Is there any room for improvement for 7.62x39

[GIJOEL]

Has anyone squeaked any more velocity out of the 7.62x39? It seems that for a cartridge that has been around for so long there would have been some improvements in performance. With Hornady and Sierra both making bullets for the 7.62x39 I would think someone out there has gotten those bullets to higher velocities. For that matter, what is the consensus on the best powder? Best loads for deer? Also is anyone aware of a company making bullets with boat tails for the 7.62x39? I know that Golden Tiger is loaded with at Bi-metal fmjbt.

 

[rbernie]

The only way to get higher velocities is to run higher pressures, which in turn runs afoul of gun life and safety. You are dealing with a case with very limited powder capacity; there is only so much that you can reasonably expect from the round.

More to the point, the 7.62x39 was invented specifically to be an intermediate round , one that has less ooomph (but also a lot less recoil) than a full power round. In trying to hot rod it, you ruin the principal trait of the round....

 

[R.W.Dale]

What you propose simply isn't feasible in current autoloading 7.62 platforms. Some fans can be made through bullet selection, but not in the fps dpt

 

[ScratchnDent]

I can barely match factory velocities with any of the canister powders I've tried. Just not enough room in the case for powder. What has improved for me is accuracy/consistency. Hogs don't seem to care that the bullet is going 100 fps slower when it hits them where I aimed, rather than 3 inches to the right.

ETA: I've settled on H-322 with a .310 125 gr. Remington SP as my gun seems to like that combo.

 

[rfwobbly]

Exactly. IMHO there's more to be gained from getting the barrel/bullet fit right than higher speeds.

 

[Kernel]

Velocity is over rated. Accuracy is where it's at.

 

[GIJOEL]

Thats what I figured, then what bullet for deer? Sierra spire point? Hornady V-max? my barrel slugged at .310 so I'm a little limited on choice. Are the solid copper bullets worth there price?

 

[Afy]

In terms of powders N-120 seems to work well for me, as does SP-10.
GIJoel I dont think a deer will notice the difference between the normal bullets and a solid copper bullet.

 

[rbernie]

Hornady and Sierra make .3105/.311 123gr or 125gr bullets, and either will work. The Sierra is stouter (suitable for heavier deer and/or closer ranges) while the Hornady is 'softer' and is more suitable for smaller deer and/or further ranges.

I have used both with success, altho the Hornady is probably more suited to the itty bitty Texas deer. In the past, I tended to run the Sierra 125gr bullet, just because I was willing to sacrifice a bit of immediate expansion for the ability to punch through the errant hog that I might run across in my path. Right now, my deer loads use the Hornady.

You can use the .308 class bullets, with some minor caveats. I do not, because I've never seen a need to do so. Lee even makes a .308 decapper pin for their 7.62x39 die set.

 

[kludge]

A-1680. Developed specifically for the 7.62x39.

I have not used this round on deer (illegal in Indiana), but I would choose Hornady bullets if I did.

 

[bfoosh006]

While the comparision of these two cartridges isn't "apple to apple" the 30 AR is probably as "improved " as you could get out of that sized cartridge...I wonder if you could change an AK to be able to tolerate the 30 AR cartridge.

I know the 30 AR isn't the right size (.311 v. .308 ) and it isn't tapered for the AK magazines, ...but if you could buy a 30 AR chambered AK ...I might just consider it....

 

[GIJOEL]

Actually I'm on the other side of that equation, 7.62x39 AR. I like the idea of .30 AR, but it's a wildcat, honestly I like the 6.5 Grendel the best but the prices for ammo to start generating brass are just too high for me.

 

[R.W.Dale]

If your gun will shoot it well the high BC per weight of 125g nosler ballistic tip can provide a pretty significant boost of power and trajectory at range.

It's the bullet I used through my x39 ar to harvest a doe at over 270yds

 

[armoredman]

I am trying to come up with a great cast bullet load for mine, right now, and that's a lot of fun, too.

 

[kludge]

I've gone down the .30 AR route looking for a deer legal wildcat cartridge for Indiana.

There is NO brass available, and barely any ammo. (I have a couple boxes if anyone wants to buy it.)

Remington changed the case head (not like the .284 parent case anymore) to an obscure size, so a normal .308 bolt face won't work. This was to prevent death of some idiot who tried to put a 60kpsi round in an AR-15. The uppers are only sold by one company right now that I can find.

I don't think the AK could handle 60kpsi either.

 

[frankge]

IMHO its bullet selection. I use the VMax and it gets me a tad more velocity and a lot more accuracy - even in my AK. I also am loading 147 steel core FMJBT and there are very accurate compared to the russian animal ammo out there. I do this more for fun that seriously trying to match my AK a match rifle. I think the key is .310-.311 bullets. Powders - AA1680 and RL7 for the heavier 147's

 

[Clark]

I could see that the Remington case heads for the SKS are small primer and stronger than the Win case heads that are large primer.

I bought up all the Rem brass I could after they stopped making it.
I divulged why I wanted it, and maybe that contributed to other's trying to buy it up too. I had a hard time getting it.

I got someone to do the calculation for me.

Clark,
Here are the results of the von Mises stress calculations for ..case head.
Using mechanical properties for C26000 brass (cartridge brass)
Temper - H06
Tensile yield strength - 65,300 psi

The 7.62X39 Soviet case head nominal condition chamber pressure for the initiation of case head yielding with H06 C26000 brass AND LARGE RIFLE PRIMER is: 66,769 psi
The 7.62X39 Soviet case head nominal condition chamber pressure for the initiation of case head yielding with H06 C26000 brass AND SMALL RIFLE PRIMER is: 81,609 psi

But my tests of the two types of brass are inconclusive, as my test rifles, SKSs, are junk.

If I ever buy or build a 7.62x39mm rifle that is more sturdy, I could test.
Right now I do not have the reamer and I do not have plans.

 

[R.W.Dale]

this pic I did a couple years ago reflects my testing of lapua 7.62x39 cases compared to small primed rem as far as expansion just above the case head using AAa1680 in a custmom 7.62x39 stevens 200

the pic doesn't do a great job of showing the difference in expansion but the measurements are pretty conclusive