Hi.  I decided to take apart my Sig P228 tonight for a detailed cleaning.  I striped down the frame completely.  All went well accept the magazine catch.  I put the magazine catch detent in wrong.  Now the magazine catch does not work and I can’t get it out to fix it.  Damn!  

The detent holds the mag catch in.  It has a shoulder on one side like a half-sphere.  I put the shoulder facing to the right if you are looking at the gun from the muzzle.  It goes in facing the left.  What can I do aside from pounding the whole thing out and ruining my frame?  There must be others out there that have done this.  Please help.  Thanks.  

now if i understand you correctly you pushed the entire mag catch stop pin (part #46, that holds the mag release in place) into the frame? I've never done that with mine beforebut i can see how it could happen. I'm not sure, but could you remove the support plate (part #44) and pull the mag release out that way? If not, you can order a new mag release from sig for about 24 dollars... I'm not sure how comfortable you feel with drilling out your jammed mag release, but a titanium drill bit in the middle of the mag release button only needs be about 1.5 to 2 millimeters deep to disrupt that little catch stop spring. (part #47) after you drill out the spring, that  little pin wont have the pressure it needs to hold the mag release in place... that's the only thing i can think of.  If all else fails, i'm sure the sig gunsmiths could find a way to fix it. Good luck.

Yes you have the situation correct.  The mag catch detent is fully behind the frame.  I am going to try getting it out using an automotive feller gauge.  If that does not work drilling might be a possibility if I can find a replacement mag catch.  Thanks for the help.  

I poped it out useing a very thin feeler guage and a few taps on a hammer.  Thanks SIG fourms