extraction difficulties

[thl]

I can't figure out why this is happening. Whenever I try to eject an unfired round I have significant resistance. Recently I have had frequent failures to extract and have to ram the butt of the gun on the ground while pushing on the charging handle to clear it. I am using a RRA Predator Pursuit upper (Wylde chamber I believe). Brass is mixed, mostly Lake City and the problem is not brass specific. Bullets are 69 SMK's and 55 Prvi Partizan over 23.8 and 23.5 H335 respectively. Case trim length is 1.745. Cartridge OAL is well below mag length. I am using a Dillon RL 550 with small base RCBS (full length) X-dies. I initially size the brass with a Dillon small base die on a single stage press before the initial trimming. Resizing dies are set up per Dillon instructions. I have checked the cartridges with a JP case gauge which supposedly is tighter for match barrels/semi auto's and they are not tight at all and fit flush. I have checked the ammo in another rifle with a 5.56 chamber and extraction is difficult in it as well. I have made sure the chamber is clean. I haven't changed anything in my reloads and have not had functioning problems in the past although I have always noted difficult manual extraction of live rounds in the RRA with the Wylde chamber.

Edited December 19, 2010 by thl

[RiggerJJ]

Usually with this problem you need to look at 3 places;

1. Body sizing (too tight)

2. Shoulder expansion (too tight)

3. bullet under-seated (stuck in rifling, different bullet's ogive can give you fits)

try coating a round with black magic marker and let it dry, chamber it by dropping the bolt on it, then extract it. check it over carefully to see if you can find the sticking point(s).

jj

my guess is your sizing die needs to be set just a bit lower...

[thl]

Usually with this problem you need to look at 3 places;

1. Body sizing (too tight)

2. Shoulder expansion (too tight)

3. bullet under-seated (stuck in rifling, different bullet's ogive can give you fits)

try coating a round with black magic marker and let it dry, chamber it by dropping the bolt on it, then extract it. check it over carefully to see if you can find the sticking point(s).

jj

my guess is your sizing die needs to be set just a bit lower...

I marked up a cartidge with a sharpie and its scuffing at the base of the shoulder so I think you are right. I'll have to see if I can move the die down anymore. A guy I shoot with had similar problems and had to mill the base of the die down a few thousandths to fix it. Hopefully I don't have to go this route.

Thanks

[RiggerJJ]

drop the die head down to the shell plate WITHOUT a case in the die. screw the die down to the shell plate and tighten the die nut, and try it.

If that doesn't work, raise the head, and turn the die down another 1/4-1/2 turn towards the shellplate. (this is called over-caming) I had to do this with my 223 die...

jj

let us know if it worked

[AustinT]

You need to trim to 1.730 the first time before using an x-die. Are your cases still short enough?

I would bet that you need to screw your sizing die down a bit more.

[RBros]

The only brass I had stick in my predator pursuit was some older milspec stuff we had lying around. Used a small base die and bump the shoulder a bit more and the problem went away. I haven't experienced any of those problems using Scharch processed brass. I would say to run the die down a bit more and try that and see if it helps. I didn't even come close to the land in my rifle when loading it to mag length.

[mlmiller1]

I took a belt sander to the base of my resizing die, but only for a few seconds, not very long at all. Worked perfectly then. I think my dies are lees, if I remember right. Anyway, I only took off a very few thousandths but didn't have to do it at a mill(which I don't have). Before then, even overcamming wouldn't quite get the shoulder far enough back. Now, no problems.

MLM

[thl]

drop the die head down to the shell plate WITHOUT a case in the die. screw the die down to the shell plate and tighten the die nut, and try it.

If that doesn't work, raise the head, and turn the die down another 1/4-1/2 turn towards the shellplate. (this is called over-caming) I had to do this with my 223 die...

jj

let us know if it worked

Moved the die down a 1/4 turn past contact with shellplate to cam over. Haven't fired any more loaded ammo but made a few dummy rounds which chamber and extract without any difficulty so I think the problem has been identified.

Thanks for the help,

TL

Edited December 23, 2010 by thl

[RiggerJJ]

KEWWLLL!!!

[Mike Morcillo]

Chamber may be dirty. Run a chamber brush to clean it up. Make sure your brass it trimmed to 1.750. Bullet may be touching the lands and grooves due to too long OAL of cartridge. Use a case guage to check each piece of brass for spec.

Edited January 20, 2011 by Mike Morcillo