I was getting a seating depth worked out for my .308 casts today. When I closed the bolt with the 170 and 180 grain lead slugs with gas checks, I determined that 2.64 was the length of the cartridges as they came out of the chamber.
So, setting that back a few thousandths, I get (duh) 2.60". That's pretty short, and I had a hard time (read "could not") find load data to support this COAL.
Currently, IMR 4895 is one of the two powders I have listed as acceptable in this cartridge. It seems that it is one of the better choices for reduced loads.
The closest load data I could find was on Lyman 49th, on page 222 I think, where 4895 was spec'd out at a starting load of 33.x grains and 2.675".
I see where 4895 can have the starting loads cut by 60% for reduced recoil. Is that where you would start? Or would it be more like 25 ish?
I know enough not to presume things like this are a simple mathmatical ratio, and that things like chamber pressure increase in a logarithmic rather than a linear way.
I guess I'm trying to tap into the collective wisdom here. I would assume, given a slightly smaller coal than specified, that cutting the beginning powder charge by 40%....but I'd rather ask for guidance and not be sorry than not ask and have something bad come my way. This year's had enough bad stuff for two lifetimes already.
Thanks fellers. (and ladies too)
Regards,
Bull