M&P Lore

In the before time...

There were once so damn many variations on the M&P it got tedious to keep them straight.

This leads to real work replacing or upgrading things.

Originally you had the option of having an external lock, or not.

You could have a magazine safety, or not.

You could have a thumb safety, or not.

If you chose the thumb safety, you couldn't choose the external lock (and vice versa).

This led to there being two frames*.

One that could accommodate the lock, one that could accommodate the thumb safety.

This led to there being three sear blocks.

One with the lock, one without the lock and one for the thumb safety.

Each of the three variations could come with a magazine safety as well, so a total of six assemblies.

Confused yet?

It gets better.

If you your gun didn't come with the external lock or thumb safety you also got a little plastic plug that filled the key hole in the frame.

None of this would matter in the slightest, but S&W upgraded them in 2009 or 2010 or so; bringing the count to 12 variations!

They changed the size of the sear plunger and put in a stronger spring.

This STILL doesn't matter unless you try to install an Apex Tactical trigger and/or sear.  You need the newer, larger plunger for those kits.

Happily, Midway will sell you a no-lock, no-magazine safety block and a no-lock, yes-magazine safety block with the larger plunger.  They will not sell you a thumb safety block.

It looks like Midwest Gunworks will sell you any variation.

Nowadays...

Gone is the very unpopular external lock.

S&W only makes one frame* (the thumb safety variation) and two sear block assemblies (also the thumb safety version).  If you don't have a thumb-safety, you'll have two filler plugs where the safety enters the frame.  The difference in the sear blocks is whether you have the lever for the magazine safety.

The safety can be installed in either, sometimes it is from the factory.

* Per frame size that is.  9mm/.357SIG/.40 and .45; Full size and compact...