Re: .375 Cheytac or .375 Snipetac
I have never had any hangfire issues with my 375 Allen Magnum which is just a lightly more extreme version of the Snipertac. In reality, performance wise, very similiar, just a bit different case design.
I have used up to 146.0 gr Retumbo and as low as 135.0 gr retumbo under the 350 gr SMK and never had any hangfiring. From velocities from 3100 up to +3300 fps.
Perhaps your hangfires are more from the increased body taper and shallower shoulder angle and maybe a bit to much bump on the shoulder of the case?
It has never been a problem to get low teens for extreme spreads with any of my 375 AMs but as Joel mentioned, they are very consistant.
I considered the fireforming issue when I released my 375 AM as well as my 338 AM and that is why I had Jamison make me my own headstamped brass and I offer fully formed cases for customers to eliminate that concern and barrel wear.
If you look at the factory load specs for the 375 Chey Tac, there is much more to be had with the Improved versions but that is mainly because Chey tac loads their ammo rather mildly by most standards and the ST and my AM are loaded to top working loads.
With my accuracy load, 144.0 gr Retumbo under the 350 gr SMK, I am running around a 95% load density. Still air in the case but plenty full and no chance of powder fracturing.
I am surpised you had hangfire issues with H-50BMG but not with US869 or AA8700 which are much more difficult to ignite then 50 BMG.
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
Farther, Faster and Flatter then ever before.
Web Page: www.apsrifles.com