Valid method for finding jam, Or just stupid?

[bradworley]

Trying to find my jam point so I can start testing seating depths.
The loctite method didn't work for me. Could barely close the bolt! And I don't own the Hornady tool.
So what I decided to do was start with the loctite measurements and seat the bullet deeper until the cartridge did not "stick" in the chamber.
Basically I would push the rd into the chamber with my finger and then tip the rifle up. If the rd stuck, I'd remove it and seat it deeper until it fell out freely.
My thoughts process was if it was stuck, it was in the lands. Once it fell out on its own, it wasn't.
Loctite measurements were 2.335 base to ogive.
"Finger method " was 2.292 BTO
Is this method complet horse shit???
Am I just wasting time, or does this seem reasonable?
147gr ELD
Lapua SRP case trimmed to 1.910
Sized shoulder to 1.554 from 1.557 fire formed
Tikka t3 varmint 6.5CM 26 in barrel

 

[918v]

Makes sense. I use a sized case with a slit cut in the neck/shoulder.

 

[Aftermath]

You are ok.
Here is another method for when you can't go get the right tools:
Start by seating the bullet and measuring that seating depth. Then "blacken" the bullet...I was taught by an old man about 5 decades ago to use candle soot but graduated to using dry erase marker. Any color will work. Chamber this round and pull it back out. Look for signs of the rifling on your soot/marker. Seat deeper until you no longer see the marks.
But....just go buy the tool.

 

[TheOfficeT-Rex]

Wheeler method.

 

[John Glidewell]

I do the wheeler method above and / or the AOL Hornady gauge. But I use a cleaning rod down the muzzle with it. It takes some coordination. Use one hand on AOL tool and the other on the cleaning rod. Back the set screw on plunger out just enough so the bullet can move freely. While keeping the tool seated all the way in the chamber gently push plunger on tool forward until it stops. Then using the other hand on cleaning rod, work the bullet back and forth and you can feel it tap against the lands. It takes some practice as you have to keep tool seated with one finger and use another (I use pinky) on plunger while working cleaning rod. Think - pinch bullet between rod and plunger and move it in and out feeling the tap against the lands. Carefully set the set screw, pull, measure and repeat with another bullet. With practice you can get very consistent numbers. I run min of 5. Remember any number you get is a base line. My 2 methods are usually withing .005 of each other so I use the smaller # as that likely better represents jam. Subtract .020 and that is where I start my test. For breakin I run .040 or .050 off that jam number.

 

[918v]

I like the OP method. It is simple and does not require any reloading gymnastics.

 

[Jigstick]

Take your firing pin out of bolt if you’re doing it with the “seated bullet / marker” method

 

[Rocketvapor]

I use a fired case, body sized to just to click length in my AR.
The neck won't hold a bullet so I put some epoxy in the neck stick a bullet in, drop in chamber muzzle down.
Ease bolt closed.
Let epoxy cure.
I have a barrel that has eroded about 0.012" in 450 rounds, one that has eroded about 0.080" in 2500 rounds and a new one not mounted yet.
Have to waste an old (loose pocket) case and a bullet to measure every 400 to 500 rounds I guess.

 

[Haney]

Stripped bolt method gives repeatable results .

 

[kthomas]

Seat a bullet long, and use some steel wool to burnish the projectile. When you chamber the round and extract, the lands will show up very well on the bullet.

Keep seating deeper in increments and burnish the bullet each time with steel wool, until you no longer have marks from the lands. That will help you figure out where exactly the lands are, and how the bullets are seated in relation to the lands.

 

[Baron85]

I find the easiest most repeatable method for me is the pull the barrel and take a sized piece of brass, seat a bullet long and drop it into the chamber. It should stick and not fall out. Now keep seating the bullet longer until it doesn’t stick anymore. At this point it is no longer jammed into the lands. I usually do .010 increments and once I get it to not stick I seat another case/bullet out .010 from that one and work back down in .020 increments to find closer measurement. I usually only do this with new barrels to figure out a starting point.

Listening to some shooting podcasts it was mentioned to seat .050-.075 off the lands and just run it. I’m trying that on my newest barrel. I hate the time suck of powder charge testing then seating depth testing ect.

 

[cas6969]

Several decades ago before I had the right tools (if they were even commercially available back then) I used to do all kinds of crazy things to seat if the bullet just off the lands. All different types of coloring the bullet, loading colored bullets backwards so they’d hit the throat sooner, then using crude methods to locate the ogive, then do some crude measuring in mathematical magic to come up with a number. Or putting little strips of tape on the bullet so it would seat just off the lands. All sorts of crude rough estimated shit.

Now I have all the right equipment to do this stuff the right way, and I can’t get groups as good as I used to back then lol. Off the rack rifles with Tasco scopes, random mixed range pick up brass and inexpensive hunting bullets, it still out shot all the fancy expensive shit I got now lol. Things were better when I didn’t know any better.

 

[supercorndogs]

I use a fired case, body sized to just to click length in my AR.
The neck won't hold a bullet so I put some epoxy in the neck stick a bullet in, drop in chamber muzzle down.
Ease bolt closed.
Let epoxy cure.
I have a barrel that has eroded about 0.012" in 450 rounds, one that has eroded about 0.080" in 2500 rounds and a new one not mounted yet.
Have to waste an old (loose pocket) case and a bullet to measure every 400 to 500 rounds I guess.

Usually when checking for throat erosion it is suggested to use the same bullet each time its measured. As in "the" same bullet. Not the same kind of bullet.

IT seems like some fast drying super glue might be a better glue than epoxies and loctites.

Splitting the case mouth seems to me to be the most elegant solution. Save the case with the bullet to remeasure.

Gluing the bullet in there is probably less chance of disturbing it when removing it from the chamber.

I use the wheeler method most.

 

[bradworley]

Looks like I need to do the wheeler method.
As soon as I get a chance to disassemble the bolt, I'll give this a try.
Be interesting to see how close I get with the various other methods

 

[DownhillFromHere]

I was never able to get consistent readings with the Hornady OAL, so I made my own, sort of.

1. Use a Dremel tool or fine hacksaw blade to split a resized case's neck from mouth down into shoulder. This allows the neck to grip a bullet firmly enough for measurements, but loose enough to move with fingers.
2. Resize the case neck.
3. Seat a bullet long.
4. With bolt removed, push the "round" fully into the chamber using a finger or pistol cleaning rod. The split neck should allow the bullet to slide back into the case when it encounters the lands.
5. Taking care to protect the crown, insert a cleaning rod into the muzzle and carefully push the bullet and case out of the lands.
6. Pull the rod back a few inches, then push the "round" back into the chamber. Use the cleaning rod to push it loose again. Repeat a few times; the effort needed to dislodge the bullet from the lands should be lower with each repetition.
7. Push the "round" out of the rifle and measure CBTO.

I get CBTO measurements consistent to within a thousandth or two with this method.

 

[Rocketvapor]

I use the same KIND of bullet with a measured BTO. There is a small variance so I sort BTO.
I modified a Honady insert to hit the ogive very close to land diameter (0.219" ).
The stock insert hits at about 0.214". A little chamfer and the bullet hits at about 0.217".
Doesn't sound like much but the slope isn't much at that diameter.
Using the SAME bullet won't help with actual land distance with reloads using several bullets.
This glued dummy can be used over and over to check seating operation.

.

 

[918v]

Looks like I need to do the wheeler method.

It’s a lot of work to get information without value.

 

[BuildingConceptsllc]

It's a lot easier to just use the Hornady tool and be careful doing it 5 times. Then average them out and that's your jamb. You are going to start your seating. 020" off that any way so why does it matter if you are .005 or even. 010 off??? It doesn't. It's just a place to start.

 

[Haney]

It’s a lot of work to get information without value.

That's funny right there . Please tell of your method .

 

[Haney]

It's a lot easier to just use the Hornady tool and be careful doing it 5 times. Then average them out and that's your jamb. You are going to start your seating. 020" off that any way so why does it matter if you are .005 or even. 010 off??? It doesn't. It's just a place to start.

I find it easier to do the stripped bolt method, only takes one time . That way I know exactly whats going on , not like putting a stick in a hole to find the lands and not no what the hell you have . I have my bullets in the lands of many rifles , with your method my 5 jam could be a 15 . Makes no sense to be sloppy .

 

[338dude]

You are ok.
Here is another method for when you can't go get the right tools:
Start by seating the bullet and measuring that seating depth. Then "blacken" the bullet...I was taught by an old man about 5 decades ago to use candle soot but graduated to using dry erase marker. Any color will work. Chamber this round and pull it back out. Look for signs of the rifling on your soot/marker. Seat deeper until you no longer see the marks.
But....just go buy the tool.

Or just use a black sharpie to do the same thing

 

[BuildingConceptsllc]

I find it easier to do the stripped bolt method, only takes one time . That way I know exactly whats going on , not like putting a stick in a hole to find the lands and not no what the hell you have . I have my bullets in the lands of many rifles , with your method my 5 jam could be a 15 . Makes no sense to be sloppy .

Well if you are loading to the lands obviously you wouldn't do that. "Come on man"..... you know that.

I can get very accurate measurements with the Hornady tool but it does take some practice and having a nice clean chamber bore helps a lot. The stripped bolt method is fine but any method is dependant on not pushing the bullet into the lands so much that it skews your results. You can push the bullet too much into the lands and get a bunk reading no matter what method. But if your method works great for you then keep on keeping on.

 

[918v]

That's funny right there . Please tell of your method .

I did. Pay attention.

 

[Conqueror]

How To Measure The Distance To The Lands On Your Rifle Barrel

One of the benefits of reloading your own ammo is that you can customize it to your chamber. Factor...

precisionrifleblog.com

I have used Mark Gordon’s method on rifles with a removable barrel and it seems to work well.

 

[isofahunter]

Start at magazine length, if bolt closes I don't worry anymore about where the jam is.

 

[Haney]

That's funny right there . Please tell of your method .

I noticed that, means nothing . Without using a bolt you don't learn shit . Pay attention and maybe you will get smarter .

 

[Milemarker28]

Check out Eric Cortina’s YouTube page. I believe he has a video on this if you’re not bound to magazine length.

 

[nn8734]

My approach to determining an initial seating depth when feasible: If a particular brand of factory ammo (ie Federal GMM) does well in your gun with the same bullet you’re using in your reloads, just measure the CBTO and duplicate that to start.

Chances are you won’t have to do anything else, seating-depth wise.

If no factory ammo is available, I start at .070 off with tangent or hybrid ogive bullets and work towards the lands in .015 increments until groups start to open.

 

[Baron23]

It's a lot easier to just use the Hornady tool and be careful doing it 5 times. Then average them out and that's your jamb. You are going to start your seating. 020" off that any way so why does it matter if you are .005 or even. 010 off??? It doesn't. It's just a place to start.

With just a bit of practice, I have been able to get very consistent measurements with it and I'm not one of those handy shooters who yank their barrel off or disassemble a bolt blind folded.

Below are the OAL measurements I took on a Bartlein 6.5 barrel with SAAMI chamber by Ern at Altus. Yes, I threw some measurements out as they were very clearly badly taken...clear outliers. But, I did get quite a clean series of very consistent measurements as shown. Cheers

 

[Haney]

Just for educational purposes ,. The "Stripped Bolt Method" was around long before wheeler and the internet . I am not sure how that arrogant asshole ended up with the credit . Must be fanboys came up with that ?

 

[todd]

Just buy the Hornady tool and be done. It's a $45 tool for a $3,000+ rifle. Measure 10 times, throw out the longest and shortest measurements and run with it.

 

[CK1.0]

I like the "Deep Creek Method", pretty foolproof (and really easy with an Origin), but I'm not familiar enough with Tikka bolt disassembly... might not work for you.

If the Deep Creek method is a no-go with the Tikka, I'd just buy the Hornady thingy. The Hornady's few thou of variance +/- doesn't mean shit, especially if you end up loading in the .000"-.040" off range like many guys afraid of adventure do lol. You'll cook that much off in no time anyway (like 100-200rds or one match, unless you're going to be jumping a bunch, where a few thou isn't a big deal until your seating depth is established).

Even though I'm sold on using a bigger jump (currently jumping ~.100" off with VLD Match Burners), I still like to find out where the jam/lands are as precisely as I can, since, loading this way, the throat erodes so much more slowly (like only ~0.012" or less over the life of a barrel slowly).

 

[bradworley]

I like the "Deep Creek Method", pretty foolproof (and really easy with an Origin), but I'm not familiar enough with Tikka bolt disassembly... might not work for you.

If the Deep Creek method is a no-go with the Tikka, I'd just buy the Hornady thingy. The Hornady's few thou of variance +/- doesn't mean shit, especially if you end up loading in the .000"-.040" off range like many guys afraid of adventure do lol. You'll cook that much off in no time anyway (like 100-200rds or one match, unless you're going to be jumping a bunch, where a few thou isn't a big deal until your seating depth is established).

Even though I'm sold on using a bigger jump (currently jumping ~.100" off with VLD Match Burners), I still like to find out where the jam/lands are as precisely as I can, since, loading this way, the throat erodes so much more slowly (like only ~0.012" or less over the life of a barrel slowly).

From what I've heard, the extractor on the Tikka is a pain in the ass to remove.
So I'm not sure if this method will work for me

 

[CK1.0]

From what I've heard, the extractor on the Tikka is a pain in the ass to remove.
So I'm not sure if this method will work for me

I'd just grab one of the Hornady thingys then... remember that the jam/lands number you're looking for is just a number you'll use to set your relative seating depth number in relation to.

Just know that when loaded closer to jam, slight differences in seating depth will have a greater effect on your groups and what it does downrange (some old benchresters say even a single thou), same with throat erosion. That "goal post" is moving as your throat erodes, so things can (and will) change on you, and likely require your attention again down the road as the barrel's round count climbs.

The reason I still care about a few thou when jumping a bunch is for a different reason: it's to make it as predictable and forgiving as I can. When jumping a bunch (say ~.100" off), my waterline, dope (MV + BC + weather/altitude), and groups stay stupid consistent downrange over the life of the barrel... as long as I keep loading and feeding the thing the same "clone bullet" every time, it shoots.

As a decent reloader I can maintain a pretty slim tolerance on my shit, within a kernel, and within no more than a few thou here or there... so as long as I can do a decent job loading, shit shoots, no excuses necessary. When I say "forgiving" when talking about a load/barrel, I like them to be predictable, and boring in an always works type of way. Since the ammo is never perfectly the same round to round, there are tolerances in play, so forgiving is an attribute IMHO.

 

[Hetzer]

Tikka extractor isn't that bad. No worse than any other of that type.
I like the stripped bolt method and use it often. Expand the neck till I can move the bullet with a bit of resistance.
I try and measure as many bullets as I can at one time (variety wise).
I find it more time consuming but I like the results better than the Hornady tool. With that I use a thin plastic tube down the muzzle and push back on the bullet as I'm pushing forward with the tool. It's a pain too.

It's a matter of what you like best really.

 

[MarkyMark007]

My thoughts process was if it was stuck, it was in the lands. Once it fell out on its own, it wasn't.
Loctite measurements were 2.335 base to ogive.
"Finger method " was 2.292 BTO
Is this method complet horse shit???

you can have tight freebore, so fattier bullets (like lapua) stuck in your freebore before it hits the lands. every my rifle has that tight freebore.

so I (with horandy tool) push the bullet very hard into the lands, and I call this measurement ~0.010'' jamm.

 

[Pharmseller]

Steal a black Sharpie from work.

Prep a few pieces of brass but do not prime.

Seat a bullet to max mag length OR longer than you think you should.

Mark up the bullet with the Sharpie.

Chamber the cartridge.

Does the bolt close? If not, extract. You might need to pop the bullet out of the chamber with a cleaning rod. No biggie. Seat a bit deeper.

Extract the cartridge and look for engraving marks.

You want this:

Land marks square, or a bit rectangular along the horizontal axis. Just kissing the lands but not jammed enough to worry about a bullet getting stuck.

Measure the OAL, comparator is preferred. This is your rifle’s max for that bullet.

Just one way to do it but it’s worked for me for years. I did this a couple of weeks ago for my brother’s new 6.5 PRC and 156 EOL.

I’d say it worked.

P

 

[John Glidewell]

I do the wheeler method above and / or the AOL Hornady gauge. But I use a cleaning rod down the muzzle with it. It takes some coordination. Use one hand on AOL tool and the other on the cleaning rod. Back the set screw on plunger out just enough so the bullet can move freely. While keeping the tool seated all the way in the chamber gently push plunger on tool forward until it stops. Then using the other hand on cleaning rod, work the bullet back and forth and you can feel it tap against the lands. It takes some practice as you have to keep tool seated with one finger and use another (I use pinky) on plunger while working cleaning rod. Think - pinch bullet between rod and plunger and move it in and out feeling the tap against the lands. Carefully set the set screw, pull, measure and repeat with another bullet. With practice you can get very consistent numbers. I run min of 5. Remember any number you get is a base line. My 2 methods are usually withing .005 of each other so I use the smaller # as that likely better represents jam. Subtract .020 and that is where I start my test. For breakin I run .040 or .050 off that jam number.

Putting a 338 Edge together so I decided to try the dummy round drop in and my method using the Hornady tool and cleaning rod side by side. Dummy round method was 3.020 to lands. My method was 3.024 to lands. It makes sense that my method is slightly in the lands as I can feel the bullet tap. I do this multiple times trying to just barely feel the bullet touch lands. Both are repeatable.

 

[Baron23]

Putting a 338 Edge together so I decided to try the dummy round drop in and my method using the Hornady tool and cleaning rod side by side. Dummy round method was 3.020 to lands. My method was 3.024 to lands. It makes sense that my method is slightly in the lands as I can feel the bullet tap. I do this multiple times trying to just barely feel the bullet touch lands. Both are repeatable.

And .004 diff is rather insignificant for this purpose, yeah?

 

[John Glidewell]

And .004 diff is rather insignificant for this purpose, yeah?

Yes. Plus I don't have to pull the barrel with my method. It is just a base line number anyway.

 

[Baron23]

Yes. Plus I don't have to pull the barrel with my method. It is just a base line number anyway.

I too use the Hornady tool but don’t use a cleaning rod. May I ask what purpose the rod serves as I’m able to lock the tool’s position so no need to push it out from the front.

Yes, if the bullet was jammed too hard into the rifling then I do use a rod to push it out thru the action, but do you use it for any further purpose than that?

Thanks

 

[longrange772]

Another vote for Erik Cortina method.

 

[John Glidewell]

I too use the Hornady tool but don’t use a cleaning rod. May I ask what purpose the rod serves as I’m able to lock the tool’s position so no need to push it out from the front.

Yes, if the bullet was jammed too hard into the rifling then I do use a rod to push it out thru the action, but do you use it for any further purpose than that?

Thanks

I quoted my post when I replied earlier with measurements. It is described there.

 

[Yondering]

There always seems to be a lot of arguments about different convoluted methods to measure something fairly simple.

You don't need a split case, strip the bolt, or any reloading gymnastics. Just a dial/digital caliper and a cleaning rod with a locking collar and flat tip.

In essence, it's as simple as this:

- Measure from muzzle to bolt face, with bolt closed.
- Insert long loaded round to touch the lands, hold in place.
- Measure from muzzle to bullet tip.
- Subtract measurement 2 from measurement 1. That's max OAL to the lands with that particular bullet. Do a CBTO measurement and some math to figure out corresponding CBTO to touch the lands.

It's even slightly easier than that, because with a locking collar on the cleaning rod, measurement 1 is zero. Measurement 2 is between muzzle and collar, and is your max OAL.

 

[Haney]

There always seems to be a lot of arguments about different convoluted methods to measure something fairly simple.

You don't need a split case, strip the bolt, or any reloading gymnastics. Just a dial/digital caliper and a cleaning rod with a locking collar and flat tip.

In essence, it's as simple as this:

- Measure from muzzle to bolt face, with bolt closed.
- Insert long loaded round to touch the lands, hold in place.
- Measure from muzzle to bullet tip.
- Subtract measurement 2 from measurement 1. That's max OAL to the lands with that particular bullet. Do a CBTO measurement and some math to figure out corresponding CBTO to touch the lands.

It's even slightly easier than that, because with a locking collar on the cleaning rod, measurement 1 is zero. Measurement 2 is between muzzle and collar, and is your max OAL.

Too many variables, unless you are happy with close enough . . Stripped bolt does not lie .

 

[supercorndogs]

I too use the Hornady tool but don’t use a cleaning rod. May I ask what purpose the rod serves as I’m able to lock the tool’s position so no need to push it out from the front.

Yes, if the bullet was jammed too hard into the rifling then I do use a rod to push it out thru the action, but do you use it for any further purpose than that?

Thanks

For me, the rod helped feel where the lands were with the hornady tool, you can kind of push the bullet back and forth with the tool and cleaning rod, and feel where it tightens up, then touches the lands.

 

[MarkyMark007]

Too many variables, unless you are happy with close enough . . Stripped bolt does not lie .

like I said:

if you got tight freebore, you must push bullet to the lands !!

 

[Haney]

like I said:

if you got tight freebore, you must push bullet to the lands !!

 

[MarkyMark007]

this is simplified version which does not answer all the questions and could be wrong.

 

[Snuby642]

Usually when checking for throat erosion it is suggested to use the same bullet each time its measured. As in "the" same bullet. Not the same kind of bullet.

IT seems like some fast drying super glue might be a better glue than epoxies and loctites.

Splitting the case mouth seems to me to be the most elegant solution. Save the case with the bullet to remeasure.

Gluing the bullet in there is probably less chance of disturbing it when removing it from the chamber.

I use the wheeler method most.

I just don't get that.

The ogive is what hits the lands and what measurements are taken from.

To me it doesn't matter what bullet or style is used the ogive is a zero place, aka a datum.

Everything else moves, the nose and bullet base, the case base (bto) and the lands erode.

But to me the ogive is the datum zero point, it's always zero.

If I measure carefully 3 different styles of bullets should all give the same dimension to the lands.