View Full Version : M&P sport lower

05-30-2012, 11:48 PM
Hey all. I have a question that may seem dumb but I know nothing on building an AR. I'm going to be purchasing a smithy sport fairly soon and my question is as far as swapping an upper is it just as simple as just installing it? (Assuming its the same cal.) What type of work is involved (if any). Thanks guys.

05-31-2012, 12:21 AM
No work at all!

Maybe you lose a sixteenth of a calorie pushing in the 2 pins that hold the 2 receivers together. Lemme see if I could find a picture:

Just push 2 of these with your finger or tool


05-31-2012, 12:24 AM
As far as i know there is nothing different about the sport lower than any other .223/5.56 lower. So using it with another ar-15 upper should be fine. Simply pull out the take town pins and swap the upper with whatever you want.

05-31-2012, 12:36 AM
Awsome! So my next question is are the sport lowers the same as their standard m&p? Meaning would they be a good lower to build on?

05-31-2012, 12:42 AM
Worst case scenario, you might have to get a different weight buffer, but highly unlikely, and not at all difficult a procedure.

IMO, the barrel that comes with your Sport sounds pretty good. If you're worried about not having a forward assist or dust guard, you can pick up an upper receiver later for around $100 or even less, then have a shop swap it out for around $50.

05-31-2012, 12:45 AM
Awsome! So my next question is are the sport lowers the same as their standard m&p? Meaning would they be a good lower to build on?

Might actually be better then others. I think the only thing that you have to worry about, if it matters to you, is voiding your warranty with S&W. Usually not a big issue, but they do offer one of the best warrantys in the industry.

05-31-2012, 12:48 AM
The quality of the lower really doesnt matter in most cases. The difference between Joe's stripped lower and Blackwaterfall Daniel Security Voltomus prime lower is purely cosmetic.

The only strange thing ive seen in some california lowers was the bottom of the magwell being closed (topload only). As far as other S&W lowers... they are literally identical and work great.

05-31-2012, 1:52 AM
What about the bb? I hear smithy voids the warranty if you swap the bb for an aftermarket is there any truth to that?

05-31-2012, 1:57 AM
Every manufacturer pretty much says you void your warranty when you shoot reloads. How will they know if you swapped BBs? It's so easy to swap back and forth without any evidence of doing so.

I don't have a S&W manual, but im prettyyyyyy sure you can change out the BB without voiding the warranty. Is the reason to change to a convertible bb? Theres a dangerous line when you dont have a BB on a complete featured rifle.

05-31-2012, 2:52 AM
No I don't plan on removing it. I just like knowing what's a deal breaker with smithy lol

05-31-2012, 8:54 AM
The only thing I've seen different on the M&P Sport lower is the trigger guard is one piece and can't be changed.


Not really a deal breaker since itís a good size.