your 5050 clip on stick on alloy is NOT to hard. If anything its to soft. Switch to just plain clip on ww and ditch the tumble lube and get a lubesizer and use a quality lube or do some research on PC coating if you don't want to buy a lubesizer. If you just want to get rid of the light leading about every 50 rounds or so shoot a couple jacketed bullets through the gun. Unless you have bad build up of lead that will take care of it. Ive got 3 glock 9s and two smith m&p 9s and a ruger and all shoot bullets sized to .357 with no leading. Been loading cast 9s for many years and have shot 100s of thousands of them through about every brand of 9mm handgun and even in rifles. Only keyholeing ive ever seen was a few guns did it with heavy 147s unless pushed hard enough to get enough spin to stabilize because of twist rates. Ive shot 100-120s at every level from pop gun loads to screamers and never seen any keyholing. My guess is your soft bullet is stripping through the rifling and that's why it gets worse with faster powders that give the bullet that little extra umped into the chamber. that problem is accentuated by the fact that many handguns have shallow rifling. Glocks in particular. Harder is about allways better in a gun that is in spec. That old soft bullet to bump up theory came from back when colts and even smiths and rugers had guns that chambers and bores had specs all over the place and even misalignments between them. think of it this way. A jacketed bullet is harder then ANY lead bullet and does your gun shoot them well? Bottom line is when you intentionally cast a bullet to bump up what your doing is causing it to deform to fit your gun and its not going to deform the same way every time and is for sure changing to bullets shape to something other then the designer of that mold intended. If a gun needs a bullet to bump up to shoot half way decent id send it down the road and get a different gun.