I find the smaller bores giving greater shot to shot velocity variations. The old .58 Large barreled Hakwen I had in Smithers, as well as my current .69 both showed less than 10fps variation in a 10 round test - usually 5 to 8fps when using GOEX 2F powder - OR Curtis and Harvey 3F powder. Even back then, in 1977, I had my own chronograph and it showed great consistency in shot strings using TIGHT ball and patch loads. Short Starter - you betcha.
I well remember Fadala's articles, claiming the cloth patch was an "ANTI-Gasget" that worked against sealing. Wit the .010" undersized balls and thin panty material he was using, it's no wonder his velocities increased when he used wads behind his 'combination' to seal it. That was his proof the patch didn't seal. When he tried his wasp nest with a Primitive Rifleman's decent ball and patch combo, there was no increase in velocity. He chocked that up to an annomoly because HIS tests proved otherwise. I protested these errors to John Baird, John said to me, "Daryl, let him be, we know his combinations are too thin - he's on a long learning streak and needs to feed his family".
Recently, Taylor's own chronograph testing showed something like 4fps difference in his BP ctg. gun using Swiss 1 1/2. Since I have some of that powder, I am wanting to try it in the .69. It's GOEX consistency is wonderful and probably explains to some part, in that rifle's accuracy - but better accuracy yet is, well, better.
"Consistency, though art a jewel!"