K31 bolt a bit clunky.

[2meterB]

Got my K31 the other day.

Bolt stuck pretty bad, so I tore the bolt open and cleaned/lubed everything. Used CLP on the bolt pieces, and grease where the bolt contacts the receiver.

The initial pull sort of just "clicks" back slightly, then takes a lot of force for the initial pull/cocking of the gun. Enough so that the bolt slams back hard into the open position. I worry for the operating rod.

Have read a bunch of stuff on google, most just suggested the steps I've already taken.

Maybe I just have a clunky bolt, or an incorrect perception of how it is supposed to operate?


Haven't fired it yet. maybe it just needs some rounds through it.

[SanPedroShooter]

I assume the bolt matches.

My wild *** guess is it sounds like a issue with the spring in there. Or something...

When you pull back on the handle, the bolt should rotate unlock and the firing pin spring should be compressed. Something is hanging up in there.

Can you easily take the safety off and on?

[2meterB]

It matches.

Bolt moves back about a quarter inch then hangs up and has to be jerked past that.


Safety is heavy but operates ok.


Closing the bolt is easy.

[SanPedroShooter]

Try this. Pull the cocking ring all the way to the rear until it clicks without opening the bolt. Then work the handle. It should be smooth with a slight hang up as the bolt unlocks.

[SanPedroShooter]

That hang up is the spring compressing. Its normal. Get used to working a straight pull and it should get smoother.

[knucklehead0202]

In my experience all straight pulls require a bit of a snap to open. I have a k31 and an m95. You don't just gently pull backward, you grab and kinda yank it, not too roughly, but like you mean it. These are rifles, not china dolls, you won't hurt them.

[2meterB]

Hangs up even with the ring pulled

[SanPedroShooter]

Yup^ I agree. Give it a forceful pull straight back. It'll go.

[SanPedroShooter]

Does it hang up less with the ring pulled all the way to the rear? It should be slightly smoother as you have put tension on the spring.

Yours might be a little sticky. Give it a work out. Also, its my experience that shooting it in the field is different than working the bolt in your living room.

Give it a smart straight pull directly to the rear.

[2meterB]

Same effort either way...


All right I'll be a little more rough with her. Zygomatic bone gonna take a beating.

A thread I found on another site had me worrying about the rod.

[SanPedroShooter]

I suppose the rod could tweak if you were pulling at an angle.

Take all the ammo out of the room.

Put it to your shoulder and pull it and dry fire it.

That'll give you the feel of whats it like to operate it normally. My 31's are a little sticky. My 1911 is smooth as silk

[Guisan]

What kind of lubricant are you using on the operating rod lug ?

[2meterB]

Slip 2000

[SanPedroShooter]

This is an old Moss Pawn video of a shooter working the bolt on a K31. Watch Hickok45s K31 video too. You'll see the hangup, but they just pull through it.

[Guisan]

Slip 2000 is a fluid and too thin, use a grease instead as that will improve operating the bold.Best choice is a chromium molybdenum grease or Automatenfett and just put it on the lug.