Bought some WRA 270 WSM 150 BST ammo to try (not too impressed).
They claim 3100+ fps. Broke down a round for grins. (you don't want to see what happens when a teflon coated bullet is put into an unchamfered case by some machine)
We've been playing around with some different powders and bullets in the Benelli R-1 and the results have been underwhelming.
(why the rifle was not made in the "old" 270 is a mystery as it's a "long" action).
Moving along to the powder. The word is that W 780 is the factory WSM powder and the powder dumped from the factory load looks exactly like W 780. (really, exactly, even under a 10X loupe) But the case held 73.4 grains whereas the maximum 150 gr Hodgdon data load for W780 with a 150 is 66.6 grains.
We have tried that load (not very accurate) with several 150s.
What is interesting is the perceived recoil and jump with the factory load is quite a bit more than the W780 handload although the velocity difference is less than 100 fps.
So is Winchester keeping a secret or what ?
This R-1 wears a Nightforce so it's hard to believe it's a scope issue. Our other R-1 (300 Winmag with a 2.5-8 Leupold) is a solid 1.5" grouper (@100) with almost any 150-180 gr factory load as well as many handloads. This 270 WSM is lucky to put 5 in 6" @200.
Thought ? Thanks !