7.62X54 Question about bullet replacement in Mil Surplus rounds...

[vintage hunter]

Yep, it is right up there.....311" (slug size) so I think a .308 bullet would fit mighty loose...sorta wobble down the barrel...

That all depends on bore dimensions and condition I reckon. It's been my experience that Finnish built Mosins and German made Argentine Mausers usually shoot just as well with .308'' bullets as they do with the 311/312's. The bores of Russian and Argentine made barrels can vary widely, groove diameters as large as .316'' have been reported in MN's and .314'' in Mausers made by the Argentines. Like WarPig I can't comment on the SVT's but doubt they'd be any more consistent.

The problem I am running into is finding a bullet in the .311" size

As said above you have to look for 303/7.7mm to find them. Had a quick look on the Grafs, Midway and Natchez websites and they're all are showing a variety of 311/312 150gr bullets in stock.

[Parashooter]

. . . If one slugs a Mosin Nagant bore he will find a bore diameter of .312 or more.!!! . . .

Not exactly. While .312" or more is likely to be the groove diameter, the bore diameter is normally closer to .300" as stated by Bruce_in_Oz earlier.



Those interested in selecting bullet diameters for accuracy might find this article useful -

[WarPig1976]

Ok you caught a typo, nice graphic though.

[jmoore]

Excellent article referenced by Parashooter.

[WarPig1976]

Would have been interesting to see a side by side comparison using a barrel that shot A,B,C flat based bullets.

[jrapose]

Thanks ! I had not thought about looking at .303 bullets.... and will try the Midway 150g bullets... I wonder why they only list that bullet for 7.62 X 39 instead of 7.62 X 54r ??

I think that is the answer to my troubles.... I am a bit shy about putting a lighter or heavier bullet in without knowing what the powder is...

Joel

[Bruce_in_Oz]

Odd that Midway would list the 150gn job for 7.62 x 39.

Most bullets for that cartridge run 124 to 130gn to achieve working muzzle velocity and port pressure.

If they have a stock of 150gn .310 (ish) bullets at the "right price", grab a swag and play with them. If you are not entirely satisfied, you can easily off-load them to folks shooting 7.62 x 54R, .303, 7.65 Argy / Belgian, 7.7Jap etc.

[WarPig1976]

Odd that Midway would list the 150gn job for 7.62 x 39.

There are a few bolt guns that use the round. The CZ 527 is at least one I know of.

[Bruce_in_Oz]

The problem with "heavy" bullets in little cases is that, particularly for hunting, the down-range performance of any given bullet is dependent on "terminal velocity" to achieve the right balance of penetration and expansion.

The relatively small 7.62 x 39 case just does not have enough capacity to launch a bullet that is much heavier than the original, at a velocity that will deliver the full potential of the bullet down range.

If your magazine will not allow seating out of a longer, heavier bullet, you are effectively wasting powder space, and there isn't much spare in this compact cartridge.

Furthermore, most .303 / .311 bullets in the 150gn range are built to be launched by .303 class cartridges, and thus have fairly "robust" jackets.

HOWEVER, if you want to go the other way and play in the field with the .300 Whisper, the twist rate (1:10") is too SLOW for "big", eg. 220gn. bullets launched at such low velocities. .300 Whisper / Blackout runs in 1:7" twist, just to stabilize the long bullets at low speed.

I have heard of folks splitting the difference and using 170-180 gn FLAT nose bullets designed for the .30-30 etc. These are relatively short for weight, have thinner jackets and are designed to "perform" at .30-30 velocities. How they perform on game at subsonic velocities is unknown to me.

How they feed from various mag. systems is subject to experimentation.

Have at it!

[WarPig1976]

This article repeats your information Bruce. They say all bullet weights gave good results until 160g bullets started to show some yawing.

Reloading the 7.62x39 - Guns Ammo

I think that is the answer to my troubles.... I am a bit shy about putting a lighter or heavier bullet in without knowing what the powder is...

Shouldn't be a problem with 150g bullets. Get an average charge weight and reduce it by one "1" grain if it makes you feel better. Just make sure the rifle will cycle with a reduced charge.