For cutting the sprues, I use a pair of side cutters with the back ground down to almost flat meeting of the jaws. Snipping the spures off leaves a tiny raised spot that can be left, or as tom noted, filed off. The larger the balls, the easier they are to handle as to sprue triming. Too,you can use the plyer's type wire strippers, the ones with the little holes. By cutting close the sprue to the top of the ball, and twisting the ball, the sprue usually comes off quite clean and no further work is necesasry. Lost my wire strippers somewhere in the mess, so I'm using the gorund side cutters right now. Jeff told me he uses ground side cutters.

I'm using RCBS, Lyman and Saeco handles on my Tanner moulds- and I need more handles for the new ones.

For that smooth 6 bore - measure the bore size itself, then subtract .025" and that's the ball I'd use, with a .020" patch. So - for a .919" bore (true 6) I'd be ordering a.894" down to perhaps .890" mould.

I have not tried wonderlube for many years, although I've been told it will build up in the bore and grooves of a rifle and hurt accuracy & that is its difficult to remove when cleaning. For cold weather hunting, I use mink oil from Trackofthewolf. It allows unlimited shooting without having to wipe, when using normal hunting loads.

WW balls smash bone better than pure lead does, and I use them in my ctgs. for a fast second shot - if needed. My first shot is directed at the lungs, second is on the shoulder. The ball actually smashes the bone quite well, continuing on in a straight line, compared to a slug which usually glances on leg bones. I've not found a reason to harden a WW ball, as they are plenty hard by themselves. Be careful with clamp-on WW, that they don't have a 'Z' stamped on them. Those are zinc, which will destroy your melt's good casting properties and foul the pot. Glue or stick-on WW are almost pure lead and will soften a mix.

1,300fps is just fine for anything this side of the pond - from a big bore. In a well made 12 bore, 140gr. 2f would probably be my charge for moose, elk and bear. That means exits on most game, which I also like. They would be running up to perhaps 1,350fps, I think - depends on the powder and fit of ball and patch. For me, only snug loads work and those need a short starter. Once into the bore, and with a good lube, they go down easily. If fouling builds up, the patch and ball combo isn't good enough, or the lube is failing. Even spit will allow any charge your shoulder can handle, but of course, it isn't a hunting 'lube'.
The lower the velocity, the better judge of range you must be due to the arched trajectory. It is a wonderful thing to have a point blank range of 100 to 120 yards with a big bore, but you'll need 1,500fps to get it. Back in the late 70's my bro shot a moose at 95 yards with his Brown Bess, a .715" ball and .025" denim patch. The ball stopped underneath the hide on the off side after punching ribs on both sides. I still have that ball, quite flattened. His load, a piddling little charge of 100gr. 2F- for about 1,100fps. The hole through the lungs was about 2 1/2" in diameter - due to the shock wave ahead of the ball, no doubt.