[bblr]

I'm guessing you already got the mag catch out? If so, then remove the right grip panel. Remove the trigger bar spring. You'll see the support plate has a little nub right in the middle. I take the sig armorer's tool (or a flathead screwdriver) and push on the nub rearward. It will slide back and out of the groove it's in. Try and keep the screwdriver inline with the pistol as much as possible. It usually slides out relatively easily. The metal here is very thin and you don't want any force exerted outward. You only want force rearward.

Insert in the opposite direction.

 

[Bulljack]

Hi bblr. No , I have not removed the mag catch yet. How do I do that? Also, do I need to remove the trigger bar spring so I can fully remove the support plate? In the pic you posted, the spring looks like it could obstruct the support plate as it is moved back.

 

[ThnkFrst]

The mag catch removal/installation is described and demonstrated in this post: http://sigtalk.com/sig-sauer-pistol...stols-how-they-work-animation.html#post255779.

Use a pick or your SIG armorer's tool small bit to depress the mag catch stop and slide the catch assembly out of the frame. Be very careful when doing this as the catch stop and catch stop spring will want to launch once they clear the frame never to be seen again (unless they wind up in your eye). Putting the frame inside a clear plastic bag when doing this is advised to avoid loosing these very small parts.

Use a screw driver positioned on the peg on the support plate to push the plate to the rear of the frame and remove it. A few light taps on the screw driver should be enough to drift the plate out of the frame grooves. Yes, the trigger bar spring must be removed first.

Pay very close attention to the orientation of the mag catch stop when reinstalling; the long end goes towards the frame. If you install it with the short end towards the frame you will play hell ever getting it out again.

 

[Bulljack]

Great! Thanks ThnkFrst!

 

[bblr]

When reinstalling the mag catch stop you MUST put it in correctly or you will not be able to get it out again.

This is the correct orientation for reinstalling:

 

[RLevinson68]

When reinstalling the mag catch stop you MUST put it in correctly or you will not be able to get it out again.

This is the correct orientation for reinstalling:

So very important. I picked up a frame with the catch stop installed incorrectly and now the only way to get it out is to drill through from the other side of the mag release. So thrilled about ruining an original German P228 part.

 

[Bulljack]

Btw, is the support plate hard to drift out? Can it be done just by pressing the thumb against it to move it out of the grooves?

 

[bblr]

Btw, is the support plate hard to drift out? Can it be done just by pressing the thumb against it to move it out of the grooves?

You might have to tap it a little but it should push out relatively easily.

 

[Bulljack]

You might have to tap it a little but it should push out relatively easily.

Thanks again!!

 

[Bulljack]

Is the support plate of the MK25 phosphate coated? How come it's not that corrosion resistant?

 

[Sterling Archer]

When reinstalling the mag catch stop you MUST put it in correctly or you will not be able to get it out again.

This is the correct orientation for reinstalling:

And for God sake don't let that thing pop out or the part and spring will both go flying across the room never to be seen again. Ask me how I know...

 

[Sterling Archer]

Btw, is the support plate hard to drift out? Can it be done just by pressing the thumb against it to move it out of the grooves?

Mine was incredibly difficult to get out and back in. Very tight fit.

 

[drPhibes]

And for God sake don't let that thing pop out or the part and spring will both go flying across the room never to be seen again. Ask me how I know...

I actually managed to find mine after a few hours, so all experience seems to indicate that it's easier to find than a S&W 586 rebound spring (which was lost for a few months). In general, when disassembling small spring loaded parts, do it inside a large transparent plastic bag. That will at least decrease the probability of it flying into low earth orbit.

 

[ThnkFrst]

Is the support plate of the MK25 phosphate coated? How come it's not that corrosion resistant?

There is a phosphate version of the support plate, P/N 1200016-R. I would expect that's the version in your MK25.

How badly is yours corroded?

 

[Bulljack]

There is a phosphate version of the support plate, P/N 1200016-R. I would expect that's the version in your MK25.

How badly is yours corroded?

I am seeing a little bit of rusting around the peg area base near the grip. Not that much but it annoys me. I usually brush a coat of oil on that area but after a while the rust comes back....

 

[ThnkFrst]

There's a couple of options I suppose. One being to replace the plate ($5 + shipping) with the P/N I mentioned. The other being to clean the one you have and touch the area up with some rust proof paint.

 

[Bulljack]

There's a couple of options I suppose. One being to replace the plate ($5 + shipping) with the P/N I mentioned. The other being to clean the one you have and touch the area up with some rust proof paint.

You read my mind. One other option that I believe would be doable for me on this side of the world is to have the plate refinished. What do you think?

I'd really like to have it replaced and be done with it but ordering Sig parts and shipping it here would be near to impossible....

 

[ThnkFrst]

I'd try touching it up first and see how that holds up.

 

[Bulljack]

Thanks will try that..