I agree. I use a ball .010" under bore size and a patch of .024". It's tight but still loads with the underbarrel wood rod. Normally no wiping is needed until I get home.
That usually works just fine, Hanshi - however in a Rice round bottomed grooved barrel with .016" deep rifling, a .020" patch with a ball that is .010" "under", can cause gas leakage seen as brown scorch marks on the recovered patch on lighter loads. The scorch marks follow the barrel's grooves as seen on a recovered patch. With a heavy-type hunting load, the increased pressure can then gas cut the .020" patch and cause flyers and inconsistent ballistics. The extra .004" can and may help in this regard. In a standard .010" or .012"depth of rifling that is a good combo.
Case in point how different barrels can be. My 14 bore rifle (.012" rifling but not a smooth barrel) does not like a heavy hunting charge with a .0235" patch (railroad-ticking) with a .684" ball (only .006" under bore size) so for the heavy hunting loads, I must use 12 ounce denim which I measure at .025" with closed firmly mic and .030" between crushed caliper tines (average of 3 dial calipers I have). What I found MOST interesting is that those heavy hunting loads do not hurt that 12 ounce denim patch when using the grossly undersized ball, ie: a 15 bore ball at .677" in WW or .675" in pure lead, yet the ball is .013" to .015" smaller than the bore size. The patch maintains it's integrity with either pure lead or WW ally balls. These undersized balls are easier loading than the larger one. I have not, however tested them at 200yards which should show what ball size and load is superior.
Due to the plethora of different measuring devices and methods thereof, one must do his own measuring. I find naming the denim by it's weight in ounces, is about the best. All of my rifles except the .69 (14bore) like 10 ounce which I measure at .022". As noted the 14 bore likes 12 ounce. I use 8 ounce in the .45 handgun due to it's easy loading and fair accuracy with the .445" ball. I measure 8 ounce at .0185".
None of my guns EVER needs wiping while I am shooting THAT day. If left sitting for a while before loading, and if I was in a paper group match, I'd probably wipe it or load with a very wet patch and fire a fouling/cleaning shot. There is never more than one shot's fouling in the bore- it does NOT build up as the day goes on - impossible as the last shot's fouling gets wiped down, every time it's loaded.
Indeed, with the big gun, after shooting 10 non-lubed paper ctgs. the bore is fouled - then I load a VERY wet patched ball using normal 10 ounce .0225" or the railroad ticking (.0235") patches with 3 drams (82gr. 2f ) and fire that. Now the bore is freshly cleaned & only has one shot's fouling, thus I can shoot another 10 paper ctgs. without loss in accuracy over round balls with normal paper patches. In that rifle, I have never tried anything but the 6 dram 2F hunting load with paper - I do not know if light, 3 dram loads with paper are as accurate as patched round balls. ALL of my best long range shooting, from 100 to 300 meters has been done with the heavy loads. No wiping needed as long as the patch is thick enough to do the work of cleaning and sealing the pressures behind. To do that, it needs to be tight.
I should emphatically note here, that the ball and patch must also impress the ball's exterior in the very bottom of the grooves. Muzzle started and pulled, the ball must show cloth weave over it's entire surface, heavier where the lands are, lighter by the grooves, but still show the cloth's weave impressed into the ball from the bottom of the grooves. THAT is a snug load and one that will not let you down.
