Smp248

Came into a rather large amount of it from a friend's estate. He used to work for a commercial reloader. I would guess that is where it came from. His 650 was set up to load 5.5 grains with 180 in 40S&W. Chromo data said that load made 900 FPS.

Any idea on other data or a comparison powder?

According to QuickLoad, Vihtavuori 3N37, Vihtavuori N350, Accurate #5, Hodgdon HS-6, Alliant Power Pistol, Ramshot True Blue, Hodgdon Longshot, and Winchester 540 fall into the 5.2 grain to 5.6 grain range. All fill the case from 60% to 80% and give an estimated velocity of 900 fps from a 6" barrel. You might check powder type, ball, sphere, extruded, whatever.

I DON’T SAY THESE POWDERS CAN NECESSARILY BE USED WITHOUT CHECKING PUBLISHED RELOADING DATA…

But this might give you an idea as to the powders that might be comparable…

Good-luck…BCB

A couple things, "SMP" would seem to suggest Saint Marks for an origin? Is WW540/HS-6 a saint marks powder? AA#5 Saint Marks? It is a ball powder.

Another place in his notes I found 6.7 grains as max with that same 180rn in a 40S&W, at 1.15"

Maybe Winchester Autocomp?

Found info in his notes that this may be Winchester Action Pistol. Cardboard drums were marked "OBP 248", but when he transferred it to plastic jugs they were marked "SMP248".

You may find this useful, from the horse's mouth-

http://www.imrpowder.com/PDF/MSDS%20...ers_090111.pdf

Its just a matter of figuring out which Hodgdon/IMR/Win powder it is.

This list from St. Mark's/GD lists a few powder names and applications, but nothing for OBP2xx-

http://www.gd-ots.com/download/BALL%...ropellants.pdf

Started my own Chrono work, in a 40 S&W, 5" barreled 1911, 165 jacketed, WSP, 5.5 grs did 1010fps with an extreme spread of 18fps over 10 shots. Complete burn, clean brass, primers very rounded. Very easy to shoot load.