Which powder?

[Kosh65]

[GSPDad]

Buy both and see what work is the way to answer your question. That rifle may hate both, or like both, or only like one of the two, but you won't know until you try them both. As far as velocity is concerned, there isn't much difference between those two and 8208 generally has a touch lower overall cup/psi than benchmark until you try to really push at the upper end of the max ranges with the powder. 8208 can spike pressure rather quick and I find it to be inconsistent from lot to lot and it can be finicky at times.

[Chuck N]

[xlcc]

My go to powder for my Howa HB with 100 to 123 gr. bullets is 8208XBR.Very good accuracy and velocity.Never had any issues with powder spiking like others have stated and I'm running compressed charges.Seems to work well @-30 to +30 C.Burns clean as well.I'v killed quite a few wolves,coyotes,big cats and large deer with my Grendel and XBR.

[Klem]

Brian,

I would use neither, especially with your long barrel. I only use those two for lighter projies, preferring 8208 and only BM2 (even faster) if there's nothing else.

Both are single-based powders made by the same company that makes H4895. H4895 is slower and more suited to accelerating heavier bullets down a long barrel. They all will work but the most efficient (highest velocity) will be H4895.

BM2: A heavy 130gn will max pressure out at 25gn but with only 85% of the case full. Approx 2,400fps.
8208: A heavy 130gn will max pressure out at 26gn and will be closer to filling case capacity (98%). Approx 2,440fps.
H4895: A heavy 130gn will pressure max out at 26.4gn and will be close to case full (99%). Approx 2,480fps.

All three are about 100% powder burnt in a 24" barrel so no worries there.

[Zeneffect]

if you have either available to you, get both of them as you probably wont be able to get either once others find that stock.

my gas gun loves some 120gr sierras and xbr. absolutely LOVES them. 120gr where i would stop with xbr, anything heavier and things get weird with the load.

30.6gr xbr + 120gr smk = 2500fps and 1/2 moa with shooter error on my gun

[Kosh65]

Thanks for all the replies. I have limited experience with the Grendel. But the more I shoot it......the more I like it.
And Because I have no experience with either of these powders, or H4895 for that matter, is the reason I asked.

Please keep the great wealth of knowledge coming.

[Harpoon1]