I have a Glock 20 10mm that I purchased over a year ago from Bud White. After getting it, I sent it to Robar Industries to get one of their grip reduction and high ride grip reductions.

I lucked out and found someone on Glock Talk selling a new Bar Sto match 10mm barrel which was expertly fitted by Robar gunsmiths. I also installed a pair of Tru Glo TFO sights and a Glock armorer fitted a NY trigger spring. All of these mods makes my G20 a special 10mm indeed.

Now comes the "heresy" part: I want to purchase a drop-in .40 S&W barrel for my gun. The reason is because my agency issues me .40 S&W training and (a limited amount of extra) duty ammo. As such, training with my G20 fitted with a .40 S&W barrel will make for (really really!) cheap training.

I know Lone Wolf Distributors has these barrels as does KKM.

Anyone has any experience doing this conversion? Any experience with those barrels?

I understand from my limited Internet research is that loading a G20 magazine with the shorter .40 S&W ammo will not cause any feeding problems. I may have to fiddle with the recoil spring; it still has its OEM spring.