.308" /7.62.39?

[lgm270]

Anybody tried or heard of  necking down the 7.62x39mm  from .311" to .308"? 

Is there any point to do so, other than to have access to greater variety of bullets?

[Mikey]

Igm - nope, not yet heard of that but what the hay, if you shoot your 7.62x39s through a earlier Ruger Mini-30 they spent shells come out that way - necked to 308. 

I don't know that there is any real advantage to necking it down for better bullet weight ranges but I am certain you can get seating/crimping dies and decappers to .308. 

One of our members here condcuted some pretty exhausting tests using 308 bullets in the 7.62x39 and found them to be just about as accurate as .311s - depends on the rifle I guess. 

Also, Shooting Times, I believe, ran a article on using that short Russian round with 308 bullets - pretty interesting. 

It almost does not seem to matter what diameter you use, the case capacity is what really restricts the effective use of heavier (more than 150 gn) bullets in that caliber.  I make a 300 Whisper type load with 12 gns of WW296 and a 180 gn .311 slug that is accurate at 50 yds - haven't tested it further out yet. 

You can always try the 308 slugs for the Tokarev pistol, or the 310 slugs for the 30 Luger or 32 acp, for plinkers and you can go up to the 110s for the 30 carbine or 308/06 varmit loads and see how they shoot in your rifles(s). 

Actually, depending on your particular set of dies you may already be getting close enough to .308 diameters to just try switching them..HTH

[lgm270]

Good points all Mickey.  I saw a .308/7.62x39 on a  chambering list for one of the smiths who do TC Contender work.  It was either SKS or Bullberry.  Just wondered if it ever took off.   BAck then there were not many good .310" or .311" bullets available. Now there are many.

[R.W.Dale]

I've gone .002" both ways on this and any way you slice it EVEN TODAY your .308" bullet selection and quality is far superior to .310/.311

Your mileage may vary but I've found that amongst my guns with .310 bores that .308" bullets shot fine as did .310" bullets in my .308 barreled rifle

It almost does not seem to matter what diameter you use, the case capacity is what really restricts the effective use of heavier (more than 150 gn) bullets in that caliber.

I agree wit the caveat that your bullet selection is the bigger problem here too.  150 to 180g bullets in .310"+ are all intended for 303/7.7mm impact velocities and will not expand reliably at x39 speeds. But 7.62x39 has no problem getting 150 or 170grn 30-30 projectiles going fast enough to do their thing. You just gotta use the right projectile

[roper]

lgm270, I guess I misunderstood your other post going from .308 to 7.62x39 I figure you wanted to neck the case to 308.

The rifle I did using the 7.62x39 case was necked up to 30 cal used a 30 cal 1/18 twist barrel shooting BIB 30 cal 112/118gr bullets.  Here their site http://www.bibullets.com/products/

Randy the owner of BIB bullets was the driving force behind the 30BR.  Before the 30BR I was shooting the 30x44/30x47 and 30IHMSA for the hunter class in HBR matches.  Here the rules "HUNTER CLASS: A 10 pound rifle; any cartridge with no less than 30-30 case capacity (45 grains of water); any sights, scopes must be 6X or less (variables must be set and taped); rebarrelling, restocking, and special triggers permitted. (See Rule Book Article 2 and 3)  yardage is 100/200/300yds most matches only go to 200yds

When they started making 1/16 to 1/18 twist 30 cal barrels that open the door to the 112/118/125gr bullets and that is one reason I did the 30 cal on 7.62x39 case.  I used that rifle as a pratice rifle was very accurate.

Now a history lesson.  If you want to make 7.62x39 you use the 220 Russian Sako case.  Before the 220 laupa case hit the market we use that 220 Russian Sako case to form cases the 6ppc case when that market dried up I and many others use the 7.62x39 case to form 6ppc case some even took the Rem Br case tuned  down the rim some even used the Sako ppc case.  Nobody want to admit it but alot of matches using the 6ppc back then were won with some odd ball cases and the 220 Russian Sako/220 Laupa case on their own are pretty accurate.  The 7.63x39 has Water cap in gr @33.98 and 6ppc @33.80.

I build that rifle as a 30cal so that the only thing I can comment on.   They use to make a mini-mauser in 7.62x39 caliber I took that rifle and had it  redone over to the 6ppc was one of the first repeater action for the ppc case Hart did all the work on that rifle.  Ruger did and still does chamber for the 7.62x39m that one reason they made a limited run of repeater action chamber for the 22/6ppc and I think Sako made some also.