9x39 powder options and load data

[mattri]

Thanks for the update- look forward to watching the progress of this project.

 

[Raccoon]

You mentioned on another thread that you might try Accurate 1680 for 9x39. Would love to see that data if you try it since it's one of the few powders that I have right now.

Correct, I actually found some the other day. I'm almost done working with Lilgun. A1680 is next.

 

[Raccoon]

I found Vihtavuori Powders at sub velocities burn fairly clean.

9x39mm Ruski.
286 gr Hornady SP Interlock
10" to 16" bbl subsonic.

7.5 gr N-340
8.0 gr gr N-350
8.0 gr N-3N37
8.5 gr N-3N38
8.5 gr N-105

I've also been looking for some N series powders. I've noticed CFE BLK is not fully burning in the 10.5 barrel. I'm fairly close to case capacity with it.

 

[Raccoon]

Thank you for the merge.

A 1680 is next for a workup.

 

[Growler215]

Finally got to the range today to continue my load workup for my 9x39 AR pistol (8.5 inch Tactical Kinetics barrel). Using brass formed from Starline Grendel Basic brass, annealed and sized using the Redding Wolf die and trimmed to 1.514 in., Hornady 286 gr Interlock bullets, CCI #41 primers and Lil' Gun powder. OAL was 2.190 in. Temp was 92F at the range.

Results:

13.0 gr - 956 fps, s.d.35 fps, 2.9" group
13.2 gr - 988 fps, s.d. 7 fps, 1.6" group
13.4 gr - 1019 fps, s.d. 11 fps, 0.7" group
13.6 gr - 1044 fps, s.d. 10 fps, 1.4" group
13.8 gr - 1070 fps, s.d. 20 fps, 0.7" group

Best groups were 0.7 inches with 13.4 gr and 13.8 gr (25 yds with red dot sight). Other loads with decent SD's (13.2 and 13.6 gr) seemed to fall where the point of impact was transitioning, i.e. some rounds near previous poi and some near new poi.

Anyway, I now have, finally, 2 apparently equally accurate 9x39 loads of 1000 fps + for the 286 gr Interlock bullets. At least when it's 92 freaking degrees outside. . .

As a test, I also fired a single 9x39 loaded with a 286 gr Barnes TSX in front of 10.0 gr of Lil' Gun. Those solid copper bullets are way long (and thus sit very deep in the case), so I wanted to start pretty low but hopefully high enough to avoid sticking a bullet in the barrel. It left the barrel, at 699 fps. So now I can start working up a load for these bullets. At least I should have better case fill with Lil' Gun. . .

 

[Raccoon]

I've been working with SRP 6.5 Grendel brass and the MBC 275 grain with good results.

I believe I've found a crimp die as well. I'm currently working with a Lee factory crimp die in 357 SIG.

 

[Growler215]

I've been working with SRP 6.5 Grendel brass and the MBC 275 grain with good results.

I believe I've found a crimp die as well. I'm currently working with a Lee factory crimp die in 357 SIG.

For crimping non-canelure bullets like the 275 gr MBC and the 270 gr Speer HotCors, I just ordered a Lee Custom Factory Crimp Die in 366 TKM, which they have in stock as overruns. The 366 TKM is a weird round; it's based on a tapered 7.62x39 with no bottle neck. Apparently the Ruskis have been using it in smoothbore muskets for hunting since civilians over there have a hard time getting permission to own a rifle (no surprise.)

Also FYI, KAK has factory Starline 9x39 brass back in stock. Its LRP though. Interested in finding out if LRP will reduce my SD when case fill is less than ideal so I ordered some. So far I've avoided using any filler material...

I loaded up some of the 275 gr MBC's (5 ea 14.0, 13.8, 13.6, 13.4 and 13.2 gr Lil' Gun) with SRP brass but haven't got to the range to test them yet...hopefully next week. Had some issues with getting them to the same COAL with the Redding seating die.

 

[Growler215]

I loaded up some of the 275 gr MBC's (5 ea 14.0, 13.8, 13.6, 13.4 and 13.2 gr Lil' Gun) with SRP brass but haven't got to the range to test them yet...hopefully next week. Had some issues with getting them to the same COAL with the Redding seating die.

Finally made it to the range to test my 275 gr MBC loads. First I had to reconfigure my 8.5" 9x39 AR pistol to comply with the new ATF brace regs.

I live in Maryland so also have to comply with their laws, one of which is that a rifle can't be shorter than 29" (measured with stock extended.) With an 8.5" barrel AR, no way to get to 29" so no way to SBR this pistol in MD. So I put a pistol buffer tube and SB-Mini brace on it. ATF's "Factoring Criteria" says this is a legal AR pistol configuration as long as it doesn't also have a scope or vertical foregrip.

While I was at it I also dremelled the M4 feed ramps to create a single feed ramp and polished it up nicely.

Finally, range results:
8.5" Tactical Kinetics barrel AR, pistol length gas system, Starline SRP brass, CCI #41 SRP, Lil' Gun powder, 275 gr MBC FP-GL .366 bullets, 2.031 COAL, 25 yds, 5 shot groups, 66°F.

Ch wt. Velocity. Std Dev. Group
14.0 1131. 21.3 >3"
13.8 1123. 19.2 >3"
13.6 1098. 26.5 >3"
13.4 1087. 24.6 2.75"
13.2 1077. 17.0 1.5"

All loads cycled and locked back when empty. Pistol configured with std carbine spring, 1 oz buffer (all wts removed), full auto bolt carrier. No suppressor yet, just a KAK flash can. The non-adjustable pistol buffer tube leads to a Nose To Charging Handle hold and, with the smaller rear surface area of the SB-Mini brace, felt recoil was a bit snappier than with the previous SBA4. Not at all bad, just a bit more.

Next step will be to try 13.0 and 12.8 gr to get the velocity down a bit more. Hopefully the group size and SD will keep decreasing as well. May also try sorting the MBC bullets by bearing surface area, as I read a report from another 9x39 enthusiast that that helped his accuracy.

May also try comparing SDs with and without a tiny bit of cotton ball material to hold the powder at the bottom, as well as comparing SDs with Starline SRP and LRP brass.