.311 bullets in a 308

[mexrunner]

was curious since some guys are running tight bore barrels i noticed sierra makes a 174 gr mk in .311 dia for 303 british would this work similar to running a tight bore ran it in quick load and seemed to bump pressure up but not to much
just curious adam

 

[Sig685]

Re: .311 bullets in a 308

Why look for trouble?

 

[Grump]

Re: .311 bullets in a 308

I've only heard that the .311 in a .308 bore works okay so long as it is loaded to not spike pressures, but tends to foul the throat a bit more.

Never experimented with it in any systematic way, though *lead* bullets shoot okay up to .003 oversize, IME. That's with and without gas checks.

Not sure how much it changes things going from a .0005 or .001 interference fit, to a full .003. Engraving the rifling AND groove that deeply might even facilitate getting the bullet started off-axis, if the chamber and neck are too sloppy.

I leave it in the "emergency field expedients" bag of tricks.

 

[Greg Langelius *]

Re: .311 bullets in a 308

The standard for .308/.311 bullets in the 7.62x39 has been that foreign ammo and bores are nominally .311, and domestic ammo and bores are nominally .308 with 'forcing cone' throat designs so larger diameters can be better accomodated.

There is always some leeway, and that leeway is fraught with the dangers of overpressures. Use your head wisely, your components even more wisely, and test, don't assume.

Greg

 

[ChrisGarrett]

Re: .311 bullets in a 308

Some of the European bullet makers like to size up .001", such as Lapua who has made .309" and .339" bullets. They feel that that extra .001" creates a better seal, but who knows?

I don't think I'd go up .003" personally, but it's your face as they say!

Chris

 

[bohem]

Re: .311 bullets in a 308

I have accidentally done it, and it was plainly obvious as soon as I shot it. The errant bullet was from a pair of .311 tips that I didn't measure, assumed they were 308 and tossed them in the bucket with the other mil-surp 175 FMJ's that I had.

The rounds were already hot, when I ran that through it I got sprayed with a pierced primer and had to tap the bolt up with a rubber mallet.

If you download the rounds and work up you can shoot them, but don't just load them up and go.

 

[Victor N TN]

Re: .311 bullets in a 308

About 25 years ago I had the privilege of working every day with a man that had started hand loading just after WW2. He was at one time nominated for the NRA Board of Directors. He had traveled around the US visiting ammo and gun factories. I brought this same subject up one day and he slapped my in the head with his hat. He asked me, “Haven’t I taught you anything these last years we’ve been working together?” I didn’t ask again.

Like Sig and Greg stated above. “Why look for trouble?”

 

[cinosbus]

Re: .311 bullets in a 308

The longer the bearing length, the higher the pressure is likely to be.

I have shot a few .310" 123gr V-maxes (meant for 7.62x39)that Hornady makes special for Graf & Sons in my .30 Herrett Contender. I can't tell the difference from 125gr .308" NBTs.

Try it, but start 10% under max load and work up. I assume accuracy will not be as good because you are deforming the bullet some by squeezing it down.

FWIW, you can re-size jacketed bullets with the Lee push-through sizers they make for cast bullets. I've done that too. It is easy to make .309" bullets from .311 or .310 that way. It was a wasted step for my Herrett.

 

[mexrunner]

Re: .311 bullets in a 308

thanks for replying just was curious and at least i know in a pinch what i can do if i had to

 

[Graham]

Re: .311 bullets in a 308

In a phrase: Don't do it.

 

[desertrat1979]

Re: .311 bullets in a 308

I would avoid it. No one here wants to read about your newly aquired disability after you do.

 

[former naval person]

Re: .311 bullets in a 308

FWIW...cinosbus is right...you can resize through the push thru Lee sizer...but, what you also do is loosen the jacket on the core which really reduces accuracy.

 

[cinosbus]

Re: .311 bullets in a 308

If it is loosening, I can't tell.

 

[Downzero]

Re: .311 bullets in a 308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">FWIW...cinosbus is right...you can resize through the push thru Lee sizer...but, what you also do is loosen the jacket on the core which really reduces accuracy. </div></div>

Loosening the jacket? Are you under the understanding that something is holding the two together?