View Full Version : p220 no lock open on empty mag

July 02, 2017, 10:18
So the p220 I snagged from the market place arrived yesterday... mag only rarely locks open when empty, either when firing or racking the slide manually.

From searching, aside from operator error (I'll be looking at that as well..) it seems a cause is the mag release return spring being too stiff or something along those lines, and a phone call to SIG will get a new spring.

But... is this a thing I can swap out myself? Any special tools required? Any links to a good parts diagram, or perhaps a video with a full detail strip?


July 02, 2017, 14:38
yes, you can swap it out yourself. Requires removal of breech block & pin and breakdown lever, which can be a little tricky until you get the hang of it. Breakdown lever removes by pushing right to left while rotating. Key (literally, a keyway) is that the pin is slotted for the legs of the breech block, so the block installs diagonally to line up with the slots on the pin. There should be a slot or serrations on one side of the pin (21) which will help determine orientation. I usually have the pin turned upward just a tad to catch the legs, and it straightens out as it drops in.

The slide stop spring (19) has a little dogleg that connects to the side of the breechblock (17) and the back end sits on top of the slide stop, applying downward pressure (18). It also puts tension (the downward curve in the middle) on a small flat on the breakdown lever (16).

Image is a 226 but principle is the same.


July 02, 2017, 15:17
Maybe try a good ultrasonic clean first, might just be years of accumulated impacted crap causing the problem

July 02, 2017, 15:23
Years ago I had one of the first SIG 220s imported, which was brought in by Browning as the BDA. It would not lock back on an empty mag because the mag spring was too weak. The BDA I owned was in .45ACP.