Just The Facts Ma'am, Just The Facts
1:7 twist rifling. Chrome lined barrel and bolt carrier. HP and MPI testing. The M&P Sport has none of this
.
Not exactly:
The Sport has the same chromed carrier & HPT/MPI bolt as the rest of the M&P-15 line.
The Sport has 5R 1:8 gain twist rifling, and it will still 77gr rounds accurately. The gain twist rifling also allows it to shoot lighter construction bullets at higher velocities than a constant 1:7 or 1:8 twist barrel. According to LWRC's testing their black nitride barrels have exceeded their hard chromed barrels in terms of wear resistance. (The same company that does LWRC's black nitride does S&W's black nitride, which S&W calls Melonite.) The Sport has a Melonite bbl. No, it's not chrome lined, but it's not a cheap barrel by any means either.
It also doesn't have a dust cover, bolt assist, or the ability to change trigger guards
According to Hilton Yam's blog he was testing a Noveske prototype lower with an integrally forged trigger guard. The trigger guard on the Sport lower has the same wide, gloved finger opening that the MagPul & similar aftermarket trigger guards provide. Vltor offers their Modular Upper Receiver (MUR) in two configurations - one with, and one
without forward assist. If you must have the dustcover & forward assist, then you can get an upper for $100 or so. My local shops will move everything over to the new upper if I buy it from them. Even if your local shop wont it's a job that takes less than an hour. Figure $35 for the standard one hour minimum shop time fee if you have to pay for it.
Overall, you could still get the Sport with a FA / Dustcover upper installed for $65+ less than the Spikes.
On the other hand, if Spikes is using the materials & doing the testing they claim, then they're a great buy for the money. The complete Spikes upper I recently handled at my LGS was very nicely assembled.
Almost anything is better than a S&W M&P sport....
The Sport is better than the standard offerings from the following companies, and I've listed the reasons.
Rock River - no HPT/MPI bolt, gas key not properly staked, RE castle nut not staked. 1:9 twist standard, faster twists optional. Chrome lining optional, nitrided bore & chamber not offered.
Olympic - same as above
DPMS - same as above.
Bushmaster - chrome lining standard, otherwise same as above.
Stag - must order "plus package" to get 1:7 twist, HPT/MPI Bolt, and M4 feed ramps.