US 869 powder

[GLynn41]

I saw this on the Midsouth shooters supply site-- any inof as i do not know anything about it

[bearslayer]

very slow pdr brought out for 50bmg. Should be good in very large mag cases like ultra mags....I use wc872 (a little slower than 870) in my 7mmRUM...105gr x 140gr tsx gives me 3500fps. 872 is 3 powders faster than us869

[Ricochet]

872 is 3 powders faster than us869
Slower. The burning rate goes down as the numbers go up in the WC series. But with powders this close together, lot to lot variation's likely to be greater than the nominal difference between powders. I've had a factory data sheet showing among other things the nominal relative burning rates. (I think WC748 was the reference powder at 100%.) WC872 was 80%, WC870 (H870) was 81%, and WC860 was 82%. Different burning rate tables show these three powders in different orders, and their actual burning rates will likely differ in different applications. These things aren't absolute. The powder makers test them loaded at partial density in a closed "bomb," ignited with a hot electric wire, measuring the rate of pressure rise. Not the same as conditions packed in a cartridge under a bullet and fired with a primer.