RE: ffG vs. fffG?
slee,
you will probably do well by trying the 3fg in your Renegade. It is cut VERY fine - it literally is powder, not granules..............in looks it appears similar to 4fg BP. Which means you need to be careful when you measure 777. Do Not compress it any in your powder measure - pour the powder freely into the measure, cut it off at the top & pour it in.........don' t tap or thump the measure to try to get it to settle. Doing so could easily allow you to pour in up to 5gr more powder than you want.
I have found that you don' t need to reduce your load any between 2fg & 3fg 777. Both are cut small & there is only that 50fps difference between them. The only difference I saw (or felt) between identical charges of the two cuts is that group sizes shrunk with big bullets when going to 3fg. And seeing now what the max charge is for your gun - I' d cut the 777 off at 100gr.............which is all your shoulder would want to fire anyway.
Before your buddy sells that Black Diamond, have him scrubb it down REAL good with a bore brush & BP solvent - the CVA Sabot solvent would be good. Then try some 300gr sabots like the Hornady XTP Mags over 80gr of 777 - I think he' ll see a big improvement. If not, scrubb down the bore again and shoot 2 or 3 dozen patched round balls out of it with 70gr of 777. Give it another scrub & try the XTPs & 777 again. If it won' t shoot then, it might be time to consider another shootin' iron (BTW...make sure all is well with the sites, scope, mounts, etc as well).
Good Shootin'