James, In my .62 & in my sons .62 cals with Colerains we are shooting a .600 RB with .018 pillow ticking & Lehigh Lube, 85 grains of FF Goex. We have tried the .610 & you need a hammer to start them & I am not using a hammer to start balls. I want to rap them sharply with the ball of my fist with the lil stub of a starter, then the short starter with my palm & then the RR.
As for balls, you can order them from Eddie May in GA as bout cheap as anyone. 1-706-695-5290
I suggest ya pour them yourself as you can get pure lead from a scrap yard for about .25 to .30 per pound. Great hunting caliber gun but too expensive to shoot all the time, as you will find out if ya shoot it much.
When ya get it done I will send ya a few of the .610 & .600 if ya want so you can try them & see what it will require.
As for the Warren Bullets, I don't care for them. I have probably a doxen boxes of them here now & they are not uniform & I have trouble starting them in all of my guns. Example is on a .535 ball, mic it one place & it is .535, turn it & it is .525, another place & it is .530. They are all over the place. Same way with the 5-6 boxes of 40 cal balls I have. I bought them on sale & it would have been a good deal if they were consistantly sized.
Rush Creek seems to have some pretty consistant balls. I checked them out at Friendship last time & they were OK & very reasonable if you buy in 500 or 1000 lots as I do. Plus no shipping if you are there & with the cost of shipping today, that is a big deal.