Few years ago I bought a S&W 15T it's a super nice rifle, Troy rails and Troy BUIS.
Like many back then I ordered a few of the new MAGPUL-P Mags to try. The ones I received none of them would not lock into the S&Ws Mag Well.
I called MAGPULs Tech. support and the person I spoke with just informed me it was my S&Ws Mag. Well, and I needed to grind it out to fit the MAGPUL-P
Mags. I asked this person if they would like to inspect my MAGPUL-P Mags his answer was no it's not our problem.
My metal AR-15 Mags fit and drop free so I wondered what is the real deal.
Well I called S&W and spoke to the AR-15 project Engineer he said there was nothing wrong with the S&W Mag Wells they were made to meet the Military Spec. for metal AR-15/16 Mags.
Well I again called MAGPUL and spoke to their Clark Drake he is their sales guiding light.
We had a good talk with him defending his Mags and pointing the problem at my S&W. at some point in a few calls with him things got nasty, with him telling me tpo not ever call him or MAGPUL again.
It really did not pertain anymore with the Mag well fit of my S&W it got down to my feelings that MAGPUL-P Mags are nice range Mags if they will fit your AR but they are not a Defence or Combat ready AR15/16 Mag.
IMHO a Mag must have metal feed lips to be a Defence or Combat ready Mag.
Well Mr. Clark Drake really gave me a dressing down and since hes had me banned many times over from a lot of AR forums.
So much for the MAGPUL-P Mag thoughts.
Now on to S&W and their AR-15s. MAGPUL contacted S&W and got S&W to start opening up their Mag Wells so to fit the many over sized injection molded MAGPUL-P Mags they were getting produced, this being cheaper then addressing the real problem of their MAGPULs quality control problems.
Today S&W is in full bed with MAGPUL using their Rails and their BUISs, I guess when you have deep pockets you can buy yourself into any Company.