Strange problem reloading .50 Beowulf

[1911aholic]

I just noticed something strange about my fired Beowulf brass. I am thinking it may be a sign of excessive pressure. The case head on my fired brass has actually shortened or shrank. I have only loaded the brass once. I was measuring the OAL of the fired brass and it seemed to shorten alot more than I would have expected. Looking at the brass it looks completely normal. No bulges, cracks, pierced primers, etc, etc. You would never no any thing was strange until you compared it to some unfired brass..

If I stand up a good portion of my fired brass next to unfired it appears as if the bottom rimmed part of the case has been pushed in some what making the taper of the head a little steeper. I don't know how to describe it. Like I said though just looking at an individual case you would never know anything was off. Just on close comparison to another unfired case is it apparant.

I am planning on pitching the brass and dropping the load some.

I know the brass will strech upon resizing but nothing will happen to the case head (at least that's what I think).

My loads were 37.5 of lil gun with CCI large magnum pistol primers. I was getting some slight variance with my powder dropper so that is why I dropped the load just a bit. I was using rainier 335gr HP's. I don't remember the OAL off the top of my head but it was whatever AA reccomended.

So I am unsure if this may be somewhat normal with this round or what since there is such a large taper down to the rim. Is this a weakened portion of the case.

I have reloaded for a few years now and have never really had any thing like this occur before. I've never had a squib, double charge, etc, etc. I pay close attention to what I am doing.

I don't have any pics currently of my brass but here is a pic with arrows showing which part of the case I am referring to:

[pilgrim]

Well thats a new one on me! Other pressure signs show up first like the flattened primer that has either backed out of the cup some or has been flattened to such an extent to flow into the brass around the primer.
Things to check when reloading
1 air flow in the room you want none! the breeze from an air vent over your scale can throw it off a little or a lot ceiling fans off too!
2 use check weights to verify your scale settings
3 don't get distracted from one job till its done
4 measure your case length to be in spec before reloading
5 do not over crimp this cartridge head spaces on case mouth

Is there a bright ring around the bottom of the case where it meets the inside of the case head about where you would expect to see a Magnum band on other cartridges? You can bend a paper clip end and use it like a feeler gage to see if your heading toward case head separation! use it like a little hook on the inside of the case and feel up from the bottom of the head if it hooks or feels thin there? Brass must flow somewhere from over pressure and what you have is a new one on me have you miked it out?
I am sure others on here will chime in on this one!
good luck and do not pitch the brass quite yet!

[Spyder]

I read that just before heading out to the range. I DEFINATELY see the same thing with mine. Eleven of the twelve rounds that I fired hasd the base pushed up a little bit, shortening OAL. The angle is easily seen to be sharper from the base of the shell to the body.

Factory 334HP's and factory 300 Gold Dots.

[1911aholic]

Hmmmm... If it is common I wonder if I should change the overall length any after the first firing.

My scale is not off. I have a room set up for reloading. There are no fans. There is a vent on the floor across the room but I turn it off when I reload just in case. I really pay attention to detail when I reload. Like I said no other pressure indications whatsoever at all.

I will try to take pics later. Just wondering whether to scrap the brass or not.

[PRUHDLR]

Is the weapon being run "wet" ?? Is the bolt,bolt carrier,gas rings,inside of the upper,etc.,well lubed ?? Are you using a normal action spring ?? Is the buffer assy lightly lubed ?? Does the underside of the bolt carrier that rubs on the top of the hammer have a small amt of grease/lube on it ?? Is the hammer pin lubed ??

If all else fails,I'd contact Bill at AA and see what he has to say. He is always willing to help his customers.

Pls keep us posted as to the cure. -----pruhdlr

[pilgrim]

This may be a common occurrence as the brass takes a set and work hardens most brass Will work harden thats why you sometimes have to anneal the mouth to keep it from cracking the next time you reload. This is not done most of the time until your on your 3 or 4 or 5 reloading and straight wall brass dose not stretch the way bottle neck brass dose so some guys get a way with out trimming for a long time I'll bet a dollar to a donut this is common place your just the first guy to ask about it.......... Good eye!

[Brian HHI 7265]

Interesting.

I examined approx. 20 fired brass and found one as you describe. It appears to be from the case not grabbing the chamber walls, that happens from low pressure, not high pressure. Very interesting, I never saw that before either, It must be the severely rebated rim causing it combined with too low a pressure for adhesion, but high enough to cause the damage. A very good argument for making sure any case lube is removed from the brass after loading. I need to attend to that, I may have left too much on.

Feeling the brass I feel a ridge at the juncture of the rebated rim angle and the web of the brass. That ridge measures .5482-.5486". Looking inside the case I see a ring in the same area. That ring is enough to convince me not to use the brass again. A pressure failure in that area is total disaster. FWIW, where the ring is tells me that the brass cartridge wall as it was forced to the rear, used the solid head to wedge itself out causing the ridge.

I took it a little further. The brass doesn't pass the Zapp gauge, and frankly, it might not size worth a damn either. If it did survive sizing, say from someone sizing the brass to new brass specs and not as much as the sizing die allows, the brass there won't be touched, and again won't pass the Zapp guage, and certainly won't chamber. So while it could technically be dangerous, since it won't chamber even after loading, it won't fire and is not dangerous for that reason. If it could chamber I think it'd be a grenade.

Again, this doesn't appear to me to have a high pressure cause. If that was the problem, the case would adhere to the chamber walls and the head would be thrust back causing an insipient case head separation after time. What appears to have happened here is that the case did not adhere to the chamber wall, the case thrust back against the solid case head and "wedged" itself larger, as well as affecting the angle of the rebatement.

Either way, I see the brass as garbage. It may not be that the brass was garbage before firing, but a light load may have caused it making the brass garbage after firing.

Maybe making this worse was soft brass in that area? Normally brass is left work hardened at the head.

If I'm correct 1911aholic, dropping the load more than you already have will make the problem worse, maybe disasterously so. FWIW, the load data we have is what we should load, no deviation. You're experimenting my friend. This is one case where we should use the load data as given and not reduce and work up. It's already a low pressure cartridge.
I would use the load as it's given to us and make sure all case lube is removed.

Speaking for me now... I might even up my powder an additional 1/10 grain- I'm using the published data of 37.7 grains now. 1911aholic, if I were you, I'd get my load up where it should be for a start.

Something else that might help is to anneal the brass. Dead soft brass will expand readily to grip the chamber walls. If you don't know how to do this get back to us.

[1911aholic]

If I'm correct 1911aholic, dropping the load more than you already have will make the problem worse, maybe disasterously so. FWIW, the load data we have is what we should load, no deviation. You're experimenting my friend. This is one case where we should use the load data as given and not reduce and work up. It's already a low pressure cartridge.
I would use the load as it's given to us and make sure all case lube is removed.

Speaking for me now... I might even up my powder an additional 1/10 grain- I'm using the published data of 37.7 grains now. 1911aholic, if I were you, I'd get my load up where it should be for a start.

I understand what you are sayubg but 0.2 gr from the recommended load should be negligible. I mean alot of powder throwers are going to have more variance than that. I am not saying I will not try upping the load but I have a hard time buying .2 gr is going to make much difference. That and the fact that Spyder said he got the same results with factory loads makes me wonder.

Oh and yes everything is well lubed with break free CLP just prior to shooting.

[1911aholic]

I forgot to say it is a entry AA upper on a stock stag arms a2 lower.

[dougstump]

I found three like that in the cases that I fired yesterday. This batch of cases have been fired & reloaded several times. But I thought of another possible cause. Could it simply be a variance in the manufacturer of the cases? I've got 150+ new cases stuck back under the loading bench. I'll dig them out and see if there are any in there.

Doug