Maximum feet/second for gas checked cast bullets ?

[Gaz-52]

       I am in the process of working up a load for a 150gn. gas checked cast bullet in a 7.62x39 single shot rifle. Can anyone tell me at what point I could expect leading to become an issue ? Its a new rifle and I am breaking in the barrel with cheap jacketed ammo ,but it will be used to shoot cast exclusively once break-in is finished . Any input would be appreciated  .
        Gaz.     

[Graybeard]

Using that caliber and bullet weight if you experience leading it will not be because of velocity.

[Nobade]

Yep, GB is right on. If the bullet fits, is hard enough, and uses good lube you can run full throttle and then some with a 7.62X39 in a bolt gun with no problem. My little CZ carbine is a cast bullet shootin' trick with way better performance with cast than it can manage with jacketed. (They also work quite well with soft bullets paper patched for hunting.)

[Bob J]

I have to agree with the previous posters......  Properly sized for the barrel is the most important with a good lube second....  Also you want to load from the slower end of the powders....  Get it right and you can push them pretty much as fast as you want without significant problems....

One other thing worth mentioning.....  If you are changing over from jacket to lead make sure the barrel is well cleaned of any copper fouling.....  Lead likes to bond to copper (think solder)....

[anachronism]

We've hit 2800 fps without serious issues. This was with a 375 H&H and 260 gr gas check bullets. We run 30/30s flat out, using jacketed load data, 30/30s are especially accommodating in this respect. You should be able to achieve similar results with  your rifle, but as stated before, the bullets have to fit properly or all bets are off.

[Gaz-52]

          Thanks for the feedback fellas. I have started working up some loads using ADI 2207 which is similar in load density and burn rate to 4198. I am up to 22gns and groups are still improving,I wouldn't expect this Baikal 18mh to get close to a CZ's accuracy but you can only try.
  I am tumble lubing with Lee liquid alox , and there is no leading so far. Seems to leave a lot of soot in the barrel. Would a light crimp help ?
   I have had the odd FTF ,light firing pin strike issue which seems common to these rifles. Cleaning out the factory grease and crud remedied that problem but I think a trigger job will be next.               
         Cheers Gaz.