That is the trouble with making mags work. There is also the issue of hold open depending on how you run your equipment. You can mic and draw a print and get the pattern down, and still mess up. So it can become more costly than just getting the right mag to start with. But I get it and undestand 100%

 

I don't own any Ruger or Glock pistols but I do own a couple of M&P's. I'd like to have magazines that would interchange between carbine and pistol. If it wasn't for that I'd probably just buy a couple of Ruger mags and call it good.

 

I have done the mod with both M&P mags and CZ mags. I got a couple of M&P ProMags to experiment with and I did get them to work fine.

I think a tool to punch the slot in the mags would be possible.

Feed fine and last round hold open works.

 

I'm in the same spot, have many M&P mags and use that gun for carry and competition and have no desire to buy special mags for another gun.

Can the magwells provided for Ruger and glock mags be used as a guide to make an M&P mag well for the PCC?

Seems like a 3D printer could spit them out easily.

 

Seems like a 3D printer could spit them out easily.

If you can do that, let me know.
The best I can do is an assembly with 3D printed and traditional parts.

 

I successfully modified 5 M&P mags to fit the PC9 Ruger mag well. I used the included Ruger magazine as a guide to position the top of the slot accurately as it’s the only surface that matters. In fact my slots were not as uniform as my obsessiveness would have liked but they all worked great.

The biggest challenge is the steel used in the magazines is very hard, as it is pressed metal. I had to find a cobalt drill bit and used cutting fluid to even put a dent in the steel. Once you get the hole, patiently take a square needle file (cheap set from harbor freight works) To shape and size the slots. As the slot is longer that wide, the flat needle file worked great at smoothing the sides of the slots.

Yes it was a pain initially because of the hardness of the magazine steel. But with the right tools it is possible. Unfortunately I’m not sure I have any photos, I sold that M&P a short time later. 🙄

 

I successfully modified 5 M&P mags to fit the PC9 Ruger mag well. I used the included Ruger magazine as a guide to position the top of the slot accurately as it’s the only surface that matters. In fact my slots were not as uniform as my obsessiveness would have liked but they all worked great.

The biggest challenge is the steel used in the magazines is very hard, as it is pressed metal. I had to find a cobalt drill bit and used cutting fluid to even put a dent in the steel. Once you get the hole, patiently take a square needle file (cheap set from harbor freight works) To shape and size the slots. As the slot is longer that wide, the flat needle file worked great at smoothing the sides of the slots.

Yes it was a pain initially because of the hardness of the magazine steel. But with the right tools it is possible. Unfortunately I’m not sure I have any photos, I sold that M&P a short time later. 🙄

Curious could you still use the M&P mags in the Smith once they were modified?

 

This is not a great photo but you can just make out the slots at the top of the photo. You might also detect a little square shaped paint touch up around each one.

 

Thans so much. Lots of help here. I do have one question though. The top front of the Ruger mag (above the slot) looks like it has a small tab sticking up whereas the M&P mag is flat. When you measured for the slot did you measure from the top of the tab or the flat part of the mag (I hope this makes sense)? Thanks.

 

Here are some pics of the modified M&P mags.

Left - unaltered M&P mag, then 2 modified mags and on the right an SR9 mag. Even the one with the ugly one slot works.

SR9 mag

Modded M&P mag.

The SR9 mag was .7155 inches from the top of the tab to the top of the slot.

My modified mags ended up being .7335 inches from the top of the mag edge to the top of the slot.

I started a bit low and enlarged the slot upward until it fit into the PC Carbine and manually fed dummy rounds.

If you put a round in the mag and measure from the center of the round to the top of the slot they are the same distance, so the M&P mag follower is just a bit different than the SR9?

In a previous post I wrote that I had to remove some material from the mag where it hit the ejector, I was wrong. I had to do that to the CZ mags I modified. I edited that info out of my previous post.

I made a template with some plastic material and used that to mark the mags.

 

Great thanks. That's what I needed to know. Again, thanks to everyone for their help.

 

Hence, the reason I favor the P Series Pistols and the 1st Generation Police Carbines................

 

Because M&P magazines fit without modification?

I have seen one at the range and it's a very nice gun, but they don't make them or the pistols they were meant to be paired with anymore, so they are a bit hard to find.

 

Does the LRBHO work with modified M&P magazines when using the SR9 magwell with the stock transfer bar (pawl)?

 

ProMag now makes a 50 Round for the PC9!
Nice one to try..
Ruger® SR9® 9mm (50) Rd - Drum Black Polymer