Keyholes by Walther...

Shooting last weekend resulted in some problems with the Walther P22 after shooting about 200+ rounds. I had installed the 5" barrel and laser sight and we were having a ball with it.

It started throwing keyholes. I moved the target up to 5 yards, and it was still throwing keyholes.

We had run thru 150 rounds of Remington Thunderbolts, and bought some boxes of something or other from the range - the brand escapes me. As soon as the thing started keyholing I stopped, but hadn't had the time to check it out until today. The bore seemed partially blocked, and running a solid brass jag thru the bore resulted in this:

A thin hemispherical ring of lead had welded itself lightly to the bore. It popped out in a couple of pieces after a few smacks with the jag.

I've never seen anything like this before. I can see that something was shaving lead off of one side of every bullet fired, but how it started I haven't a clue. I'll be taking the pistol to the range again this week with Remington Thunderbolts to see what happens. The rifling seems to be OK, but I'll also bring a replacement barrel just in case I have trouble.

Strange. This has been a reliable and fun pistol within the limits of it's type, price range, and construction. After trimming down those internal 'ears' as discussed about two years ago, I've put thousands of rounds thru this thing without a problem. I wish I could remember what that off-brand of .22s was that we got at the range. It worked a beauty with the Thunderbolts...and is a pure blast with the laser.

We'll see.

Oh, and for other Walther P22 posts, search for Walther in the side bar. There is a range report in there. Mine is several years old, and I believe any design problems with the gun have been fixed. On mine, a pair of steel 'ears' connected to the trigger mechanism were gouging the aluminum slide and needed to be smoothed down with a dremel tool. No problems since then with gouging.

Update: Results of the cleaning are here.