Anyone beside me load surplus powder

[Beltfed]

I have quite a bit of surplus left over from my machine gun days at Knob Creek. Gots lots of primers and tubs of military brass, both .30-06, 7.62mm, 5.56. No knowing the proper powder charge I purchased several of the Schuster vented gas plugs in both .30-06 and 7.62mm. My plan is to shoot GI M-2 ball and GI 7.62mm (I have lots of both) till I get the bolt to function correctly. Then using the surplus powder, start working up in .5 grain increases till the bolt functions correctly again. As far as the 5.56 goes, I’ll use AA2520 as I have plenty of that also. I believe this surplus powder is too slow for the ‘mouse gun’.
As components are very hard to find these days, I would like to preserve my commercial powders. Anyone else going down this path?

[Smokey]

Right now you'll have to plan on working with what you already have. Reloading components are cleaned out as well. Stuff does show up but is almost immediately bought out.