Forum (accurateshooter.com)

 

[Gleedus]

CRPS, I think you misunderstand. The point is that ammo that shoots better at closer range will ipso facto shoot better further out. An ammo that gives worse results than another at, say, 100 yards can't give better results at two or three or any times the distance. At the risk of being long-winded, I'll elaborate.

The same is true for 50 yards, but at that distance it's often impossible to distinguish easily which ammo gives the better results, especially when the results are based on insufficient sample size and testing is not done in consistent conditions. To illustrate, a rifle and ammo that produces 1 MOA results consistently at 50 is not always easily distinguished from a rifle and ammo that gives .9 MOA results. This difficulty can be particularly amplified by too small a sample size. Many shooters will be familiar with results where ten groups of five shots at 50 yards produce results that vary from .2's, .3's and .4's all on the same target. That doesn't make for the comparison of results in a straightforward way.

This is why I suggested in a previous post that 100 yards was a suitable distance at which to evaluate ammo performance. It's much easier to identify ammo that shoots better than others. With regard to what Tokay444 said, an ammo that gives reliably better results at 100 yards will not be outperformed by ammo that did worse at that distance.

Since .22LR accuracy is non-linear, which is to say that as distance doubles a group's size more than doubles.

To be sure, there are instances that happen rarely when ammo testing at testing facilities such as those of Lapua in Arizona or in Ohio when results with a particular lot in a particular rifle have better results (MOA-wise) at 100 meters than at 50. Since these results are recorded in a tunnel with electronic sensors, there's no paper deflection at play and the results are unaffected by wind.

But these kinds of results are not regular and, more importantly, not predictable. That is to say, they are the result of unexpected circumstances. It's not possible to test for ammo that will reliably give these results. One of the reasons that may explain them is that the ammo has center of gravity offsets that cause unusual and ordinarily unexpected results. It's not possible to test for an ammo's center of gravity -- at least not without destroying it.

On average, results examined from ammo testing in testing facilities, where it's possible to acquire reliable data for results at two distances in a test tunnel, show that on average group size increases by a factor of 2.8 between 50 meters and 100. Some rifle/ammo combinations will see the factor be smaller, others will experience an even larger increase. The thing is that this is not predictable. What should be expected is that results will more than double as distance doubles.

And the further the distance, the greater the factor. In other words, if the average is 2.8 between 50 and 100, it will be higher (on average) between 100 and 200 and higher still between 200 and 400.

With regard to Litz, in late 2014-early 2015 Bryan Litz issued his "shoot thru" challenge in which he supposedly offered a prize to anyone who could demonstrate that results at twice the distance could be smaller (MOA-wise) than the closer results. That prize remains uncollected. See Applied Ballistics 'Shoot Thru Target' Challenge | Long Range Hunting Forum and Applied Ballistics Shoot Thru Target Challenge | Shooters' Forum (accurateshooter.com)

I have never said that a ammo can or will shoot a smaller MOA. It simply cannot. As for the more accurate ammo at 50 vs which one is the most accurate at 200. Go and test for yourself and come back and we will discuss further.
If all else is equal then your right but not everything else is equal.
Velocity variation has been mentioned consider also BC variations and possible bullet weight variation.
Normal BC variation in vertical is almost as much as the velocity will affect it. Also the bullet weight will have an affect at even longer distances.

Lets consider the Eley force.
In my case 1.6 MOA at 211 yds is my average 20 shot group size.

Velocity ES was 61 fps
BC variation is typically 0.005 bc SD so reasonable to expect a 0.02 bc variation in a large sample.
Bullet weight can vary up to 2 gr as well. Now of course statistically we will probably never see two extremes together it will be a mix. Looking at the effects at different distances we can see they all have a different impact on the vertical group size.

At 50 yards
Velocity = 0.5 moa
BC = 0.1 moa
Weight = 0 moa

200 yards
Velocity = 2.25 moa
BC = 1.8 moa
Weight = 0.5 moa

400 yards
Velocity = 3.9 moa
BC = 6.2 moa
Weight = 1.6 MOA
So that weight sorting thing that makes no sense at 50 yards.... yes I know the arguments... test it!!

As we can see many of these other details that dont show up at 50 start showing up more and more as we move out it distance. At 50 yards velocity is a big deal at 200 bc and velocity are almost the same. At 400 BC is the big deal.

I specifically picked Force for this example as it is the only ammo in my testing that has less vertical at 200 then the velocity spread.

Contact is 41 fps ES so 2 moa at 200 yds and my average groups size is running 2.1 moa.

SK Rifle Match 48 fps ES so 2.3 moa at 200 and my group size are running 3 moa.

Is there something to positive compensation with out a tuner and the force happens to hit that? I do know that ammo base to ogive that measures 0.776" + shoots best at 200 but at 50 I see no difference.

At 50 yards I typically do 10 shot groups and at 200 20 shot groups. And 400 I do 20 shot groups. My average 400 yd group size is 5.6 moa. The groups and velocity number are from my new Rim X and all shot at 0⁰c to -10⁰c

 

[bantaman2]

where is the proof they dont buy pallets?

They don’t buy pallets. They buy cases

 

[Tokay444]

They don’t buy pallets. They buy cases

The one’s I’ve spoken to buy pallets.

 

[IdealJoe]

CRPS – If I may, I have some suggestions that may help you in your testing. I agree with what grauhanen is saying about if it doesn’t shoot at short range, it won’t shoot at long range. I also think I understand the results you are looking to see at distance and why. The biggest thing that jumps out at me in your testing is the environmental variables. There is so much going on that you can’t see at distance. Even if you had wind flags every 20 yards, they would be giving you so much information it would make your head hurt trying to predict how it would affect the bullet flight.

I don’t know your setup or experience with precision shooting so this isn’t a critique. In short range centerfire BR, we are trying to get 5 record shots either in the same hole or hitting the X’s in the score game. We are shooting setups that are many times capable of groups in the zeros. Even having several minutes to pick a condition and get those 5 record shots off, we don’t always see a condition change with a range full of wind flags. Many shooters are sending a shot every 5 seconds. You would think 5 shots in 20 seconds with perfect gun and ammo in a near return-to-battery setup would be a piece of cake. Yet sometimes you just have to scratch your head as to why a bullet went where it did.

You said you are shooting 20 shot groups at long distance. I personally can’t imagine being able get consistent results if shooting a string of 20 at once due to the time it would take to get those rounds down range. I would think you would be completely at the mercy of the environment during that string.

If it were me, I would qualify my 22 ammo lots at short range for accuracy and speed variation. Probably 50 yards. After knowing their potential there, I’d move to long range. I’d use a good benchrest setup so that you could shoot as fast as you can with minimal upset to the gun setup. You would also want to be sure the setup and your shooting style itself doesn’t produce vertical spreads. Then I would shoot in the best conditions I could in quick 5 shot strings. Shoot several strings at different spots and compare the shape, group size and location. You should be able to tell when a string was pushed someplace else by the conditions. Rule those groups out. Or at least accept it wasn’t the ammos fault for their placement. After several groups you should start to have a good feel for the ammos potential at distance.

 

[IdealJoe]

Back to the rifle bore measuring thing… The first two links AGrizz provided for the “gun barrel gage”, is for a relatively crude comparative tool. Think of it like using calipers to measure something you really need micrometers for. The tool locates off the top of the lands on one side of the barrel, then has a ball that touches a single point on the opposite side. It’s up to you to guess what it’s touching when its in the bore and relies on your hand alignment and feel. I’m sure it’ll tell you how much rifling you have left in a shot out bore. Not much more.

Third link – similar thing but for a cannon barrel.

Fourth link – Math lesson I guess. Oh, and most common sheets of paper like you would find in a printer are .003-.004 thick.

Fifth link – This Sunnen barrel hone is about 100k. I know because they gave me a quote on it when I was considering starting a barrel making operation. The machine hones by feeling the resistance in the tight areas and working those areas out. Similar to how a person slugs or laps a barrel and feels the tight spots. You’ll notice the article claims bore accuracies of .000027”. This has nothing to do with measuring.

His sixth link – A random article on various inspection equipment. But he notes being able to measure a barrel with a probe. I’ll try to post a pic here:

This is a picture I found of a barrel section I was probing in 2004 with a Hexagon Metrology CNC CMM touch probe like the one shown in the link. Sure, you can do some measuring with that. After you cut your barrel into pieces so you can reach into it. LOLOLOL!!!

The point I’d like to make is, it’s so much easier to stay silent and move on then to write something and have to deal with a barrage of bullshit from know-it-alls that absolutely must have the last word.

 

[Gleedus]

Back to the rifle bore measuring thing… The first two links AGrizz provided for the “gun barrel gage”, is for a relatively crude comparative tool. Think of it like using calipers to measure something you really need micrometers for. The tool locates off the top of the lands on one side of the barrel, then has a ball that touches a single point on the opposite side. It’s up to you to guess what it’s touching when its in the bore and relies on your hand alignment and feel. I’m sure it’ll tell you how much rifling you have left in a shot out bore. Not much more.

Third link – similar thing but for a cannon barrel.

Fourth link – Math lesson I guess. Oh, and most common sheets of paper like you would find in a printer are .003-.004 thick.

Fifth link – This Sunnen barrel hone is about 100k. I know because they gave me a quote on it when I was considering starting a barrel making operation. The machine hones by feeling the resistance in the tight areas and working those areas out. Similar to how a person slugs or laps a barrel and feels the tight spots. You’ll notice the article claims bore accuracies of .000027”. This has nothing to do with measuring.

His sixth link – A random article on various inspection equipment. But he notes being able to measure a barrel with a probe. I’ll try to post a pic here:


View attachment 7570815
This is a picture I found of a barrel section I was probing in 2004 with a Hexagon Metrology CNC CMM touch probe like the one shown in the link. Sure, you can do some measuring with that. After you cut your barrel into pieces so you can reach into it. LOLOLOL!!!

The point I’d like to make is, it’s so much easier to stay silent and move on then to write something and have to deal with a barrage of bullshit from know-it-alls that absolutely must have the last word.

What you say it true... I discussed this with Ryan @ IBI to check on "you guys". I get barrels from him.

 

[justin amateur]

Joe...have you ever found a published article, or measured for y'erself, wear within the bore of a 22lr?
I've looked multiple times, changing the tag words to increase the possibility of finding such articles.
What comes back is forum talk, but no hard documentation. I'd like to read actual/documented reports,
if only to make a dent in my own ignorance. So far my new barrel is showing wear on the high spots
but I lack the skills and equipment needed to produce actual measurements of the rifling.

 

[IdealJoe]

On a constructive note for Justin – The most practical means I can think of for you to accurately measure barrel wear is by using the Deltronics pins Tim mentioned earlier. I know AGrizz came back with this response:

“Using a Deltonic Pin in a barrel is like sticking your dick in old Haggie from the east side.”

This is ridiculous. A standard pin set will show you wear at the beginning of the throat on the lands where it will start to wear first. Absolutely the first best measurement no matter how much technology you can afford. You can also measure the groove diameter with pins that have been relief ground so as not to touch the lands. Another inexpensive and highly accurate measurement. But not necessary for your purposes.

It’s troubling to me seeing that Tim has the correct knowledge on the subject. Though, maybe he could be more tactful and informative in his responses. But he is being poked and instigated and the result is he gets the ban hammer and the loudmouth gets to continue running his mouth. Should be a pretty good clue to you guys wondering about the quality of input into some of these threads.

 

[IdealJoe]

Joe...have you ever found a published article, or measured for y'erself, wear within the bore of a 22lr?
I've looked multiple times, changing the tag words to increase the possibility of finding such articles.
What comes back is forum talk, but no hard documentation. I'd like to read actual/documented reports,
if only to make a dent in my own ignorance. So far my new barrel is showing wear on the high spots
but I lack the skills and equipment needed to produce actual measurements of the rifling.

I have not measured the bore of a 22LR. Centerfire throat erosion was a very obvious process that was known well and could be seen easily with a borescope. I'd recommend the Deltronic pin set for your land diameter if you really want to measure it. There are other more complex means using indicators but you don't need to go there. I'd also bet you may be the first to document this barrel wear if you pursued it.

 

[justin amateur]

After reading the article on pin gauges, looks to be similar in concept to go-no go gauges used in barrel installation.
A set of pins of known diameters, inserted into a machined hole until a diameter fits and the next step up doesn't
Have to be careful of temperature differences of the pins and material in which hole diameter is being measured.
Either measure at same temperature each time, or know the coefficient of expansion for the tools and barrels being measured.

Oh well, 90 bucks for a borescope, 160 for a barrel, guess I can invest in a set of pin gauges.
Another excuse to spend time at the range.

 

[IdealJoe]

You got it Justin. If you go this route, what you will find is on a fresh barrel, the "next size up" pin will not go with very light pressure. It's important not to press it in so it sticks. As the throat wears, it will create a tapered worn leade off the cut leade. Your next size up pin will still stick but at a different depth. You will want to develop a way to measure the depth that the pin progresses into the bore. (I'd have to think about that a bit before giving advice). In an example, you may at some point have a +.0003 pin advance .050 forward of the original leade, where a +.0001 pin may advance .150 forward of the original leade. By being able to measure the depth, you will be able to create the profile of the wear pattern. Make sense?

 

[grauhanen]

Joe...have you ever found a published article, or measured for y'erself, wear within the bore of a 22lr?
I've looked multiple times, changing the tag words to increase the possibility of finding such articles.
What comes back is forum talk, but no hard documentation. I'd like to read actual/documented reports,

There's the widespread belief that "everything's on the internet" -- but it does have limitations. While just about everything produced in the digital age is somewhere accessible through the interweb (there's still a lot of older stuff that's never been digitized), a great deal of professional literature, scholarly work, and technical information is not generally accessible by the average internet surfer. Many of these kinds of sources are available to those with approved access, such as paid subscriptions or professional association.

 

[IdealJoe]

Last thought for Justin and I have to get back to work for the day. In centerfire cartridges, it's believed that throat wear is largely a function of the powder kernels and combustion particles having a sandblasting effect. The more powder versus bore diameter, the more the wear. Extreme temps play a part too. I have no clue on rimfire and didn't know about silica in the priming compound until reading this thread.

 

[bantaman2]

The one’s I’ve spoken to buy pallets.

Seeing as I’m married to one... they don’t. The only place that could conceivably do that would be AMU

 

[308pirate]

After reading the article on pin gauges, looks to be similar in concept to go-no go gauges used in barrel installation.
A set of pins of known diameters, inserted into a machined hole until a diameter fits and the next step up doesn't
Have to be careful of temperature differences of the pins and material in which hole diameter is being measured.
Either measure at same temperature each time, or know the coefficient of expansion for the tools and barrels being measured.

Oh well, 90 bucks for a borescope, 160 for a barrel, guess I can invest in a set of pin gauges.
Another excuse to spend time at the range.

Pin gages tell you the effective hole size, not the actual hole size at any particular location.

And the effective hole size is affected by things like cylindricity which have nothing to do with the actual diameter of the hole at any location.

Interpreting what they tell you is not as cut and dried as many seem to think.

 

[308pirate]

Last thought for Justin and I have to get back to work for the day. In centerfire cartridges, it's believed that throat wear is largely a function of the powder kernels and combustion particles having a sandblasting effect. The more powder versus bore diameter, the more the wear. Extreme temps play a part too. I have no clue on rimfire and didn't know about silica in the priming compound until reading this thread.

My understanding of throat wear in centerfire rifle barrels is that the dominant cause is heat checking of the throat surface caused by the flame temperature of the burning powder, the duration of each exposure to the flame, and the frequency of flame exposures during a shooting session.

I'm sure that unburned powder and combustion solids also play a part.

 

[steve123]

The Lapua testing looks really interesting to me. After the testing you can buy a case of the best lot. I am curious about how likely it would be for the lot performance to change through the life of the barrel. I would think it wouldn't change too much through 5,000 rounds and even if it did you could test again after you blow through the case. Has anyone done the testing and then put a significant amount of rounds through and seen any change in performance?

Has anyone called and asked the Lapua test facility because it's likely someone there has communicated with the factory on when they consider a barrel "less precise" than when new.

I guess my answer to myself is - I'll be 6 feet under waaaay before then so I won't care....

My airgun smith knows a guy that spends $30,000 to $40,000 on 22rf ammo a year for 22rf BR, he might know.

 

[LeftyJason]

Seeing as I’m married to one... they don’t. The only place that could conceivably do that would be AMU

Please note. @Tokay444 is not in the USA. He is Canadian.

 

[IdealJoe]

Pin gages tell you the effective hole size, not the actual hole size at any particular location.

And the effective hole size is affected by things like cylindricity which have nothing to do with the actual diameter of the hole at any location.

Interpreting what they tell you is not as cut and dried as many seem to think.

I don't see where Justin cares or would benefit from actual hole size or cylindricity or perpendicularity or runout or parallelism or, or, or, or. A pin gages the effective hole size. AND, it will gage the effective wear. It's pretty cut and dry. Why would you throw in something like cylindricity? What relevance does that even have here? And then you indicate it's not easy to interpret what I'm saying? What's your goal? You're not helping him understand anything. You're just lobbing keyboard bombs and trying to discredit someone who is.

 

[308pirate]

I don't see where Justin cares or would benefit from actual hole size or cylindricity or perpendicularity or runout or parallelism or, or, or, or. A pin gages the effective hole size. AND, it will gage the effective wear. It's pretty cut and dry. Why would you throw in something like cylindricity? What relevance does that even have here? And then you indicate it's not easy to interpret what I'm saying? What's your goal? You're not helping him understand anything. You're just lobbing keyboard bombs and trying to discredit someone who is.

I wasn't speaking to you

 

[Gleedus]

This thread has a lot of topics... shall I start a new on the long range testing thing?

 

[IdealJoe]

Looks like the US Gov has an easier method than pins. Same idea though. Someone better tell them they aren't checking cylindricity.

PS: I could be wrong about the cause of throat wear. Thought that was right but maybe not.

 

[Badshot308]

Seeing as I’m married to one... they don’t. The only place that could conceivably do that would be AMU

I'm just curious, how many cases per pallet?

 

[grauhanen]

Has anyone called and asked the Lapua test facility because it's likely someone there has communicated with the factory on when they consider a barrel "less precise" than when new.

The Lapua test facility is unable to determine if a barrel is less precise than a new one because each barrel is potentially different -- even barrels from the same maker. On average most barrels will be average shooters for barrels from that manufacturer. Some may be better, others worse. Some barrels may loose some accuracy after fewer rounds than others.

The testing facility would have to have records of how that barrel shot the best ammo in the past to have a benchmark (pardon the pun) against which to compare how a barrel is currently shooting.

 

[steve123]

The Lapua test facility is unable to determine if a barrel is less precise than a new one because each barrel is potentially different -- even barrels from the same maker. On average most barrels will be average shooters for barrels from that manufacturer. Some may be better, others worse. Some barrels may loose some accuracy after fewer rounds than others.

The testing facility would have to have records of how that barrel shot the best ammo in the past to have a benchmark (pardon the pun) against which to compare how a barrel is currently shooting.

Yes that's all true but at some point it'd seem like they would replace their test barrels? How would they know they'd need replacing? I'm assuming that they have a set amount of rounds they have determined to replace them otherwise the ammo testing wouldn't be optimal.

 

[Tokay444]

Seeing as I’m married to one... they don’t. The only place that could conceivably do that would be AMU

Dude. First it was your son. Now it’s your wife. I told you, I’m not from the US and neither are the olympians I know. Give it up.

 

[grauhanen]

Yes that's all true but at some point it'd seem like they would replace their test barrels? How would they know they'd need replacing? I'm assuming that they have a set amount of rounds they have determined to replace them otherwise the ammo testing wouldn't be optimal.

At places such as the Lapua testing facilities in Arizona and Ohio they test customer rifles, not their own. To be more clear, if someone is looking to test different lots of ammo in a facility with a test tunnel and a fixed jig for the rifle or barreled action, he can take it or send it to the Lapua testing facility where they will test the customer's rifle. It would be up to a rifle owner to decide if the barrel was at the end of it's life.

 

[Tokay444]

You got it Justin. If you go this route, what you will find is on a fresh barrel, the "next size up" pin will not go with very light pressure. It's important not to press it in so it sticks. As the throat wears, it will create a tapered worn leade off the cut leade. Your next size up pin will still stick but at a different depth. You will want to develop a way to measure the depth that the pin progresses into the bore. (I'd have to think about that a bit before giving advice). In an example, you may at some point have a +.0003 pin advance .050 forward of the original leade, where a +.0001 pin may advance .150 forward of the original leade. By being able to measure the depth, you will be able to create the profile of the wear pattern. Make sense?

The absolute best and most accurate way to measure leade migration would be with a sphere and depth mic.

 

[Tokay444]

Yes that's all true but at some point it'd seem like they would replace their test barrels? How would they know they'd need replacing? I'm assuming that they have a set amount of rounds they have determined to replace them otherwise the ammo testing wouldn't be optimal.

Probably velocity, as with centre fire. When they need to add more than a predetermined amount of propellant to maintain velocity, the barrel is replaced.

 

[AGrizz]

LOL Grizz. Nevermind. You've never measured a rifle bore. You don't know what you don't know... But some of us do.

Well what you are saying here is nothing measured with air gages will ever be accurate? Previously someone said it was impossible to use air gages. That was Mr. IdealJoe at 9:04 on Saturday is that true?

Back to the rifle bore measuring thing… The first two links AGrizz provided for the “gun barrel gage”, is for a relatively crude comparative tool. Think of it like using calipers to measure something you really need micrometers for. The tool locates off the top of the lands on one side of the barrel, then has a ball that touches a single point on the opposite side. It’s up to you to guess what it’s touching when its in the bore and relies on your hand alignment and feel. I’m sure it’ll tell you how much rifling you have left in a shot out bore. Not much more.

Third link – similar thing but for a cannon barrel.

Fourth link – Math lesson I guess. Oh, and most common sheets of paper like you would find in a printer are .003-.004 thick.

Fifth link – This Sunnen barrel hone is about 100k. I know because they gave me a quote on it when I was considering starting a barrel making operation. The machine hones by feeling the resistance in the tight areas and working those areas out. Similar to how a person slugs or laps a barrel and feels the tight spots. You’ll notice the article claims bore accuracies of .000027”. This has nothing to do with measuring.

His sixth link – A random article on various inspection equipment. But he notes being able to measure a barrel with a probe. I’ll try to post a pic here:


View attachment 7570815
This is a picture I found of a barrel section I was probing in 2004 with a Hexagon Metrology CNC CMM touch probe like the one shown in the link. Sure, you can do some measuring with that. After you cut your barrel into pieces so you can reach into it. LOLOLOL!!!

The point I’d like to make is, it’s so much easier to stay silent and move on then to write something and have to deal with a barrage of bullshit from know-it-alls that absolutely must have the last word.

Then CNC equipment that measures dimensions to the millionths is not of any use here?

On a constructive note for Justin – The most practical means I can think of for you to accurately measure barrel wear is by using the Deltronics pins Tim mentioned earlier. I know AGrizz came back with this response:

What you are saying here is that air gages are of absolutely no use?

“Using a Deltonic Pin in a barrel is like sticking your dick in old Haggie from the east side.”

This is ridiculous. A standard pin set will show you wear at the beginning of the throat on the lands where it will start to wear first. Absolutely the first best measurement no matter how much technology you can afford. You can also measure the groove diameter with pins that have been relief ground so as not to touch the lands. Another inexpensive and highly accurate measurement. But not necessary for your purposes.

It’s troubling to me seeing that Tim has the correct knowledge on the subject. Though, maybe he could be more tactful and informative in his responses. But he is being poked and instigated and the result is he gets the ban hammer and the loudmouth gets to continue running his mouth. Should be a pretty good clue to you guys wondering about the quality of input into some of these threads.

This Deltronic pin is absolutely the best way to measure a barrel? I am just a dummy trying to figure out what an idiot I am. Please help me.

 

[bantaman2]

Dude. First it was your son. Now it’s your wife. I told you, I’m not from the US and neither are the olympians I know. Give it up.

no, that was a different guy. Unless the Canadian Olympic committee purchases ammo for athletes or they are super-rich, they won't be purchasing pallets.