The Barrett is not really that pickey about what goes through it.

Vihtavouri 20N29 powder with A Max 750 bullets is a pretty consistent combination. WIth lighter bulets like 647 grains the N49 or Hodgen 50 powder works better in the Barrett.

I use CH dies and a monster CH press.

The real fun stuff is surplus Armor piercing incendiary. Just have to a bit careful when running those through the swaging process. The die for that is also from CH.

I have not yet tried the Lapua 50 caliber bullets (just a bit pricey). The new 50 bullets from Lost River look real interesting, but at $45 for 20 bullets, I'll wait until someone else does the load development work. That is closing in on the cost of fully loaded military surplus, and the Barret likes mil surplus just fine, which is a good thing for a 10 round semi automatic.

I did buy some 800 grain bullets from Gerard Schultz at GS custom, but have not yet had the oppportunity to work up any loads for them.