Yeah, I certainly can’t complain about Retumbo’s accuracy with this bullet. But after being used to H870 the velocity was just depressing, lagging behind by a good 100 fps. I was getting 2850 with the 26” factory barrel. At 26.7” I’d expect this one to top out at around 2875 or so with Retumbo at the same sensible max pressure.
So that shouldn’t be tough to beat. That’s all I was really hoping for with US869—a powder that will keep the accuracy, be somewhat temp stable and beat that velocity (especially with an eye on even heavier bullets in the future). Basically a replacement for H870 with the added bonus of being temp stable (claimed, at least). H50BMG would beat it by 50 fps but accuracy was lousy.
I’d say US869 has already passed the accuracy test for me, and velocity-wise Retumbo sets the bar pretty low—it’s just too fast to be optimum with bullets this heavy. If my educated guestimates are correct, it should beat it by a significant amount.
Somewhere between 1500 yds and 1600 yds. Looking @ exbals #s it should not be going into the transonic phase yet but, it would go from kicking dirt on pds to hitting in a 10' circle around them!! Might also be that I'm shooting them out of 10" twist. Don't know why, I just know that is what it does.