CZ 40 caliber P07 recoil spring update. Started this post when I couldn't (and still can't) source a 40 caliber P07 OEM recoil spring (either uncaptured spring or captured versions). I had acquired 2010 date used gun. The previous owner had provided some moderate (180gr 400'# muzzle energy) ammunition which was ejecting spent cartridges around 10'. My intended ammunition was hotter (165gr 480'# muzzle energy) and thought it made sense to replace it.
After trying to decipher the inputs from my question regarding recommendations for moderately hot ammunition, I sourced an 18# CGW and a 20# Glock 23 IMSI flat wire recoil spring along along with solid guide rod as the best available options to get a feel for what spring to use.
What I've found so far is the 18# CGW spring ejects just like my used 40 caliber spring and the 20 glock spring is quite a bit stiffer (3' ejection with moderate ammunition and 5+' with 165 gr ammunition. The glock spring seems to be ok as it doesn't go solid as the gun cycles even though it's intended for a 4" barrel pistol and has 1/4" more initial compression when installed in my P07. A better overall choice may be a 17# Glock 23 ISMI flat wire spring to tolerate milder practice ammunition. My try it when I finish tinkering with the pistol's action. Thks, Larry
