Hopefully your not shooting premium self defense JHP bullets and are shooting target JHP bullets but that is neither here nor there in the discussion.
Can you expand on shooting Premium SD JHP ammunition out if a TSO?
Do I need to consider going to a 18# spring using SD ammo? ~ 182 PF by manufactures specs, I haven?t actually ran it across a chronograph yet.
My comment was aimed at the cost of shooting a premium SD bullet vs a target JHP bullet. The TSO is a competition gun so not many rely on it for self defense or CCW. If it is your CCW/night stand gun, then by all means shoot your favorite SD bullet (at the premium cost). The gun doesn't care, your pocket book cares
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Tune the recoil spring the same as any CZ, if the brass is landing 6-8 feet (in my experience for CZ in 40 S&W, 8-14 feet) and ejecting consistently then it is good to go. If the distance is shorter lighten the spring, if farther increase the spring. You should also be concerned on your splits for follow up shots. A heavy spring will cause the pistol to dip upon returning to battery. I shoot 170 PF and use the 16 lb spring because of muzzle dip with the 18 lb spring.
Cheers,
Toby