I'm saying either slower ammo or lighter round. I have a .22tcm9r Glock 17 barrel conversion that sends a 40 grain projectile from a 4 inch barrel at 1800-2000 fps at a massive psi jump over the typical 124 grain 9mm rounds. But if you run the same spring, it wont cycle because the lighter round isnt providing enough recoil against the spring. Have to use a lighter spring. edited for typo
Subsonic ammo is heavier than supers. It isn’t weight that is the issue but rather the amount of gas provided by the cartridge.
I'm saying either slower ammo or lighter round. I have a .22tcm9r Glock 17 barrel conversion that sends a 40 grain projectile from a 4 inch barrel at 1800-2000 fps at a massive psi jump over the typical 124 grain 9mm rounds. But if you run the same spring, it wont cycle because the lighter round isnt providing enough recoil against the spring. Have to use a lighter spring. edited for typo