ORIGINAL: BS
A 140 grain load of FF should put you really close to the 1350 mark.
What is your bore size, a true 12 ga. is .729, that .735 must take a stiff wrap to start...........or is your bore bigger?
I shoot .725 to .705s out of my 73 cal, but it only has a 26" long tube. The 725s weigh in the 550 grain area.
Thanks, BS. I too was thinking of starting off with 140 grains of Swiss FFg.
When I slugged it, the slug showed the land diameter to be right at .730" with a groove of .7385". The .735 ball will sit on the muzzle without a patch, and it does require a pretty good whack to start it even with only a .010" patch. However, the balldoes not have to be hit hard enough to deform it or leave a mark when using a 0.50" diameter hardwood short starter.
Where didyou find .725" balls? Did you have someone make you a .725" mould? I have some .715" balls and some .735" balls, which I purchased locally. But I believe BOTHthese diameters tobe a compromise, as somewhere between.720" to .730"would seem to be closer to the ideal diameter for this bore. (The barrel maker, Riley Smith of Long Hammock Barrels, said the barrel would be a .73-caliber, and it is!) I can certainly shoot it with the .735" balls, but these might be a little slow loading for hunting. I have not tried the .715" s yet, but with the right patching these might prove satisfactory.