Troubleshooting II or Help, why is brass changing its shape?

Ominivision1

First thing I would do would be to take a chamber cast of your gun, this not only tell you your chambers dimensions but will also tell you if you need to spend extra money for small base dies you will not need if your chamber is somewhere in the middle of specs.

PaulS

The indentations on the head would mean (to me) that pressures may be excessive. Now comes the big BUT: after sizing the case should still just fall into the chamber. If a fired (unsized) round won't go back into the chamber then I would back the powder charge off 2% and try it again. If you do this twice and it doesn't change then try a different powder. I had one powder (I can't look it up cause all my reload records are in storage waiting on a new reloading room) and even charges below minimum were showing signs of excessive pressure. I changed to a different powder and all was well.
The two things to check first are the fired brass / chamber test and then the crimp / bullet seating adjustment.
Omni has a good point about checking to see if you need a small base die. As stated they can be hard on brass.

slimjim

Ominivision1 wrote:

First thing I would do would be to take a chamber cast of your gun,

I did slug the base of the camber by the bolt at 0.4231 which is right in the middle of the SAAMI range. At somepoint, its going to be cheaper just to by a different barrel instead of invest more time and effort in this one. Having to cast my chamber just might do that.

slimjim

PaulS wrote:

The indentations on the head would mean (to me) that pressures may be excessive. Now comes the big BUT:

Thanks, PaulS. I should add another item to my list

Try a different powder - maybe Reloader 10.

I also found this article on swipes and the potiential causes including high pressure and timing.

www.shootingillustrate...ead-swipe/

SingleShotLover

After you get through your list of fixes, you might end up having to rely on dancing naked around a fire at the dark of the moon chanting incantations and waving your rifle over your head. Just don't get too close to that fire unless you want to risk some important parts of your anatomy! Flame

It will be interesting to see what you finally find out. Good luck and don't get discouraged.

slimjim

SingleShotLover wrote:

After you get through your list of fixes, you might end up having to rely on dancing naked around a fire at the dark of the moon chanting incantations and waving your rifle over your head.

Thanks for the morning chuckle, SSL. I just may have to do this. After just sorting through the issues with loading .270 Win, I expect there are multiple little issues all adding up here, also. On the .270, I had these issues:
1) first set of dies that didn't size the base quite small enough,
2) a bullet seater causing concentricity issues,
3) too much neck tension,
4) the shoulder wasn't getting set back far enough so I had to mill the case holder 0.003,
5) plus I had to stop using Federal Brass because it sprung back too much after going through the sizing die.

Elvis

man you are having a bad run at it...

RePete

It sounds like you need a SMALL BASE SIZING DIE. RCBS # 13331.

I use SB dies for my .223/5.56 AR and for 0.308 rifles. It will bring the brass back to factory dimentions.

With the SB die I don't have chambering problems.

slimjim · Last edited by slimjim on Fri Sep 21, 2012 5:37 am; edited 1 time in total

RePete wrote:

It sounds like you need a SMALL BASE SIZING DIE. RCBS # 13331.

RePete, you may be right. However, I need to rule out that my neck crimp isn't an issue first. I'm going to pick up one of these today at Cabela's just incase I really need it. The situation seems to be some brass cases just don't want to conform. By that I mean, most brass will resize down to 0.418 or less in my current die but there are a few subborn ones that, no matter how many times I cycle them through the die, they won't get below 0.419 at the base. I could just toss these and I'll be fine ... or ... I' can see if a SB Die will persuade them to "get in shape".

slimjim

Oh, this has been with only SSA brass. I have some Hornady brass to try also.

Elvis

ok I just went back and reread the origonal post. ?do the problem rounds chamber ok and just wont feed from magazine????
or is there a problem with thier chambering aswell???
Im presuming single stack magazine?

Elvis

also that indentation is it there on a single chambered round or only on a magazine fed one???? you will see where Im going with this by now.
have you tried another magazine??

slimjim

Thanks, Elvis. Rounds fed from the magazine are fine if they are sized right. There just isn't enough energy to strip the rounds from the magazine and force them into the chamber. That's why I inserted them single as far into the chamber as possible and dropped the bolt on them.

First item to be corrected. I wasn't crimping correctly.

The cases were not trimmed as they were not close to the measure I needed for trimming. However, there was noticeable variation in length from case to case. Thus on longer than average cases the crimp was distorting the neck and possibly the shoulder. Corrective action is to not use a crimp or trim to identical lengths. I'll probably try both next range session.

slimjim

I went to the range yesterday. All the rounds were loaded with no crimp. I had no failures to feed. I can't discount the chamber cleaning I did. I'll be more confident that improper crimping was my issue if the next range session goes as well.

Elvis

problem sorted!!!! great to hear.