200 grain 7.62x39

[mctrigger]

Doing some thinking.

I have a CZ 527 in 7.62x39 it shoots 123 SST just great with AA1680, but I’m curious to try some D166 Lapuas in her. 200 grain .310 FMJ that I use in my 54r.

Looking at lapua data they run 200 grain .308 that shares similar profile bullet over N120/130

Just wondering if anyone has run heavy bullets out of a x39?
I’m sitting on some H322 that possibly could work.

 

[bearhunter]

Check the twist rate of your bore first. It may be too slow to stabilize the longer bullets. If the twist rate is the usual 1-9 it should be ok at subsonic speeds.

I used to shoot cast lead 210 grain bullets out of my CZ, using 2400 powder, I started with 12 grains over standard LR primers and got around 900fps with the load I settled on. It was quite accurate at 100yds, so I tried some .308 diameter bullets and started at the same 12 grains of 2400.

Accuracy wasn't as good as with the cast lead bullets, which measured out at .312. Pressures built up faster as well.

I didn't pursue this, but opted for 150 grain bullets instead, with 31 grains of W748 over CCI 250 primers, only because my supply of 200 grain bullets was lacking.

The action is strong enough for a substantial load but most of the folks who have played with such heavy bullets, that I've talked to, were looking for subsonic performance.

 

[4fifty8]

Hornady .308 180gr RN in my 7.62x39 Ruger No.1 @ 2175 fps mv. Could do 200gr likely around 2000+ fps mv. Got freebore length to seat bullets way out for maximum case capacity as well as action strength to handle higher pressure. Not H322 but that should also work in my rifle.

 

[mctrigger]

Subsonic performance is good. This is only for Interest and has no real purpose out side of fun.

 

[hoytcanon]

I would only shoot 200's if I was trying for a sub-sonic load. The little 7.62X39 case maximizes it's performance with 150 grain bullets.

 

[saskgunowner101]

Subsonic performance is good. This is only for Interest and has no real purpose out side of fun.

I'm curious to see how this turns out. Have you run any numbers with the greenhill formula to see if you have some wiggle room stability wise if you run them a bit slower than 4fifty8 mentions?

 

[70m4h4wk]

If you haven't already, look into the 7.62 Thumper.

It's a 7.62x39 that uses a .308 barrel instead of .311, with a 1:8 or faster twist for running 240gr bullets like SMK or woodleigh.

Those guys should have all the info you need

 

[legi0n]

https://www.reddit.com/r/reloading/comments/imt1c5/230_grain_762x39_part_2_results_and_success

 

[B]

^I have the LEE 230grn mold as well as a 245 grn mold, bought for .300BLK but have yet to do a significant amount of casting with it. Loading for x39 is on the list as well. Nice to see someone has already been there with some success.

 

[Andy]

Some info here: https://www.canadiangunnutz.com/for...llets-in-their-7-62x39.1682258/#post-14615935

I've gone as heavy as a 247 gr cast bullet over 4.0 grs of Red Dot for 725 fps. That's a light load.

 

[sard]

I shoot 170 grain cast bullets sized to .312 at 1850 FPS out of a CZ527. It's accurate, having said that 30 grains is a big difference.

 

[mctrigger]

I shoot 170 grain cast bullets sized to .312 at 1850 FPS out of a CZ527. It's accurate, having said that 30 grains is a big difference.

What powder.

 

[sard]

What powder.

IMR4198. It works the best out of everything I've tried for this cartridge.