That guy is a heck of a shooter--sounds like he did something very similar to his stock though probably a bit more "deluxe"--I just use marinetex epoxy and envirotex.
Funny you mention it--I was out shooting my 6mm creed AR build yesterday for the first time in a while--I haven't found a load yet that works quite that well but yes the H4350 is one of my principal go-to powders. I found a formula using 4000MR and decided to try that out on 108 eld's. Unfortunately had to stop shooting right after starting in, so testing remains to be completed. My odin barrel has a 1:8 twist so theoretically it might have issues with the bigger bullets--I'll see.As far as the 6 creed cartridge is concerned, I've got it in a custom 700/7.5 twist krieger and it shoots .2s and .3s at 100. H4350 and very good ballistics. One of the best shooting rifles I've ever owned.
I haven't really noticed the extra weight--especially when compared to any solid wood stock rifles I have. It's just a cheap option for those on a budget that I know works.One thing to keep in mind if you are weight conscious is that adding a bunch of epoxy to a stock will make it noticeably heavier.