AR15's and bullet setback with no crimp

[dmftoy1]

I know this has been hashed back and forth but I thought I'd share my experiences from yesterday. My next door neighbor was trying to dial in his AR (Bushmaster Varminteer) and had brought an assortment of ammo. He had no problems with XM193, Black Hills, Federal American Eagle and WWB, but in switching to loads from the local bulk loader he had some bullet setback. The setback was occurring in both the "new" ammunition (all components) and in the reloads. He had 60 grain a-max, 77 grain sierra's, and 68 grain SMK's. It happened in ALL of the loads from this guy. Seemed to be about every other round. I happened to catch a jam after he had been shooting for awhile and asked him to show me the round (one is pictured below) he said that he had been experiencing it pretty regularly with the rounds and had shot a bunch the day before. (I told him I would NOT shoot any more of these)

What do you guys think? Could this much bullet setback cause an overpressure and kaboom? I'm kicking myself for not asking him to chamber a round by dropping the bolt and then ejecting it . . .I suspect they were all setback.

 

[Evenflo76]

Uh, this guy was firing rounds that looked like that?

 

[30Cal]

Shouldn't be happening. The most you should see is about 0.010" tops.

Someone's expander ball (sizing die) is waaay too big.

 

[dmftoy1]

Yeah, I told him he should get ahold of the guy as something is seriously out of spec. He even had some rounds in brand new Lapua brass that were doing that. The guy who is doing the loads has been at all the gunshows in a 100 mile radius for probably the last 15 years or so . . .he usually takes 3-4 8 foot tables on each side and two on the ends covered with reloads.

 

[snuffy]

The guy who is doing the loads has been at all the gunshows in a 100 mile radius for probably the last 15 years or so . . .he usually takes 3-4 8 foot tables on each side and two on the ends covered with reloads.

That, right there, is why he has problems. He does so much loading, he don't take time to do quality control checks.

Either his sizer die is worn out, or his expander is too big. Neck tension just isn't enough! And no, a crimp die will not help either.

 

[matrem]

THE biggest difference (other than the obvious seating "experimentation") that I discovered when first loading for AR (.223 ),was that the expander balls on the two dies that I own,were too big to hinder "setback".After using emory cloth to remove about 15/10000 from my(now) AR die,have had no more problems.

 

[jmorris]

I'm kicking myself for not asking him to chamber a round by dropping the bolt and then ejecting it

That would have been a hoot, filling the receiver with gun powder and sticking the bullet in the barrel.

This is why folks say don’t shoot reloads of others.

If you are using the ammo for autos the bullet should have a cannelure along with a decent crimp.

 

[K3]

That would have been a hoot, filling the receiver with gun powder and sticking the bullet in the barrel.

This is why folks say don’t shoot reloads of others.

If you are using the ammo for autos the bullet should have a cannelure along with a decent crimp.

I'd agree with A and B.

C - No.

168gr Matchkings over 4895 are a proven load in m14 style rifles. No cannelure in those.

I don't crimp for ARs, and I've never had bullet setback. Hornady VMax bullets have no groove, and I'm not seeing the point in crimping into a bullet that doesn't have a groove.

 

[W.E.G.]

After using emory cloth to remove about 15/10000 from my(now) AR die,have had no more problems.

I think you meant to say EXPANDER BALL - not "die."

 

[matrem]

Yes Sir, You are correct.

 

[SSN Vet]

I'll take one LFCD please.....