kk, have you experienced any problems using the stock barrel? The reason I purchased a KKM barrel was because I had read that Glock cautioned against using hard cast (or maybe lead?) bullets in their polygonal rifled barrels.
John, they also caution against using handloaded ammo. Speaking as someone who's shot mostly cast bullets in my pistols for the past 20 years or so, the "no lead in Glock barrels" thing is a hugely overblown stinky brown pile.
The real issue with Glock bores and lead is with soft swaged lead bullets. You can run as much hard cast through it as you want, as long as the bullet fits the bore. Note - a while back Doubletap's hard cast 10mm loads were significantly undersized and caused a lot of leading issues. I don't know if they've corrected that; I don't buy them any more.
The earlier gen 2 and 3 10mm Glock barrels also had overly generous feed ramps making hot loads more prone to case bulges. They've addressed that pretty well in the newer guns though, yours should be OK. I'd suggest trying your hard cast ammo in your stock Glock barrels and just keep an eye out for any case bulges or significant leading (you'll get some lead wash, same as any barrel).
