B.P. residue

[jednorris]

I have been shooting a .40 Cal. Browning using 59.0 Gr. of Swiss 1-1/2 with a 400-gr. bullet. A couple of months ago I purchased two cases (50#) of 1-1/2 Swiss, both of the same lot #. I found with the new powder the "loft" in the cases to be considerably higher, but I shot the same load. At first the accuracy remained about the same, but fouling was terrible. I am getting twice the amount of residue on my patch when I swab after the shot and I think I am losing accuracy as the string goes longer. I am going to reduce my charge to 58.0 gr. to see if I just have too much unburned powder. Could it be my powder and if it is, any suggestions?

[charlie b]

Post this question in here

https://castboolits.gunloads.com/forumdisplay.php?30-Black-Powder-Cartridge

[Sam Sackett]

I’m not an expert on black powder, but I believe the 1 1/2 refers to the grain size. Handgun rounds usually use a finer grain size (FFF). I think the 1 1/2 may be too large and you aren’t getting a complete burn. Hence the heavy fouling residue.

Hopefully someone that knows more about BP will jump in and give more info.

Just my guess…..
Sam Sackett

[BLAHUT]

the reason I quiet using black and went to blackhorn209 subitute.

[Super Sneaky Steve]

It could be the humidity or a number of other factors. 1.5 seems pretty big for a 40cal. I would put that stuff in a ceramic coffee grinder and make some 3F. What kind of boolit and what kind of lube are you using?

[dondiego]

Swiss powder grading system is not the same as the US system. 1.5 Swiss is more like 2F in size. Maybe smaller.

[tmanbuckhunter]

BP isn't like smokeless, where the lot to lot differences are minute and hardly noticeable. There can be a dramatic difference from lot to lot, even with something like Swiss. Re-work your load and see if fouling persists.

[jednorris]

When I reduced the load from 59.0 gr. to 58.0 gr. the fouling problem and the accuracy both improved. I think I am back to where I need to be, I am just a little surprised of what a difference it made.