Powder grade

[Old Ford2]

Shooting a .69 and .75 cal. guns would 1F burn well, or would it be too slow.
Perhaps 2F ?
The .69 is 32" long, and the .75 cal. is 40" long.
My .62 caplock prefers 2F.
Recommendations will be appreciated.
Fred

[Daryl]

Fred, I think 1F would burn just fine in either barrel, however, if smooth, patterns will tell which is preferred, 1F, 2F or 3F. 

With a rifle, higher muzzle pressure from a slower, more progressive burning powder, will disrupt patterns more than a lower

muzzle pressure developed by a faster burning powder.  Of course this depends much on the actual charges used.

I would be inclined to 'test' this prior to making up my mind on what was better. I have heard of guys getting better patterns

in smoothbores when using 3F, than 2F.  I use 2F, however my little 20 bore has a slightly imp cyl. choke & makes modified patterns for me.

[Old Ford2]

I use both 2F & 1F in the shotgun, but I think 1F may shoot well enough in the .69 and .75 rifles.
IF supposedly slower burning my help in recoil being more of a push, whereas 3F & 2f  has more of a snap recoil.
These two calibres will be eating 120+ grains of powder per shot, and hope the recoil will be more neighbourly.
I shoot large bore cartridge and am accustomed to substantial recoil often enough.
I really want to enjoy these dinosaur guns without dislocating my shoulder, but in reality these bores are no greater than a Brown Bess.
Thank you for the information.
Fred