Antimony makes your alloy harder, tin makes it cast better. Regardless of what else is in your pot, a little tin is usually a good idea. I used pure lead to pure tin at a 25:1 ratio for my Schuetzen bullets with excellent results. For pistols and especially revolvers, I like old COWWs with just a % or two of tin to make them cast better. Lately range scrap is getting more attractive, and I can just cast it as is or add a touch of tin to make the bullets fill out better.
Your smearing and skidding experience is more likely a function of sizing rather than anything else in pistols and revolvers. You should begin by sizing your bullets a bit over groove diameter (say .001") and lube properly and your leading problems will probably go away if your barrel is any good at all. Harder (or softer) won't make all that much difference at handgun velocities if size is right.
Froggie
PS Swaged HBWCs are just about pure lead, and I've shot many thousands of those through my 38 revolvers without any significant leading. Again, the size of the bullet is the thing.