Okay, so on Sunday I break out the 20SF, 200 rounds of Underwood 180 grain fmj, and head to the range with my 17 year old son.
I shoot a mag of Underwood with no problem. I had forgotten how much recoil and blast this stuff had. It sure turned some heads on the range! I give my son a mag, and he attempts to fire it off and has several misfeeds. I ask him if he is limpwristng, and he says "maybe." So I switch out the mag, even though I have never had trouble with that mag before, and let him try again. Just as an aside, my son is a 6 foot 3 inch former wide receiver on his high school football team, and is a lot stronger than his old man. He gets through a mag with no problems, and then I try again. The gun then malfunctions for me. Long story short, I relaxed my wrist and the gun worked. I tightened up again and the gun failed. I run a 20 pound stainless recoil spring, and have fired Underwood ammo previously without this issue. My son had multiple malfunctions the whole shoot.
I am thinking this is more of a gun issue than an ammo issue. The thing is, it isn't right that I have to relax my wrist in order to get the gun to cycle properly. Quick followup shots are a must in a combat situation, and this is the way I was trained. I think the slide is slamming on the frame and is causing some frame flex.
Thoughts?
Well I do read where a lot of people with the G-20 who have changed their springs have also had issues just like what you are expericing. That being said, someon mentioned the springs (round wire) were bunching up causing drag on the slide. They swapped to the flat wire springs and problems went away...I believe they used the ISMI recoil system.
Some have started using the new Gen 4 system with good results...
I think this is considered a flat spring?
http://glockstore.com/pgroup_descrip/7_Custom+Parts+%26amp%3B+Accessories/2138_Stainless+Steel+Guide+Rod/?return=%3ftpl%3Dindex%26category_id%3D7%26_Custom%2BParts%2B%26amp%3B%2BAccessories%2F
Other than that, this spring works great with Hornady 180 XTP and even PPU.
That is a flat spring.
Okay thanks.