internal lock

I have a first gen M&P 40cal. I have a internal lock on the left side. How do I get a key?? I bought it new and it did not come in my case.
Other then that the gun is great.





Thanks Barry

Are you sure. It's been a while since I owned one but I don't remember the gen 1's having a lock. Or maybe I just never used mine and I've forgotten.

Some, not all, of the original M&Ps had frame locks. Like this:


You'll have to call S&W to get a key. They'll probably send you one for free as long as you have some kind of proof the gun is yours.

I would remove the lock if it were mine.

Yeah, call S&W and ask for a set of the little keys.

The ILS (lock) was an option in the early years. Most guns came without the ILS and with a plastic cap plug to fill the hole in the left side of the frame.

Here's a couple quick pics I just took (so excuse the lack of good focus, as I didn't take multiple pics to get the best ones ).

These are a couple of M&P 40 sear housing blocks.

The SHB on the left is from '07, and the one of the right is from a few years later, after they'd integrated the manual safety option into the regular line.

The '07 vintage ILS SHB also has a magazine safety lever, but don't be distracted by that difference. I took the pics to show how the ILS takes up critical real estate later needed for the manual safety, and it also affects ejector design. (The rail sections molded into the MIM SHB's, and in the plastic frames, later changed and the production vintages aren't interchangeable, but that's another topic. Serial numbers can tell the company which SHB will fit in what frame.)




You can see the large cylindrical space needed for the ILS. It's smack dab in the middle of where the manual safety plunger and spring needed to go in later guns. It also requires the tail of the ejector to be different, to clear the ILS space (I don't have an older ejector where I could find it to put it in the SHB with the ILS, for this pic).

FWIW, the ejectors in the older 9/.40's fit sitting against the L/side of the SHB, while the .45 and newer 9/.40 guns had a raised rail at the front of the ejector space to hold the ejector in place, as well as larger ejector pin that helped hold the tail. It made it easier on armorers to have the ejectors held in the SHB, so they didn't fall away from the side of the SHB while you were trying to install it in the frame.

Once the manual safety became such a high demand option by customers, S&W changed the "standard" SHB from the earlier design that would accommodate the ILS, to the SHB that could be used for the manual safety option. In guns ordered without the manual safety, the same SHB could be used, and plastic plugs of the appropriate color filled the diagonal frame cuts (black or tan).

I'd be surprised if customer service wouldn't just comp you the "keys" if you called them.

m&P isl plug filer

So I ended up getting one of classic firearms M&P 40 police trade ins for like 219 super cheap and there Detroit police trade ins.. the reason why I got one being a city in my home state just an hour away…anyway is this what the little plug you were talking about out is???I was wondering my self looking at it seeing the arrow and L and being it was larger then my normal S&W key was like how would I get something around it but seeing your comment makes sense so I assume this is one of those plug fillers?

Your suspicions are correct.

Just call S&W and ask for a couple. They'll send them in a few days. They're probably glad to get rid of them. I've done it a couple of times for revolvers. Same Key I'd bet. Local gun shop might have some around too.

2ToeRacing said:

I have a first gen M&P 40cal. I have a internal lock on the left side. How do I get a key?? I bought it new and it did not come in my case.
Other then that the gun is great.





Thanks Barry

Click to expand...

Check in the nooks and crannies and especially behind the foam padding.

As noted by @fastbolt above in his post from 2020, S&W made changes to the sear housing block and eliminated the internal lock (made provisions for a manual safety too and some other changes). However, S&W kept using the existing inventory of frames (my guess) and inserted the plug to block the hole.

Not sure when S&W updated the frame to exclude the hole and put in the notches for the manual safety. My 1.0 from 2013 does not have the hole. The Performance Center ones did continue with the hole for a while since they didn't come with a safety.

Note, 2toeracing hasn't been on the forum since 2021.