Bolt not locking to the rear

Greetings all,

Kriss bolt is not staying locked to the rear on the last shot. Also I have noticed I am not often able to manually lock it to the rear with an empty mag. Sometimes yes but with much effort. Its not always been the case. Since I have used frog lube is my only thoughts.

Please help, I dont want to have to sent it in.

Are you using a stock 13 round Glock mag or the extended 25+ mag? If you're using the extended mag, try a 13 rounder to see if that works. If it does, then it could be the spring in the extended mag not pushing the follower up strongly enough.

The bolt hold open issue... not sure. Did you get a bunch of lube on the catch?

Ok I just tried with the 13rd and bolt locked first try.
I've been storing my extended mags loaded. So the spring must be at fault. Can I stretch them out? They are still good right?

Yeah I would stretch them out a bit.

You might also want to check to be sure that there's nothing binding or catching inside the mag with the extension.

Can you elaborate on what you say may be catching inside extended mag? They are clean if that is a concern.
The springs seam to have a natural spiral to them, not sure if that is normal.

The age old question of storing them with rounds still has me wondering.

J3L wrote:Can you elaborate on what you say may be catching inside extended mag?  They are clean if that is a concern.
The springs seam to have a natural spiral to them, not sure if that is normal.

Well, we at least know that your bolt locks to the rear properly with the 13 round mags... so the issue has to be with the extension.

Either it's the spring that's now too weak and not putting enough force on up on the follower or something is keeping the follower from properly pressing up on the catch. Can you see if the follower moves freely lime in your 13 round mag?

Did you install the extensions or did you get them assembled?

I installed one out of 7. The rest were bought either from Kriss Store, local shops or gun shows.

I began stretching the springs. It immediately resolved 4 out of 7. The last three took much more stretching.

I wonder how long the lifespan is after all this man handling. The aren't old. I keep them clean and dry. Prob more than 1000 rounds down range across all 7 mags plus the small one.

Ho old are the extended mags? There was a change in the springs to a thicker gauge spring. So they used to hold 30 rds but now reduced to 25+. If yours are the thinner 30rd springs, maybe that is the problem?

I wish I could tell you with all certainty how old they are. Within a year in my possession. No telling how long they lived on the shelf before I got them.