OK, you hear about some rounds leading the barrel (right term?).  My question is this a real concern and how many rounds does it take to make a difference?  Also, does a good cleaning make this a moot point?  Will FMJ rounds solve the problem?

Yet another silly question from me.

I shoot lead against those metal spinning targets with 9mm and .40. It seems that the more lead that is deposited in the barrel the worse I shoot(That's my excuse at least).

I have heard that FMJ rounds will "clean" some of that lead out but it doesn't work for me. The lead is deposited on the barrel in sort of a molten state so you need more than a liitle copper scraping by to get rid of it.

The makeup of the bullets will determine how much leading there is and how soon. I would say to experiment and see what works best for you.

If you are reloading the lead keep the loads a little less hot than normal and that will help cure some of it.

Glocks don't like lead and lead up like crazy. In a worst case scenario a ring of lead can build up just in front of the chamber and cause a high pressure situation that could end in a KB. Lead is best left to bullseye and cowboy action shooters. FMJ is more expensive but cuts down on the cleaning issues.

Cheap lead (soft) at quick velocities will do it every time. A stainless steel bore brush does a good job of lead removal (off course I know you should never use a stainless steel bore brush.)

Most hard cast lead bullets need to be shot under 1000 fps.

If  you reload you can work  'down' some loads to about  600fps that will actually clean the barrel.

With Glocks  , if you stay under 1000fps and shoot a couple jacketed bullets every 3-500 rounds you won't have a problem.

After shooting a few hundred lead rounds with a replacement Glock barrel, I always shoot a box or two (50 or 100) rounds of FMJ rounds later on to get rid of the lead buildup.

It works for me!