I have a 6 MACH IV (.264 Win. Mag improved and necked down to 6mm). I am trying to get 3800 fps out of a 105 gr. bullet. I have tried Rutumbo, but pressures get too high at around 3400 fps. Has anyone out there have any data or experience with this the round?

Mach IV with very hight velocity heavy bullet works with real 50 BMG powder as Vita 20n41 , H50BMG ... pressure are OK but bad thing is a lot of carbon fouling due to burning very slow powder in small bore

What pitch you have ?

good shooting

DAN TEC

jrec3.....I built my .240 Incinerator at the same time that Seyfried was doing the Mach IV. Anyways, I have an article on my website to include loading data. I was able to get 3,800+ fps with a 100 grain Nosler using 84 grains of WC872....AA8700 also could hit 3,800 with a 95 grain Ballistic Tip. Surplus/machine gun powder is definitely the way to go with this round (I also don't know what barrel length you're using, but mine was cut to 28.5"). Best of luck.

Lee Martin
www.singleactions.com