6.8 SPC Forums banner
  • Hey Guest, it looks like you haven't made your first post yet. Until you make an introduction thread, the rest of the site is locked to posting. Why not take a few minutes to say hi!

Sub Load developement

1298 Views 7 Replies 5 Participants Last post by  joshuades
I finally got to shoot my subs yesterday. The 135gr smk were sooper quiet with no ballistic crack. It sounded quieter than a nail gun through my aac 7.62sd. I expected this to work as a few guys on here already tried this, but the exciting thing is......

I shot the 150gr gameking successfully. I just wanted to try it. Man they do some damage even at the slower speed.
150gr SGK
10.8gr RL7
COL 2.29(this is the smallest you can go. This puts the ogive right at the case mouth.)
Stag 1:10 SPCII(carbine gas)
They stabilized at 50yd and really did a number on the wood and tree my target was attached to. I shot two of every charge without the suppressor to verify they would work and then put it on. I was very pleased with not only the sound(quieter than a nail gun), but the way they performed on the wood. I am going to try some more at 100yd now that I know they won't damage my can. I have a funny feeling that there won't be pretty nice little holes at 100. I felt like they were barely stable and wanted to tumble as soon as external forces were applied. They might work well for close soft tissue targets. This load ejected with the can attached, but the bolt wouldn't come back far enough to grab the next round. Any ideas to make it feed? I would like to make it feed as the action noise was the loudest thing I heard from the weapon. Accuracy was good, 4 shot groups touching at 50yd. Definitely not hearing safe with my normal loads as expected. I'll post results(with chrono data, which I didn't have this time) as soon as I shoot at 100yd which will really tell if this is worth persuing or not.
See less See more
1 - 3 of 8 Posts
Great info. thanks for posting it.

I have yet to try the 150 grainers yet, as my 1: 9.5 barrel isn't here yet. I bought an old M1S barrel off a guy to see if I could get some 150's to cycle. I will definitely try these.

I am going to load mine out to 2.30". There are only 3-4 other ways to help improve cycling:

1) Cut a few coils off your spring.

2) get a lightweight carrier from Young

3) drill holes in your buffer to lighten it up

4) drill out the gas port to a larger size
See less See more
Would an adjustable gas block help out if you went the #4 route? Then you could choose between a setting to allow for cycling with sub loads, and one that would be bolt-gun quiet. And then you have the "normal" settings for when the can is off and you have normal loads.

Sounds like a non-issue for you if the sub-loads don't work at 100 yards, but I've been curious. Once I bite the bullet and get into rolling my own, I know it will be a real slippery slope to making sub loads, then a suppressor...sounds like you know exactly what I mean.
that is exactly what I use. then, I tune my gas to whatever the purpose. I can make the brass eject perfectly for the hottest loads, or turn it off altogether for the greatest stealth.
I think I'll go the adjustable gb way. It makes the most sense. My brass was landing right at the 3 O'clock position smoothly ejecting, but never grabbed a subsequent round once out of 20rnds from 10.8gr up to 11.4gr(which was completely super sonic). I don't want change how she runs right now as my quiet shooting is only a hobby, and normal shooting is bread and butter for pigs and deer. So I should not have to mess with the buffer or spring at all if I open up the gas port a little and install an adjustable gb then tune right?
That is the hope. Ths SAAMI leade increas pressure, so if you had a SAAMI chamber, you might get cycling without having to do that.

There are other powders which might also give you complee cycling without having to drill out the gas port. You might try Accurate # 9.
1 - 3 of 8 Posts