G34 Gen 4 recoil spring

[Mickael81]

Hello Calguns,

Question:

I have a G34 MOS Gen 4 with approximately 1,000 rounds down the barrel.

Every 100 or so rounds, my slide does not go all the way forward and puts the gun out of battery. At first I thought I was riding the slide with my support thumb causing my own malfunction but that’s not the case. Neither are the magazines.
I’m running the gun stock with an RMR.

I figured I need to get a new recoil spring.

Should I be getting a heavier spring or lighter if out of battery is the issue?

Suggestions on brands?

Thanks in advance.

[9Cal_OC]

Maybe get another OEM spring to compare.
Although if it’s every 100 rounds, doubt itd be the spring. It’d be more frequent if that.

[Snoopy47]

How badly is this "out of battery" situation?

I ask, because, I can duplicate a similar situation with my 17 and 34?

Is it not going into battery upon recoil and the slide slamming forward while picking up another round, or is it not going into battery when you let the slide move forward slowly.

If it's not going into full battery after a shot was taken and the slide is slamming forward after recoil, yea, that's a problem.

My springs have way more mileage on them than 1,000 rounds. So I'd just recommend another OEM spring. Otherwise you now run the risk of needing hotter ammo to run the gun, and that might limit your ammo selection which is not all that easy in today's world.

[k1dude]

I'm surprised the problem appeared after 1,000 rounds down the pipe. Usually the problem happens with brand new guns. I've personally had that problem with new guns. Breaking it in sometimes helps, and sometimes you just need a new spring. I had a new G26 gen 4 with that problem, and the problem went away with a simple spring swap.

If you don't want a gen 4 double spring/guide rod, you can always use a gen 3 setup in your gen 4 with the use of a recoil assembly adapter ring which costs about $10.

[Mickael81]

Thanks for the advice.

I’ll swap the recoil spring with another OEM spring and run a few hundred rounds to see what happens.

BTW. When it’s out of battery, there’s a new round in the chamber. The slide is not fully forward so I have to tap the back of the slide to get it into battery… like the spring didn’t have enough power to finish the job or something.

[Snoopy47]

You mean from a full lock back (and finger off the trigger) the slide will not pick up and fully chamber a new round when the slide is released forward and slams closed?


I might also consider the extractor in the slide. It might be getting hung up on the rim of the case.