Cleanest burning powder for SubSonic?

[roxy]

Do you have a pet load that is a clean burner for shooting suppressed subsonic 300 Blk.

[dcsmith1]

AR or Bolt action?

[roxy]

AR or Bolt action?

AR Platform w/16" Barrel

[300Blk]

Probably Bullseye, but it won't cycle.

[300Blk]

Does it also have to work well? There are only three powders that work well - A1680, H4198, and RE7. They are all about equal in cleanliness.

[BachelorJack]

We've got a pretty sweet N320 load with 180gr. Doesn't cycle. Use it primarly with gas systems disabled or bolt guns.

[robpiat]

IMR 4227 works great for me. Not sure why it isn't mainstream.

[82nd airborne]

Does it also have to work well? There are only three powders that work well - A1680, H4198, and RE7. They are all about equal in cleanliness.

Surely you jest! There are alot of powders that work well for subsonic, Ive listed them before but I'm too lazy to do so again. I must say, 1680 is the dirtiest of all of them that I have tried, and we are talking over a dozen powders.

[82nd airborne]

IMR 4227 works great for me. Not sure why it isn't mainstream.

+1
4227 with 210 SMK's, 208 Amax, or 220's works great!

[300Blk]

I have shot a lot of powders on high speed video and ruled out a bunch.