I just learned that Mark II mags can be made to work in a Mark 1. I've used Mec-gar mags in my CZ without issue, but was curious if anyone has used the Mark II Mec-gar mag specifically - especially in a Mark I - and what your thoughts are. It's cheaper than the apparent factory mags and reviews I've seen seem generally better as well.

For anyone interested, I went ahead and ordered two of these. Just received them and I can confirm that they fit and eject just fine from my "A100" Ruger Standard. I have not used them yet so will have to wait to see if they feed reliably.

I cannot compare them to Ruger Mark II mags as I don't have any, but compared to the mags that came with my Standard these are pretty cheap feeling. Base and follower is plastic (mine are metal) and the frame even feels thin. If they work then for $15 I guess I can't complain.

I seem to be having a conversation with myself, but in case this is helpful to anyone I finally tested these Mark II mags in my Standard. They fit fine and functioned fine with a couple small issues. One of the mags did stick and I couldn't get it out. Might have been due to the cold as it came out fine at home. If there is a way to smooth these up that would be great so I'll have to do some research. Also, I did have one FTF when it didn't pick up the next round (bolt closed on empty chamber). Might be just a break in issue. Since the mag stuck I wasn't able to put more rounds through.

Long story short, Mec Gar Mark II mags work in a Ruger Standard (mine is not marked Mark I) but maybe not as flawlessly as the factory 9 shot mags.

Thanks for the information.

Bought a few of the MkII mags and flipped the thumb stud to function in my Standard.
Only had one that was wonky and looking, a feed lip was bent downward too far... perhaps dropped or bashed in shipping.
I lifted it out with a round file to match the rest of my mags, and GTG.

Now my little Standard/Mk1 has a good supply of mags that work.

I love that thing.

I’ve been looking at the Mecgar mags for my 22/45. Price sure seems good.

I have been using a couple mecgar mags in my mark III 22/45.  Been impressed so far, they have been solid.