Conversion 40/9mm

[SD]

I owe a friend who has been helping take care of our home since we moved, he will not take any money. Knowing he has always wanted to convert his Gen 4/23 to 9mm. I ordered him a Alpha Wolf conversion barrel, information from LW states using a conversion barrel in a Gen 4, may cause feed issues without replacing recoil spring. I added a G-19 replacement spring to the order. Anyone know if this is truly an issue, and will the 40 cal magazines work with the 9mm ammo? thanks

[HCM]

I've had good luck running 9mm out of SIG and Beretta .40 mags but Glocks need 9mm specific mags in my experience.

[Nephrology]

In my experience with a KKM 40-9 conversion barrel in a Gen 4 Glock 35, the gun would not run reliably with the .40 caliber recoil spring. I also found it still didn't run exceptionally reliably even with a 9mm recoil spring (admittedly this was with Wolf 115gr ammunition), but certainly better than with the .40 cal spring.

I've heard good things about Gen 3 .40 cals running reliably with conversion barrels, but based on my experience with my G4G35 I'd reserve the 9mm barrel for inexpensive practice and carry it with the OEM .40 caliber barrel.

[Paladin]

I've got a gen 4 glock 32 with the same conversion barrel for 9mm and I ran it with the 357 spring and then bought a 9mm spring just to see if there would be any difference. The only thing I noticed was better more consistent ejection but I didn't have any failures with either. I did experience some brass to the face with the heavier spring. As always YMMV.
Rick