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Oh, you remember that nonsense too! Ha! He *never* misses a PD and you won't either if you just buy the last missing link to perfection: the CPSNo. I am saying that if we can measure something that has no measurable impact on performance, it is meaningless. So either it is going to impact sd/es, or it is going to impact precision. Does it impact precision? Has that ever even been claimed? Or is this another it shoots 105 prairie dogs for every 100 rounds?
- Lot variation in powder didn’t seem to have any effect on accuracy, even on when using IMR 4198, which has a reputation for varying considerably from lot to lot. He would just buy powder as he needed instead of laying in a big supply, because he found no evidence to support that powder lot variance affected accuracy in the least.
Interesting…. Not on “accuracy” but what about velocity. Was velocity adjusted to maintain accuracy?
- Lot variation in powder didn’t seem to have any effect on accuracy, even on when using IMR 4198, which has a reputation for varying considerably from lot to lot. He would just buy powder as he needed instead of laying in a big supply, because he found no evidence to support that powder lot variance affected accuracy in the least.
Yea when Brian speaks I listen. He comes across to me as having solid testing methodologies. He seems to look at things very scientifically with data driven results, rather than anecdotes.Well, he won the F-TR nationals in 2015 and is a coach of the US Shooting team, so I am guessing he is considered to have had a good career at it.
More than that, the people in best position to judge how something like seating depth affects ignition, and thus performance, is somebody who 1) actually knows how to create a study, 2) has the means to test as stringently as possible, and 3) has the access to the most possible inputs. Litz would certainly have those when compared to any of the others being mentioned.
I have no idea if he is right, but he certainly isn't wrong because of his lack of creds.
the dudes were shooting in the warehouse and I don't dispute any of it - but for long range, velocity variation/SD counts and I do think temperature, lot-to-lot variation, and varying charge weights make an impact (as probably does case capacity consistency.)Interesting…. Not on “accuracy” but what about velocity. Was velocity adjusted to maintain accuracy?
Yes, that would be an important distinction.I do wonder about Bryan's comment on neck tension not making a difference, im gonna make an assumption that he's referring to only the amount of neck tension and not neck tension consistency.![]()
Although I knew what rifles were and had some knowledge of their use, 30 years ago I was "just a pistol" guy. Some good friends at our gun range got me interested in short-range BR, the accuracy game of games. At every match the wind flags outnumbered not only shooters but rounds fired by all during the entire match on some days. As I started watching OTHER SHOOTER'S (very important point) I noticed the very phenomenon Litz mentions on the near wind. I always felt the bullet to be the least stable that first 25 yards or so down range and my feeble reasoning told me wind would do more damage to it during that time. Then I felt the flags closest to the target were next most important due to having more influence on where the bullet was going to impact.Well, TBH, Bryan just explained something very very obvious in retrospect that I had not figured out in years of thinking about it: the near wind is more important because the effect on the bullet is "inherited early in the trajectory" and it's carried all the way to the target.
Wow. You learn something every day.
Thanks Bryan and OP.
(Plus I love to imagine Orkan crying himself to sleep, LOL.)
I have 2 CPS's, and love how they make priming so much easier on my hands and faster.. I also like the consistent seating each time, now I haven't tried to test primer seating depths yet, maybe it works, maybe it doesn't, either way I'm happy with my purchase.. I do wonder about Bryan's comment on neck tension not making a difference, im gonna make an assumption that he's referring to only the amount of neck tension and not neck tension consistency.![]()
And on the other hand, I'm pretty sure that Frank Greene (Bartlein) doesn't like abrasives at all.
JB makes two products that I can see...one is "non-embedding bore cleaning compound and the other is Bore Bright finishing compound. Mr. Greene, as I recall, objects strongly to one of them but I can't remember which.
Blue label is the cleaning compound and the red label is bore brite which is basically a lapping compound. He may dislike both IDK, but the red is probably the one. The only one I've used is blue, and sparingly.And on the other hand, I'm pretty sure that Frank Greene (Bartlein) doesn't like abrasives at all.
JB makes two products that I can see...one is "non-embedding bore cleaning compound and the other is Bore Bright finishing compound. Mr. Greene, as I recall, objects strongly to one of them but I can't remember which.
no need he said it before... i dont know why its so hard for guys to just clean a barrel after shooting and avoid all this.
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[IMG alt="Frank Green"]https://www.snipershide.com/shooting/data/avatars/s/9/9746.jpg?1640115959[/IMG]
Frank Green
Sergeant
Full Member
Minuteman
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This is what happens when you use a brush with an abrasive cleaner! I've posted this picture several times and it never gets old as to what can happen!
This was a 7mm (284W) F class barrel. At 100 rounds accuracy started to suffer. The picture is at 800 rounds. The bore and groove should measure .277" x .284". It now measures .279" x .2855"! So basically polished a full .002" out of the bore and .0015" out of the grooves. The lands (the bore) sticks up so it will take the brunt of the damage from improper cleaning.
The gouges are from the bristles of the brush and the brush is trying to rotate with the twist of the rifling but there is no way every bristle is going to follow/stay in the grooves. So the bristles will ride up and over the top of the lands and down the trailing side of the land.
Later, Frank
I'm ok with the JB bore compound (blue label) not the bore brite (red label).
Anytime I used JB blue it was always with a patch, now with the advent of VFG pellets that is my go-to when I need this type of cleaning.I'm ok with the JB bore compound (blue label) not the bore brite (red label).
I'm also o.k. with using Remington 40x cleaner (use to be called Gold Medallion years ago before Remmy bought them out).
Again..... I don't use a brush with any of them.
And on the other hand, I'm pretty sure that Frank Greene (Bartlein) doesn't like abrasives at all.
JB makes two products that I can see...one is "non-embedding bore cleaning compound and the other is Bore Bright finishing compound. Mr. Greene, as I recall, objects strongly to one of them but I can't remember which.
hahaha....thanks guys, but I did already find it and post it!Ah, found it:
"I/we will only use the JB Bore Compound. Not the bore brite."
And with a whole lot of caveats like don't use a brush
https://www.snipershide.com/shooting/threads/how-and-when-to-utilize-abrasive-bore-cleaners.7094636/
Some of the abrasives and how you use them you can remove material. Every once in a while I get a guy telling me...yeah I can't figure out why the patches keep coming out really black? They think it is carbon but not necessarily. You basically keep polishing. You can be removing material.It'll be the more aggressive variant I'm sure (Bore Bright finishing compound would be my guess).
I imagine Frank sees all kinds of messes / wrecked barrels from people getting carried away with those compounds with abrasives that are designed to remove a fine layer of material.
In moderation it would probably be fine but having said that I would be hesitant to use them knowing I'm taking off a layer of fine layer of metal that I cant get back again (although with some of the more stubborn issues like carbon rings etc it is pretty tempting).
Some of the abrasives and how you use them you can remove material. Every once in a while I get a guy telling me...yeah I can't figure out why the patches keep coming out really black? They think it is carbon but not necessarily. You basically keep polishing. You can be removing material.
Also I do feel you can make the bore way to smooth. This will make the bullet/copper want to stick even more like glue and this ends up turning into a copper fouling issue. Once it usually starts....we have less than a 50/50 shot we can save the barrel for the customer. Usually it never comes back to shooting good.
Seen shooters wreck barrels in as little as a 100+ rounds being fired and cleaning during that time frame. Seen barrels where in that amount of rounds fired and the cleaned it like 4 times....and removed a .001" out of the bore!
C'mon Ledzep, we all know that if you're reducing ammo usage, a 3 shot group is just as good as a 10 shot group.View attachment 7794131
I don't really see a trend that I would bet money on just yet. I agree with his conclusion that .009" seating depth is better than the others in this data set, but with equal graduations being taken per step, simply having one dip down isn't necessarily kicking my "trend" button. I'm not saying it's not a thing, just that the above testing, even when you go a step further and correlate POI/POA for the various 5-shot groups isn't enough to convince me one way or the other. Interesting, though.
Before I get my shit jumped... Here's 100 shots of the same factory match ammo (Hornady 6mm ARC 108 ELDM). It is then broken down into 33x 3 shot groups, 20x 5 shot groups, 10x 10 shot groups, 5x 20 shot groups, and 3x 33 shot groups, with the same sequence of firing. The dots represent the average group size, and the 'wings' represent the total span of recorded group size. THIS IS WITH NO VARIABLES CHANGED-- The SAME ammo. Accuracy fixture, straight 1.25" no contour barrel, 200yd climate controlled indoor range. This also an excellent indicator to the level of trash "group size" is as a metric, but I digress... With this level of noise present in a "no" variable string, it makes a guy question what you're reading when you do change variables.
ETA: Important to note here that the 20-shot and 33-shot data is in itself small sample size data (only 3x or 5x of them), and would likely also grow a little with more testing-- however, with such large samples per test, the amount it would grow would be significantly less than 3-10 shot data sets.
ETA2.5: Okay, screwed myself with an F4 button in Excel, here's the corrected one.
View attachment 7794214
Here is the same data analyzed with mean radius and SD on individual shot radii from the MPOI. This is 2*(mean rad + 2* SD) to generate an estimate of group size. I can explain this if you'd like but all of the data I've collected has shown 4-4.5x SD + 2*MR to be pretty close to inclusive of 50+ shot group size (diminishing returns on group size growth past 50 shots)... The resulting value is for "worst case" predictions on hit probability.
View attachment 7794145
Note how much more even and expected the trend is of the averages (using more of the data from each shot, not just the 'worst' 2). Also note the wild variation that comes from trying to predict results with 3 and 5 shot groups. Wish the trend would die.
Another thing people like to try, is to average a boat load of small sample tests and say "Surely, this is as good as a single large sample test"... And you can see that the distribution obviously favors smaller group size with smaller sample size. Without a POA reference to tie multiple small sample tests together, you're operating with less data, even if the round counts are the same. Similar trends exist with ES/SD on MV.
The more you learn...
I think so.So this is the thread orkan made a video about yesterday.
Oh,,,, I am in fact .3 mil all day!
![]()
“…the old .3 all day”
Benchrest aggs are in the .2’s for a season
That is .3 all day
....
Problem is though Ledzep, with 3 shot strings every now & again, it probably is 0.3 every time which, is bumped up to 0.3 all day.My problem is there's no real meaning to "0.# all day". That factory 108 ammo (Loaded with bulk dropped spherical powder) was .54 MOA avg on 5 shot groups. It was 1.2 MOA for an inclusive cone of fire (which isn't bad, really), and all that saying "This stuff shoots almost 1/2 MOA all day long" does is give me a tendency to over-estimate capabilities for internet E-penis bragging ability. And I guess it depends on where people are coming from and trying to do... My concern is primarily hit probability field-usable ammo for 1st round impacts (hunting)... And the research/testing I've done has been humbling.
That's why I thought using their 3 shot strings adjusted using Grubbs averaged population SD's to give a range might start the ball rolling on realistic reporting.I agree. I've started poking into what's really happening, and obviously I'm not changing anyone's abilities, but it's certainly changed my perspective on this stuff. Hopefully/maybe that's the path to better understanding and then more focused refinement.
You don't need a bathroom household chemical to clean the barrel and you don't need a $600 precision primer seating tool. Not really funny but the exact opposite of the company language at SH.com forums thanks to Primal Rights. “That's one small step for a man, one giant leap for mankind.”. Brian also took a huge shit on harmonics and the waste of time and resources associated with that sort of load development.@Ndbowhunter what was so funny exactly?
View attachment 7794131
I don't really see a trend that I would bet money on just yet. I agree with his conclusion that .009" seating depth is better than the others in this data set, but with equal graduations being taken per step, simply having one dip down isn't necessarily kicking my "trend" button. I'm not saying it's not a thing, just that the above testing, even when you go a step further and correlate POI/POA for the various 5-shot groups isn't enough to convince me one way or the other. Interesting, though.
Before I get my shit jumped... Here's 100 shots of the same factory match ammo (Hornady 6mm ARC 108 ELDM). It is then broken down into 33x 3 shot groups, 20x 5 shot groups, 10x 10 shot groups, 5x 20 shot groups, and 3x 33 shot groups, with the same sequence of firing. The dots represent the average group size, and the 'wings' represent the total span of recorded group size. THIS IS WITH NO VARIABLES CHANGED-- The SAME ammo. Accuracy fixture, straight 1.25" no contour barrel, 200yd climate controlled indoor range. This also an excellent indicator to the level of trash "group size" is as a metric, but I digress... With this level of noise present in a "no" variable string, it makes a guy question what you're reading when you do change variables.
ETA: Important to note here that the 20-shot and 33-shot data is in itself small sample size data (only 3x or 5x of them), and would likely also grow a little with more testing-- however, with such large samples per test, the amount it would grow would be significantly less than 3-10 shot data sets.
ETA2.5: Okay, screwed myself with an F4 button in Excel, here's the corrected one.
View attachment 7794214
Here is the same data analyzed with mean radius and SD on individual shot radii from the MPOI. This is 2*(mean rad + 2* SD) to generate an estimate of group size. I can explain this if you'd like but all of the data I've collected has shown 4-4.5x SD + 2*MR to be pretty close to inclusive of 50+ shot group size (diminishing returns on group size growth past 50 shots)... The resulting value is for "worst case" predictions on hit probability.
View attachment 7794145
Note how much more even and expected the trend is of the averages (using more of the data from each shot, not just the 'worst' 2). Also note the wild variation that comes from trying to predict results with 3 and 5 shot groups. Wish the trend would die.
Another thing people like to try, is to average a boat load of small sample tests and say "Surely, this is as good as a single large sample test"... And you can see that the distribution obviously favors smaller group size with smaller sample size. Without a POA reference to tie multiple small sample tests together, you're operating with less data, even if the round counts are the same. Similar trends exist with ES/SD on MV.
The more you learn...
Use one or the other.Does the JB/Kroil compound with pellets replace "more traditional" cleaning practices or is it in addition to? I'm currently using Boretech solvent, patches and a nylon brush. Factory barrels (Howa, Noveske, CZ).
Not in this case.So, from your known population of factory ammo you created x number of random samples. But your population is a sample of the entire lot number and is too small.
Also, I would go a step further. People load 5 rounds and call it a sample. Then they do it several more times. If all the loads are the same than the combined samples is the population. The population is still too small to draw any conclusion with confidence.
Well it would be had he used a smaller number in his data set but, as I understand his explanation, he used the entire set which constitutes 100% of the samples which in this case is the population.There is no such thing as a sample population. It is either one or the other. I think the logic is for a statistical batch to reach 90% confidence you start getting in that ballpark at over 30 rounds. It is simple statistics with an acceptable error rate more than it is sampling.
Well 100 certainly produces stable SD's & 40 to 50 is close to 95% interval. If you're concerned, you need only turn to Grubbs tables & use his predetermined factors to rationalize to his 10000 population SD's.Well it would be had he used a smaller number in his data set but, as I understand his explanation, he used the entire set which constitutes 100% of the samples which in this case is the population.
In any case, you do not need a huge sample number to show a gaussian distribution because it presents as a 1st order postulate & is not inferred.
Not finishing up with carpal tunnel springs to mind.Serious question for those of you with this gizmo or similar: why? I guarantee I can prime faster and with fewer steps using my frankford arsenal hand primer. I hear of bench priming being faster and such, but you have to load them one by one into a tube before the rest of the operation. You're also stuck to one place on the bench whereas with a hand primer you do it wherever you want. For me, I hand prime and drop powder at the same time and its super fast.
Good point. I see that as a valid reason for bench/press priming. I should have been more specific about how these gizmos are faster? Just seems more complicated/expensive as well as slower.Not finishing up with carpal tunnel springs to mind.
Well, my view is that he has far more experience with this subject of barrel damage from cleaning than pretty much anybody on the Hide so I accord him a great deal of credibility, personally.Maybe Frank is correct