Case Bulging

[greenrivers]

In loading a batch of .44 mags last week, I noticed an anomally that I can not explain. I have some guestamites, but no more. When seating the bullet and crimping, occasionally a case would allow the bullet to expand the case more to one side than the other. This happened only about three times in more than a hundred and fifty rounds. I was using RCBS dies and XTP bullets.
Anyone else run into this?

[Grumulkin]

That happens when the bullet isn't seated perfectly straight.  I don't consider it a serious problem but if you wish to solve it:


1.  When resizing, don't size the case all the way down.


2.  Use a Lee Factory Crimp Die which has a carbide sizer which will straighten things out.


A combination of the above, should minimize the problem if it really is a problem.

[Lloyd Smale]

i agree with grummulkin its a matter of not starting your bullets straight. It can be operator error but ive seen certain dies that are more prone to it. Make sure you have enough flair on your case to get it started straight and slow down and insure it starts up into the die straight. I dont care for lee factory crimp dies in handgun ammo. they may straighted the sides of your case out but they do some by sizing down the case which in turn sizes down your bullet to a smaller size and causes you to actually loose case tension because of  brasses natural tendency to spring back. Fix the problem instead of masking it with a fcd. by the way i do consider it a problem. It WILL effect accuracy if your bullet slams into the forcing cone off center.

[Swampman]

IMO it doesn't hurt anything.  I have a theory that a slightly oversized bullet and/or a slightly undersized expander plug makes it more likely to happen.

[anachronism]

I couldn't have explained it any better than Lloyd did. It could also be as simple as changing the seating punch in the seating die. LEE FCDs for handgun calibers are evil because they distort bullets and cases. It's probably a bit less of a problem as far as distorting jacketed bullets, but I worry about their effect on cases, and am currently pondering the possibility of them work hardening cases in the critical case mouth area. I suppose it would be difficult to prove.

[bilmac]

I have a different take on it. I think that what you are seeing is because the sizing die is a little undersized. Sometimes you see the bulge because the bullet didn't seat exactly straight, when the bullet is perfectly centered you don't notice it because the "bulge is distributed all the way around the case.

[greenrivers]

I believe I have been caught and you are all right in the assessment. I have used this set of dies for a lot of years and noticed it before. I have suspected that the bullet entering the case beyond the very slight bell when not perfectly straight has the heal of the bullet bulging one side of the case until it is most of the way up inside the die. The crimp reforms the mouth that would show a cradle without it and hides the effect. They have been few enough over the years to not be of consequence, but have always made me suspicious. Thanks for the confirmation and putting this issue to rest. I had considered a universal expanding die an will when the next batch of Hornets gets loaded. Though I am not sure that over working the case mouths is really needed with so few incidents. Thanks again guys.

[smokehouserex]

 
 
  Just a guess,  I have had this problem when I first started loading. I was using a round nose seat for semi wad cutters and it allowed the bullet to start crooked and bulged/distorted some of the brass. There are more than a few ways to bulge/distort brass, this is just one.
  HM

[wncchester]

*  Undersize mouths or too small expanders make bullet seating start cocked and bullets usually continue the way they start.
 
*  Failure to expand & bell enough to let the bullets sit straight up on the case mouth insures the seating will start at a slant.
 
*  Cases often have a thin or soft side that expand during seating more readily than the rest of the case.
 
Best 'cure' for your problem is to use a Lyman M expander die, or Redding's copy of it.  Adjusted correctly that expander design makes it easy to start all bullets straight; cast or jacketed, pistol or rifle.
 
Lee's pistol carbide Factory Crimp Die ONLY affects cartridges that are too large to chamber reliably.  It's a great tool IF we need it and IF it's used correctly; nothing is much help if we don't need it or fail to use it properly.