There are only a handful of 300BLK specific profiled bullets on the market right now. I can almost guarantee that your gun wont feed a lot of the common 300blk bullets if you load them out to 2.260 because the bullet will push to far to the left or right and miss the feed ramp completely and jam into the barrel extension and not the feed ramp. 250 and set that so that portion runs on the rib. In 300BLK it pushes the actual bullet hence why you have to figure out where your bullet is at. The rib of the magazine is the portion that pushes the case into line for proper feeding. For supers it seems everybody runs H110 or Lil-Gun, I dont see to many running anything else.

1680 and R7 seem to create a bit more gas to run the gas system than some of the other powders. There are 2 or 3 other powders as well that guys have had real good success with the subs. There is a guy running Lil-Gun for everything in 300blk with ok success, but I dont honestly think it works as well for the subs as something like 1680 or R7. I believe the lighter remington factory ammo uses H110(or the canister grade equivalent). With 300blk and the light stuff you can get 22+g of powder into the case which should give a very high % case fill hence why it is better for lighter stuff. Kinda scared me away from H110 after that and seeing my pressure signs. He has seen low case fill 44mag blow up a gun at a charge that should have just had low velocity. 98%+ case fill otherwise it can do weird stuff pressure wise. I talked to a buddy who has loaded magnum pistol(which is actually very similar to 300 BLK) stuff for years after I had pressure signs WAY early in testing H110 and he said H110 really needs high 90% i.e. H110 needs a high case fill percentage to not have wonky pressure curves. H110 for the light stuff up to about 125, maybe the 135 grain stuff. If all I had was H110, I wouldnt hesitate to use it, but like I said after doing a lot of research Lil-Gun seems to be a bit better for the mid weight loads. 16g just happened to give me great groups and no pressure signs so I stuck there.

I worked from 15.5-17g and had no pressure issues with Lil-Gun. I personally, and after reading a lot on 300blktalk, determined that Lil-Gun was potentially a better powder for the mid weight loads. I ran up to 17.2g(maybe 17.3) of H110 with the 150g FMJBT before having pressure signs.

150 gr subsonic 300 blackout