7.62x39 subsonic load data

[Rubberduckie]

I've got a ruger ranch in 7.62x39 and wanna try to load subsonics. I'm not finding any load data or info. I have some russian subs. I know hornady released the sub x. I'm coming up short for my own loads. Anyone have any helpful suggestions on where to find data?

 

[JSH]

I have looked all over as well for data, with zero luck.
I am sure someone will suggest trail boss, pixy dust and all but unobtainable. Another niche powder that came and went.

 

[mgunderson]

Quickload is helpful. I tried several larger caliber pistol Powders. Out to 100 yards you should have several options.

 

[Oso]

Simple answer is go look up 300BO subsonic load data. Approximately same bullet diameter, with only issue being 7.62x39's limited selection of heavy bullet typically used for subsonic loads. In AR platform need the heavy weight bullets to offset the reduced velocity in order to generate enough force to properly cycle the bolt carrier group. I assume that you may have similar issue for AK47, which might be reason there is limited information on subsonic 7.62x39. If you are loading for a bolt gun then any weight bullet can be subsonic.

Aside from the bullet weight consideration, the other challenge with subsonic is the significant reduction in powder charge. This becomes problematic in larger cases where case fill becomes an issue. The additional case capacity of 7.62x39 over 300BO might cause an issue with the small volume of powder (9-10gr) similar to what happens in loading subs for .308 Win. The excess case capacity creates an issue of inconsistent ignition/performance as small powder volume is spread all over bottom of case or may collect at on end or other of case depending on how the cartridge is handled before firing it. The most popular solution is to use a bulky powder, such as TrailBoss, to reduce the amount of empty space inside the case. Others have also added some form of packing/stuffing to keep powder pressed around the primer hole to ensure a more consistent ignition.

Good luck

 

[rls2184]

I went down the 7.62x39 subsonic rabbit hole last year. I ended up with 11.9 grains of CFE BLK using a 245 grain cast Missouri bullet. This load works great in my 10.5" AR. For some reason it will not cycle my son in laws AR.

 

[MYK]

I went down the 7.62x39 subsonic rabbit hole last year. I ended up with 11.9 grains of CFE BLK using a 245 grain cast Missouri bullet. This load works great in my 10.5" AR. For some reason it will not cycle my son in laws AR.

I'm trying for 7.62x39 subsonic, with no success so far, but your post is most encouraging!!!
The 245 grain cast bullet from Missouri Bullet is .309 Did you shoot it "as is" or did you resize it to .311? What's the barrel twist on your 10.5" AR?

 

[Ledd Slinger]

Would definitely recommend getting an adjustable gas block. I think they make them for the ranch rifle…

Nice thing about ARs is you can install an adjustable gas block to tune it where it cycles reliably and doesnt run too hot with a supressor

 

[Oso]

For what it’s worth, H110 performs better than CFEBlack for subsonic loads in short barrel. Vihtavuori N110 is best (clean burning & accurate). Hodgdon H110 work well for both supers and subsonic, and works great in short barrel length.

Despite the clever marketing name, CFEBlack is a bit underwhelming (slower powder) making it less effective for short barrels.

 

[jsn]

Hodgdon now has subsonic data online.

 

[SD guy]

Yes & Imr 4198 under a 255 gr Sub-x looks encouraging to me

 

[MYK]

The Hodgdon-published data for 255 gr Sub-x with CFE-BLK behind it works fine in AR platform. It does not work in SKS (at least in mine), producing keyholes of varying shape at 50 yards.

What I am after is recreating the experience of rls2184 (post above) with 245 gr cast bullet from Missouri Bullet company. So far, I haven't been able to.