Thats the problem,the GPR hammer is setup for the shorter Lyman nips. The HotShots ,RedHots and others are longer so the hammer contact with the nipple is at the extreme upper edge of the hammer...if you'r lucky. Plus when you go to half cock the hammer may still be making contact with the nipple. I think thats why Lyman recommends against using the HotShots. Theres a post in the "Campfires" Muzzleloader section regarding tweaking the hammer posted by RollinB,hope he doesn't have copyright protection and sic a pack of lawyers on me! :lol:
"To "tweek" the hammer it must be removed from the lock "AFTER" make'n note of "how much" and in "which direction" it must be bent.
Clamp the hammer in a vice along with a piece of wood represent'n the nipple for a "reference point". a vice-grip or cresent-wrench can then be used to carefully bend the hammer so thet the "hammer-nose" lines-up with the reference-point. Avoid "bending" too much, by try'n it on the lock itself to see how much progress yore make'n. It's possible to git it "right" the first try,.... jest go slow, and think everthin out so thet you don't have to "un-bend" the hammer if possible, cause "un-bend'n" is usually what will create a fracture in the metal.'
I don't know if this will help the halfcock problem any. I'd use a peice of cloth to protect the hammer from getting dinged up by the vise and/or vice grips.
Jeff