pure lead 238gr in 7.62x39 asking too much?

[Oyster Stew]

Ok here is a question to you bullet casters.

This 238gr bullet is made for a 308 (.309) I want to stuff it in a 7.62x39 to make a subsonic load. Now I know one prob could be potential gases could melt around the bullet now lets say said bullet was coated with http://missouribullet.com/results.php?category=23 its a coating that protects the lead like a jacket.

I would just like to know your thoughts / suggestions.


bullet reference:http://leeprecision.com/mold-dc-tl309-230-5r.html

[TMD]

Its a great bullet for subsonic loads in a .300blackout. In your x39 doubtful. If like most x39's you probably have a .311 bore so if shooting lead you need a .311-312 bullet. At .309 even powder coated enough gasses will get by to heavily lead the barrel in no time.

[Oyster Stew]

thanks for the reply its sad news but I cant say I didnt guess that.

Im trying to find a nice sub load for it but my options are limited with .311

[skizzums]

this should solve your problem, coat them yourself.
http://westernbullet.com/311299br200gr.html

http://www.midwayusa.com/product/562...dius-gas-check
20 bucks is a small price for free bullets.

[Jimro]

This 238gr bullet is made for a 308 (.309) I want to stuff it in a 7.62x39 to make a subsonic load. Now I know one prob could be potential gases could melt around the bullet now lets say said bullet was coated with http://missouribullet.com/results.php?category=23 its a coating that protects the lead like a jacket.

I would just like to know your thoughts / suggestions.

According to Lee, bullet length is 1.363"

According to JBM's stability calculator, even a 1:10 twist can stabilize a bullet that length and mass at 1100 fps. The CZ 527 has a twist of 1:9, milsurp AK/SKS 1:9.45, and Ruger 1:10.

That being said, some folks with .308 bores in AR-15s are having issues stabilizing these bullets.

You are well into the "no published data" area for what you are looking at, but I would start with 300 Blackout data (smaller case size) and work up from there for 7.62x39. You'll need a little more powder than the blackout to reach the same velocities, but you should be able to hear when you break the sound barrier and know to back off from there. I'm not worried about pressure here because you are looking to stay subsonic, and the pistol powders used in the 300 Blackout are not used in quantities that produce excess pressure at subsonic velocities even in the smaller case.

I very much doubt that any subsonic round will be able to cycle a stock AK or SKS, but it might be the cats meow for a CZ 527 or H&R Handi Rifle.

Good luck.
Jimro

[tangolima]

It will work, basically.

Twist rate of 10 should be able to stabilize the bullet, which means no tumbling. But for good results at subsonic speeds, a tighter twist, say 7, will probably be needed.

It is a rather long bullet for 7.62x39. You may need to seat it deep to fit into magazine of some rifles.

-TL

[Jimro]

With cast bullets the slowest possible twist that stabilizes the bullet is usually the best option from an accuracy standpoint. Usually. There are a lot of caveats with cast bullets from rifles.

Jimro

[chris in va]

If I want 'subsonic' x39's, I just cast my usual 155 grainers over a pistol powder charge for around 1000fps. It doesn't expand the cases as it should with rifle charges but makes for zero recoil fun.

[T. O'Heir]

238gr in 7.62x39 is too big. Friggin' thing's be almost as long as the case. .308" or .309" is the wrong diameter for 7.62 x 39 too.
"...POWDERED 2-EXTREME HEAT-CURED SUPERCOAT..." Is powder coated paint.

[Jimro]

T. O'Heir, depending on the rifle the .309 bullet may do fine, Ruger used a 308 bore on their Mini-30.

Jimro