HKPRO Forums banner

O-ring won't stay in place

3769 Views 10 Replies 8 Participants Last post by  Ed L

I bought a used HK45 that came without the green O-ring on the barrel.

I ordered some O-rings and they came in black, which is listed as working for the HK45.

But when I manage to slide them into their notch in the barrel, they do not stay in the notch once the barrel is in the slide. They slide out of place and all around the barrel.

This occurs whether I put them into the notch in the barrel and then slide the barrel into the slide, or if I slide the barrel into the slide without the O-ring, let the barrel protrude a bit, and then slide the O-ring into its notch. As soon as I move the barrel back in the slide, the O-ring slides out of its notch.

Any ideas?


In fact, the barrel with the O-ring in
1 - 11 of 11 Posts

· Banned
112 Posts
If the barrel has a serial # matching the pistol frame, then you can send it to H&K for warrantee/repair work. If the barrel is a replacement or aftermarket, the bore at the front of the slide might not be machined open enough to allow the O-ring. Some O-rings I have seen are green in color and might be a thinner O-ring. You can call H&K in Georgia and tell them your serial #, then buy some O-rings from them they say were issued with the pistol if that is the case? If they say that your pistol wasn't issued with a O-ring barrel, you have the answer!

I hope this helps...

· Registered
242 Posts
Discussion Starter · #4 ·
Thanks, LMKnucklehead,

The barrel and the serial number of the gun match, so I don't think it is a replacement barrel.

The barrel does have the slot for the O-ring.

If it is any difference, the gun is an American made HK45 full size.

· Registered
1,245 Posts
I would get a nylon like brush and clean around where the o-ring goes, then do a good cleaning around(inside the frame) where the barrel goes thru the frame. Might have a very small amout of most anything pushing it off. Plus i put a small amount of oil aound the ring as Dare said, good luck...
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.