7.62 Russian rounds (.311) in a .308 bore?

[mannyrock]

Dear Guys,

    I am posting this question here, because you folks probably know more about 7.62 Russian rounds than anybody else.

    I am interested in getting a single shot rifle in 7.62 x 39mm.   Problem is, the ones made in the U.S. have a .308 bore instead of a .311 bore.

    Now, I know that using the American made 7.62 rounds (with .308 bullets) in a .311 bore give terrible accuracy.  But how about the other way around?   How is the accuracy when you use a European made round (with a .311 bullet) in an American rifle with a .308 bore?   High pressure? Terrible accuracy?

   I am guessing that I would be using Sellier & Bellot ammunition for hunting, and maybe Wolf for plinking.

    All comments are welcome.

Best regards,
Mannyrock

[Bugflipper]

Mannyrock I have heard the same thing. But it is actually incorrect information, but not totally false. A ruger mini thirty, ruger m77, rem 799, and cz-527 are all .310 bores. Also american loaded 7.62x39mm ammo has .310 bullets in them just like the russian stuff, though some is .311. Same thing with the stories that the Vietnamese could fire the 7.62 nato round in their AK. Just folks spreading things without knowing. No big deal. I have loaded .310 bullets in a .308 diameter barrel in a contender pistol (not 7.62x39)and there wasn't any problems. It actually liked the to large in diameter bullet. I can't remember off hand but I believe it was a 30-30 barrel I was shooting .310 out of. They used to have .308 bores and American ammo but all the ones I have seen today are now the .310.

[mannyrock]

Bugfliipper,

   I guess times have changed.  25 years ago when SKS's first became the rage, I saw a friend shooting one from the bench at the gun club.  With the Chinese Norinco ammo, he was easilty getting 2.5 inch grouips at 100 yards.

   When he switched to the new American stuff he had bought (Federal and Winchester soft points), the groups immediatley went to 12 inches and beyond.  Back then, the American stuff was loaded with .308 bullets.

  I guess the American companies finally wised up?

Manny

[gr8ful]

My Ruger Mini-30 has a .308 bore, I bought it in 1991, so I don't know about current production.  I also have 2 boxes left of the original case of remington core-lokt ammo I bought with it in 1991 ($5.95 a box twice as expensive as the russian stuff, but reloadable) just to check I pulled a bullet and it is also .308 cal and weighs 125gr.  Current production ammo may be loaded with correct .311 bullets but it wasn't always so.  My Ruger shoots 110gr hornady.308  over imr4198 to about MOC (Minute of Coyote) at 100yrds but with the wolf brand it is all over the place, My SKS is the opposite It was imported by Norinco and I bought it in a Pawn Shop in 1990.  with homemade hollowpoints (filing 1/8" off the tip of milsurp russian ammo) I killed a couple deer and a nice hog, and was actually the reason I bought the Ruger.  It slings the Core-Locts like Buck Shot.  On a side Note the Wolf Performance 154gr PSP shoots around 2" and is Deadly!

[Bugflipper]

I looked up the load data in my contender book. I was loading .310 win bulk 123 in a 30-30 ai and a 32-20. The 7.62x39 barrel was a .308 bore and I never loaded for it, just bulk russian rounds. There was a fellow on here a few years back that pulled the bullets on current factory american ammo and measured the bores on ruger and cz rifles. All of them were the .310. Most likely it is still cheaper to buy silver bear 7.62x39 ammo than it is to reload. I haven't shot my cz this year but I believe it was somewhere just over an inch with that bulk ammo.

Gr8ful, yours is right on the border line. They changed them in 91. Officially I think they say pre 92 is .308-.311 because they changed in the middle of the year. Post 92 is .311-.310. It is .311 at the chamber and tapers to .310 at the crown according to them.

One of the members here did some extensive testing with .308 hand loads in a .310 bore and got some very good results. Some of his results were terrible as well. I imagine searching 7.62x39 would get you fellow to a lot of info on the subject.

[mannyrock]

Dear Guys,

   Thanks for all of the technical info.  It is great.

    Glad to know that I wasn't dreaming about the original U.S. ammo being loaded with .308 bullets.  Hard to believe that they changed it back in 1992.  I guess I was watching my friend shoot his back in 1989.  Seems like just a few years ago.  (Dang, those 22 years really went by fast!)

   Now, if I could only find a single shot rifle that can shoot the hard primer military rounds, without failing to fire.   

Regards,

Mannyrock

[Bugflipper]

Manny, my contender was not strong enough to fire all of them at first. I had to put in a heavier hammer spring. They did make them in a handi rifle. You may want to ask the fellows on that board if there is any chance of putting a heavier spring on them as well. I never owned a handi in that caliber but a friend had a lot of trouble like you are talking about.

 Not a single shot but the cz will fire the milsurp ammo with dependability. Also not a single but I got a chance to put about 800 rnds through a savage scout rifle and it fired silver bear and wolf without a hitch. It wasn't my rifle. They belonged to the fellows teaching the class. Rossi also makes a single, may want to look into them as well. I have never even seen one of those, but I imagine the handi guys know about them as well.

[quickdtoo]

Now, I know that using the American made 7.62 rounds (with .308 bullets) in a .311 bore give terrible accuracy. 

http://www.gboreloaded.com/forums/index.php/topic,109683.msg1098328568.html#msg1098328568

Check this thread out where I did some testing with a 7.62x39 with various bullet diameters. In short with my .310 barreled CZ527 there is NO diffrencd in group sizes between shootin .308 and .311 diameter bullets.

http://www.gunboards.com/forums/topic.asp?TOPIC_ID=151420

I POSTED THIS PREVIOUSLY ELSEWHERE

It's been pretty hotly contested as to how much diffrence there is between loading 7.62x39 using .308 bullets vs .310-.311 so here it is. I tested this  and here are the results.

The rifle is a CZ527 carbine topped with a 3x9x40 redfield accutrac scope. The bore measures .300 land to land and .3105 in the grooves

The ammo was loaded with 150 gr Sierre soft points 10 rds of .308 and 10 rds of the same bullet sized .311. Cases were Remington CCI 400 , The powder was 23.5grs of Re-7 with a COL of 2.310

It was about 65 degrees today with a light varible breeze of 15 mph

Shot string 1
.308 bullets

1851
1826
1852
1827
1846
***************
Shot string 2
.311 bullets

1935
1904
1937
1912
1925
****************

Shot string 3
.311 bullets

1953
1888 !?
1915
1932
1925
***************

shot string 4
.308 bullets

1852
1855
1869
1844
1873

All velocities were taken at 25 feet.

As you can see there is very little diffrence in group size. About the only real measurable diffrence in using the .308 dia bullets is that they are somewhat slower in the FPS department.

Of course your mileage may vary.