After one firing, 38 out of 200 pieces of AA brass won't chamber. Why?

[Hank Rearden]

After one firing 38 out of 200 pieces of AA brass won't chamber.
All brass has now been cleaned, and full length resized (Forster Die).
All of this was done without a bullet seated, (not a bullet in the lands issue).

These 38 are now over max length by an average of 8 thousands. Even after trimming they still won't chamber. Resized a second time after resetting up the die to camover and set the shoulders back a little more, and that failed.

By all outward appearances the brass looks normal, no dents or bulges apparent to the naked eye. The only visible sign are some very faint striations (stretch marks) running vertically up and down the main body from the shoulders towards the base.

All brass was new, same chamber, different loads for testing.

My Theory is that it was caused from over pressure, and premature extraction. Some of the loads were on the hot side and the gas block may not have been turned down enough to prevent over gassing.

Most of my reloading experience in rifle cartridges has been with bolt actions and this kind of thing is new to me.

Around 100 factory Hornady rounds are fine. They resized and chambered without a problem.

Can this brass be saved? Is my diagnoses correct? and if it is what actually happened to the brass that prevents it from cambering?

If I've lost the 38 so be it, but I'm trying to not make this mistake again and loose any more.

Thanks for the help guys

[LRRPF52]

Need to know:

* What barrel/chamber you have. What barrel length, and gas system length? (e.g. 18" MLGS, 20" RLGS, 16" MLGS, 16" CLGS, 24" RLGS...)

* What is the load?

* What is the length of unprimed brass from base to the shoulder?

Normally it is the Hornady brass that people have similar problems with, not Lapua. Are you saying that your cases are coming out 1.528" OAL, once fired?

[tackdriver]

I am in the same boat but with the Hornady brass, I was assuming I needed to bump the shoulder back. I am Leary of doing this because I have ruined more than one pc of brass with my die down to far and a flared out shoulder. I will be watching this thread hard

[LRRPF52]

Shoulder set back is one of the most common issues reloaders encounter with gas guns. To avoid crushing the cases, slowly turn your die down in small increments, like quarter turns at most, to see where you are at with your chamber.

Start with the once fired brass, cleaned and lubed ( I used One-Shot from Hornady, which works much better for me than old school wax.)

Follow the directions for setting up your sizing die. Find where the die starts to touch the shoulder, and see if this is enough set back to fully close in your chamber. If it's too long, turn the die down in quarter turns or less, until it is sized right. You will want full bolt closure, so we want to use unprimed cases, dropped into the chamber, let the bolt carrier slam home from a locked position. The bolt carrier should be well lubricated, with a thick oil that lasts well, while having great lubricity.

If you don't do that, and you are only partially setting the shoulders back, the firing pin will not contact the primer in an unlocked situation.

The best way to avoid crushing cases is by following the directions from the die maker. That usually involves installing the shell holder, placing a cleaned piece of brass in it, and camming the handle so that the ram rises into the highest position.

Then install the die and turn it down until it contacts the brass. There is no way you can really crush a case if you approach it from maximum ram height, and minimum die contact, unless you turn the die down too far.

Yes, I had to learn this the hard way too, after crushing some cases, and starting over by reading the distractions.

There is a detailed description of die set up and specific loading procedures in the 6.5 Grendel Reloading Handbook Volume II, if you look at pages 58-71.

[Hank Rearden]

Need to know:

* What barrel/chamber you have. What barrel length, and gas system length? (e.g. 18" MLGS, 20" RLGS, 16" MLGS, 16" CLGS, 24" RLGS...)

* What is the load?

* What is the length of unprimed brass from base to the shoulder?

Normally it is the Hornady brass that people have similar problems with, not Lapua. Are you saying that your cases are coming out 1.528" OAL, once fired?

Chamber was a 264lbc,18" McGowan barrel, rifle length gas, jp adj. gas block.
The rifle now has a 16" 304profile from the Lilja group buy.

The loads were various powders and I can't pinpoint which one created the issue.

When i get home I can make some more measurements of the brass and post a pic.

I wouldn't think this was caused by a chamber issue, simply because of the infrequency of it and the fact that no Hornady factory loads were involved.

How do you get a accurate measurement from the shoulder?

Yes the OAL length of the problem once fired case's are between 1.522 and 1.529. The rest are still around 1.511-1.515

[txgunner00]

The time I had this issue it was due to a incorrect shell holder not bumping the shoulder back enough. I had a different brand shell holder that would hold the case fine but was a few thousandths too deep. Like you, I had a number of rounds that looked perfect but would not chamber. With the correct shell holder I've been 100% since.

[bwaites]

After one firing 38 out of 200 pieces of AA brass won't chamber.
All brass has now been cleaned, and full length resized (Forster Die).
All of this was done without a bullet seated, (not a bullet in the lands issue).

These 38 are now over max length by an average of 8 thousands. Even after trimming they still won't chamber. Resized a second time after resetting up the die to camover and set the shoulders back a little more, and that failed.

By all outward appearances the brass looks normal, no dents or bulges apparent to the naked eye. The only visible sign are some very faint striations (stretch marks) running vertically up and down the main body from the shoulders towards the base.

All brass was new, same chamber, different loads for testing.

My Theory is that it was caused from over pressure, and premature extraction. Some of the loads were on the hot side and the gas block may not have been turned down enough to prevent over gassing.

Most of my reloading experience in rifle cartridges has been with bolt actions and this kind of thing is new to me.

Around 100 factory Hornady rounds are fine. They resized and chambered without a problem.

Can this brass be saved? Is my diagnoses correct? and if it is what actually happened to the brass that prevents it from cambering?

If I've lost the 38 so be it, but I'm trying to not make this mistake again and loose any more.

Thanks for the help guys

Something is grossly wrong here. I've fired around 10,000 rounds of Grendel ammo, factory and hand loads, in my own rifles, and I've reloaded and witnessed firings of probably 5000 more rounds. Those have been in barrels from 16-28 inches in length, with all three gas lengths. I have never seen Lapua Grendel brass grow that much, period, much less in 1 firing. Most of the above count has been in SAAMI Alexander Arms chambers, but a fair number has been in 264 LBC chambers as well. Recently I've fired brass in Lilja's chamber, (I'm still not quite sure what to call it!)

I've never trimmed a single piece of Grendel brass, because I've never needed to, and some of my plinking brass has 20 reloads on it.

If you are sure that it is sized to length properly, then the only place that brass would probably be an issue is at the webbing, so additional measurements need to be made there and compared to unfired brass. In bolt guns, .002-.003" growth there over new brass is the maximum recommended for safe pressure loads, in general. In a gas gun, which has typically a looser chamber, I still would be very suspicious when I went past .004".


EDIT---Once again the Ipad closed a thread that I did not intend to close! Reopened!

[cory]

Chamber was a 264lbc,18" McGowan barrel, rifle length gas, jp adj. gas block.
The rifle now has a 16" 304profile from the Lilja group buy.

The loads were various powders and I can't pinpoint which one created the issue.

When i get home I can make some more measurements of the brass and post a pic.

I wouldn't think this was caused by a chamber issue, simply because of the infrequency of it and the fact that no Hornady factory loads were involved.

How do you get a accurate measurement from the shoulder?

Yes the OAL length of the problem once fired case's are between 1.522 and 1.529. The rest are still around 1.511-1.515

Forster makes a gauge that I believe would measure what you're looking for.

[poli]

How do you get a accurate measurement from the shoulder?

Yes the OAL length of the problem once fired case's are between 1.522 and 1.529. The rest are still around 1.511-1.515

I'm using a Hornady Headspace Gage (http://www.midwayusa.com/product/479...vc=sugv1479704) to measure the distance to the shoulder. I've heard about the same issue with the incorrect shell holder mentioned by txgunner00, and I recall that replacing the shell holder fixed the issue.

[montana]

I had problems with my Hornady brass when I first started reloading for my first Grendel. It ended up that the shoulders on some of my brass was being bulged when I seated my bullets. My seating die was set properly but the brass needed to be chamfered more with this batch of Hornady brass. I have not had this problem since then but it could be something you could check out.

[IceAxe]

I had a somewhat similar problem when I tried to resize some 7.62x39 brass, it just wouldn't chamber in my 264lbc BlackHole barrel. I ran the shell holder over a wet stone and and was able to get them to work. Dies and shell holder are both RCBS.

[Hank Rearden]

Something is grossly wrong here. I've fired around 10,000 rounds of Grendel ammo, factory and hand loads, in my own rifles, and I've reloaded and witnessed firings of probably 5000 more rounds. Those have been in barrels from 16-28 inches in length, with all three gas lengths. I have never seen Lapua Grendel brass grow that much, period, much less in 1 firing. Most of the above count has been in SAAMI Alexander Arms chambers, but a fair number has been in 264 LBC chambers as well. Recently I've fired brass in Lilja's chamber, (I'm still not quite sure what to call it!)

I've never trimmed a single piece of Grendel brass, because I've never needed to, and some of my plinking brass has 20 reloads on it.

If you are sure that it is sized to length properly, then the only place that brass would probably be an issue is at the webbing, so additional measurements need to be made there and compared to unfired brass. In bolt guns, .002-.003" growth there over new brass is the maximum recommended for safe pressure loads, in general. In a gas gun, which has typically a looser chamber, I still would be very suspicious when I went past .004".


EDIT---Once again the Ipad closed a thread that I did not intend to close! Reopened!

DING DING DING.... I think we have a winner!

New unfired Lapua brass measures .439 at the web.
All of the fired brass that chambers OK measures .440 or less. (AA & Hornady)
All of the fired cases that will not chamber measure .441 or .442 at the web.

I think the early extractions caused the web to swell and it's to far down on the case for the resizing die to compress.

The longest of the 38. Measured 1.532


Fired, Trimmed, Resized, Won't chamber.


One that won't chamber, compared to New Lapua


Opinions?

[NugginFutz]

Well, I don't know if the Forster dies are SB, but if you know someone nearby with an RCBS .264 LBC Small Base set, you might run those 38 fat boys through the SB sizing die and see if if helps. Hardly worth the cost of getting another sizing die, unless you anticipate a repeat performance.

[bwaites]

I have, unfortunately, made a few too many pieces of brass like that!

[Hank Rearden]

I have, unfortunately, made a few too many pieces of brass like that!

Thanks for stearing me onto the correct path.

I'll do my best not to repeat this mistake.