Getting back on the thread topic (
strange thought for this forum, I realize), any folks here that may be considering building an SBR from a Chechpoint (CSA) 762 pistol may be (should be) interested in the superior ballistics of the 7.62x39 (M43) round in short barreled rifles.
...Here are potential untapped strengths of the 7.62x39. First, because of the relatively small powder volume versus bore size, relatively little performance is lost as barrel length is reduced. This makes the 7.62x39 a perfect candidate for very short carbines. For example, a load that replicates M43 using Accurate #1680 powder will lose only about 70 fps when barrel length is reduced from 16 inches to 14 inches. Going down to a 12-inch barrel only loses another 83 fps, while a 10.5 inch barrel will still fire the 123-grain bullet at just over 2100 fps. The 7.62x39 is an ideal cartridge for a short-barreled rifle, provided a bullet that produces good terminal ballistics is used.
Full article here:
http://demigodllc.com/articles/7.62x39-improving-the-military-standard/?p=3Related:
So far I am unimpressed with the sound deadening performance of my new Kestral AK suppressor on the CSA VZ58 11.9" carbine barrel. I have not tried it on a 16" VZ2008 or a VZ2000 yet, which should perform better. My VZ2000 "go-to" rifle, which is equipped with the original Czech chromed-lined barrel, has a Czech muzzle break pinned and welded on it due to Federal SBR laws. The plan is remove the Czech break and to have it replaced and welded with the CNC Warrior barrel extension in order to give me the freedom to swap muzzle attachments and suppressor at will and without violating federal law. Down side and concern of the barrel extension is the loss of the detent locking pin, which I have discovered the suppressor truly requires via empirical testing -- and I have read NOT to use a crush washer with a suppressor. The suppressor starts to unscrew itself off the barrel if you don't tighten it after a few shots. And before I go through pairs of insulated gloves I ordered a Manta cover for it. Any input on this issue would be appreciated.
I will also testing the Kestral on the VZ2008 with various commercially available rounds including Brown Bear soft point rounds (which I have hope for being decent) and the following non-commerical rounds:
I have recently acquired a half case of rounds with 220 grain lead nose bullets (yes, not a typo - 220 gr.) with a high burn rate powder load design specifically as a subsonic round. From my understanding this round should travel at just under 1000 FPS and thus not experience the crack from breaking the sound barrier -- the rest of the sound at the barrel end is going to be up to the suppressor. To the best of my knowledge the diameter of the bullet is still .310, but not completely certain of this without putting a caliper on it. As you might guess this ammunition is not priced the same as TulAmmo range plinking steel case, so I want to plan my testing accordingly.
Unfortunately with the bitter single digit cold temperatures here in Ohio, and the current state of the SBR (stripped down to the bone and still without stock) I have yet to experiment with the round in the 12" barrel. Hopes and expectations are high though.
If anyone else is experimenting with loading subsonic rounds and/or suppressing short VZ.58 barrels using 7.62x39 caliber, please contact me by PM as I would love to compare notes as I hopefully progress in the months ahead.
Back to off topic items, which are already in progress...
