Feeding jams w/ 1.2 OAL .40 w/ K10 (10mm) mag

[jmbaccolyte]

Fired my new Witness Match with 1.135" OAL .40 S&W ammo and the K40 magazine and it fed flawlessly. I then tried 1.2" OAL .40 S&W ammo in a K10 magazine and it fed about 70% of the time. On the ones that didn't feed properly, there was a gouge on the flat nose of the bullet but it didn't appear to have nose dived into the feed ramp. Maybe it went too high. Was the K10 mag spring just too strong or do I need to adjust something? I put the .40 follower in the 10mm magazine, but it didn't seem to change anything. I was running the recoil spring the gun came with and the long OAL load recipe was a 155 gr truncated cone lead alloy bullet with 5.4 grains of WST fired at about 30 degree temperature. The recoil felt milder than factory loads and milder than the control 1.135" OAL with the same bullet and 5.0 grains of WST and fired at the same temperature.

Edited February 10, 2012 by jmbaccolyte

[dover0020]

To start maybe just try a 1.180 OAL. That may save you some time rather then trying out a bunch of different spring combinations.

[jmbaccolyte]

Thanks, I'll try that. Probably won't get to it until this weekend though. I'll report back w/ the results.

[CHA-LEE]

The K10 magazines are very different than the K40 version. The K10 magazines probably require an OAL that is very close to stock 10mm OAL which is 1.260.

[jmbaccolyte]

Thanks, I'll try that. I appreciate the help guys. Should have a report back by Monday.

[jmbaccolyte]

I tried adjusting the over-all length (O.A.L.) as you guys suggested and it worked. Thanks. I tried 1.256" as Cha-Lee suggested and it fed great. I ran 50 rounds at that length through it w/o a hiccup. I appreciate it guys, Thanks again. Prior to this I couldn't run half a mag w/o a jam.