Problem with .223 reloads - bell at shoulder base

[TexasShooter59]

Recently, I was in a rifle match with 3 jams. The offending cartridges are in the attached photos. What happened in each case was that the cartridge would not chamber fully and had to be ejected. And, it took a lot of force pulling the charging handle to get the cartridge out!

I've only seen this "belling" happen to a case less than a handful of times over the span of more than a couple thousand rounds reloaded. I have always caught them with visual inspection before. If they weren't too bad, I would shoot them as foulers.

As part of my reloading process, I full length resize using a lube on the outside of the case and Imperial Dry Neck Lube by dipping the neck in it. After cleanup, I run each case through the Wilson case gage, followed by trimming if necessary. I inside chamfer every case and outside chamfer the trimmed cases. I also crimp at bullet seating. I do not run the completed cases through the Wilson gage after seating.

The cases are all range pickups or my own. The current bullets are the Hornady 55 gr. Z-MAX with cannelures. 5.56 chamber.

I measured the OAL of each of these three at about 2.230" when I was going for 2.225". I'm sure I wrote them off as being okay due to the bullets being a little long. Putting the completed rounds in the Wilson case gage now shows them to protrude at the base just a very small amount.

Any thoughts on what might be causing this? Thanks!

 

[rcmodel]

Crimping.
That's all I know of that can do that.

I suggest not crimping.

But if you must, get a Lee FCD crimp die.

It operates a collet off the shell holder, so case length plays no hand in buckling the shoulders.

rc

 

[moxie]

Yup, forget about the crimp. You don't need it. Case neck tension should hold the bullets in place just fine. OAL is fine as is.

 

[ku4hx]

Looks to me like the inside neck sizing plug is actually lengthening the case as you draw it out. This gives a curved look to the shoulder as is sort of sucks it inward.

I get around this by NOT inside neck sizing with a normal plug on the decapping pin. I use a Lyman "M" dies to correctly size the neck in the first stage of my RL550B. I deprime and size on a single stage press and the spent primer is punched out by a Lee universal depriming stem in the Lee sizing die.

 

[mdi]

I would agree it's over crimping. I had the same problem with some 30-06 for my Garand. I screwed up when I seated some GMX bullets and inadvertently lowered my seating/crimping die and put a hair too much crimp as the bullet was being seated. I just did a few rounds so I dropped the remaining "bad" ammo in the "do later" box...

 

[Cemetery21]

Only time I ever crimped (unintentionally) I had the same problem (1985 I think).

 

[joem1945]

If you feel you must crimp then unscrew the seating/ crimp die 1/8 turn and adjust the seating plug down for proper OAL.

 

[TexasShooter59]

Thanks for all the comments! I think I will stop crimping and see how that goes.

 

[lysanderxiii]

If you absolutely, must crimp, use a Lee crimper. It closes in radially to crimp.

 

[steve4102]

A classic example of the seating die screwed into the press way to far.

Follow the instruction for "Seating Without Crimping" found here.

http://www.rcbs.com/downloads/instructions/ReloadingDieInstructions.pdf

 

[Snyper]

If you're going to crimp, you need to trim them all to the same length to get the same results on each round

 

[GLOOB]

If you're going to crimp, you need to trim them all to the same length to get the same results on each round

Even then, the thicker brass and/or thicker bullets are going to get more crimp.

If crimping into a jacketed bullet is a must, I prefer to use the FCD. The LEE FCD works great with cannelured bullets, but it relies on consistent pressure at the end of the stroke, not a hard stop or camover. Be sure to practice a bit before you crank out a lot of rounds.

 

[average_shooter]

I'll throw another vote in for crimp/seating issue. I had the exact same problem when trying to seat and crimp in the same operation. Since I switched to using a Lee Factory Crimp Die, as a separate station from seating, the problem seems to have gone away.

 

[TexasShooter59]

I have been seating and crimping in the same operation. I did follow the die instructions for doing that. I will try seating without the crimp and see if it will help group size any. (I did not start crimping due to some issue, but rather because it "logically" seemed like the best thing to do in a semi-auto.)

Thanks for all the replies!

 

[gamestalker]

Yep, over crimped. If your gonna crimp a bottle neck, make sure you only use a tad, and it must be consistently so.

It's also imperative to make sure all the brass is trimmed to the same lengths.

IMO, crimping a bottle neck case is only asking for trouble, unless it's tubular fed (30-30 types), or a machine gun. Other wise it's generally unnecessary, and is similar to fixing something that's not broken in the first place.

GS

 

[GLOOB]

I have experienced massive setback in a semiauto rifle. But this was with cast bullets with a blunt profile. Further consolation is that the setback rounds didn't make it into the chamber. Roll crimp fixed it. That's the only rifle and bullet combo that I roll crimp for.

I have used the FCD on cannelured 223 ammo. Well, dummy rounds, anyway, for debugging a rifle feed issue. The crimp definitely helps to prevent setback when hand-cycled rounds might repeatedly hit a wall at high speed.