The Smith & Wesson M&P 15T M-LOK



Never in search of a personal perfect $3,000 – $5,000 AR, if an AR can function reliably, if it can be repaired with off the shelf AR standard parts and if it can put 3 shots into sub MOA circles, I’m all set. I built a good number of unique AR type firearms in the past and had fun. I felt the satisfaction association with quality DIY projects. Now I buy good factory built ARs that suit my personal applications and apply minor tweaks and few accessories to best match my application. The S&W M&P 15T M-LOK is a good example of this type of established solution.

Living in rural Maine in dense woodland, shots longer than 200 yards are not anticipated. Subsequently, there is little consequence to minor velocity loss, due to the lightweight 16″ barrel. The M&P 15T M-LOK’s 1:8″ rifling twist stabilizes 223 Remington bullets from 35 grains through 75 grains.

M&P®15T Tactical with M-LOK®

Manufacturer Smith & Wesson
Manufacture Springfield, MA
SKU 11600
Caliber 5.56 NATO / 223 Remington
Semi Auto
Gas System
Mid Length
Mag Capacity 30 Round PMag
Barrel Length 16″, 1/2″-28 Threaded
Rifling 1:8″ 5 RH
Weight 6.7 Lbs
Overall Length 33.5″ – 36.6″
Stock Collapsible
Receivers 7075 Aluminum
Receiver Finish Type III Hard Coat Anodized
4140 Steel Black/Armornite®
Length of Pull 10.25″ – 13.5″
Accessory Mount Full Length Picatinny Rail
Trigger 4 Lbs. 2 Oz. Single Stage
Safety Rotating
MSRP $1189.00

My personal usage runs from 35 grains for small varmint loads to 62 grains for deer size game and security applications. For my purposes, a rifle of this type would not see 80 – 90 grain match bullets, however, some 90 grain match bullet handloads suggests these will stabilize with the 1:8″ twist as well.

While I have never run comparison tests to analyze and confirm, 5 R rifling is said to improve accuracy and reduce bullet deformation by not compressing a bullet between opposing lands.

Looking through a bore scope, and cranking a cleaning rod, I do believe the slope of the rifling land sides accumulates less fouling and is easier to clean. The barrel’s Black Armornite® finish inside and out has none of the cracking problems of chrome lined barrels.

Starting at the back end, the M&P 15T M-LOK gets a 6 position CAR buttstock. It is a terrific all purpose stock that locks up solid on the rifle’s Mil-Spec buffer tube. While not as adaptive to a shooter as one of the adjustable comb, LOP, CANT, tilt types with interchangeable recoil pad textures, I favor this simple buttstock with adjustable LOP which will accommodate a variety of shooting positions.

The lower receiver is a forged piece with an integral trigger guard. Unable to spend hours selecting just the right skull or confederate flag emblazoned aftermarket trigger guard, I will turn to sling selection for entertainment value.

No great surprise, the M&P 15T M-LOK’s control are exactly where an AR 15 shooter would expect to find them; safety, bolt catch, magazine release. The same applies to the bolt assist, dust cover and charging handle. The safety selector can be switched from left to right side for shooter’s preference.

The M&P 15T M-LOK is supplied with front and rear folding Magpul MBUS sights. Yes they are plastic, but they are precise, they are light, and they stow only one-half inch above the M&P’s Picatinny rail. The rear sight has two apertures; small if both are flipped up, large is the small aperture is folded forward. A Part II of this article focuses on shooting with these sights from a variety of positions, some intended, some not so much.

The run of Picatinny rail is 20″ long with reference numbered cross slots. The sights as pictured provide a 17.5″ sight radius. The sights can be folded flat with red dot or scope in place. The handguard is secured to the modified barrel nut with three hex head clamping fasteners. Inferred is that an owner is free to modify, update or adjust to suit. I like these smallish handguards and can do without those that imitate a radial engine.

The handguard that gave the M&P 15T M-LOK its name. Smith & Wesson describes this as a 13″, slim, modular, Free-Float Rail System with Magpul® M-LOK® Capability, which also forms a Picatinny continuum from the rear of the rifle’s upper receiver to the end of the handguard. A 2” M-LOK® Picatinny Rail Panel is also included. M-LOK compatibility provides mounting for: slings, bipods, tactical lights, alternative sights, auxiliary rails,  pistol grip, and Schwinn tube patch kits. Yes, I did make up that last one, but not by much.

A patented S&W flash suppressor caps the lightweight contoured barrel. Its job is to suppress muzzle flash and to diminish recoil. If you would like to read the 6 pages of technical definition and assertions, please see United States Patent 8418803 – publication date 04/16/2013. The flash suppressor can easily be removed to make way for other muzzle devices.

Good shooter…

No factory ammunition this time. It was either factory ammo or pay the mortgage… yes that is a shot at opportunistic ammunition manufacturers with 3x prices and not much of an overstatement. In any event, I redirected my pouting to handloads and came up with the standard set I use when evaluating ARs.

Warning: Bullet selections are specific, and loads are not valid with substitutions of different bullets of the same weight. Variations in bullet length will alter net case capacity,  pressure and velocity. Primer selection is specific and primer types are not interchangeable. These are maximum loads in my firearms and may be excessive in others. All loads should be reduced by 5% as a starting point for development where cartridges have greater than 40 grains in capacity and 10% for cartridges with less than 40 grain capacity following safe handloading practices as represented in established mainstream reloading manuals. Presentation of these loads does not constitute a solicitation for their use, nor a recommendation.

223 Remington
Firearm S&W M&P 15T M-LOK
Barrel Length 16″
Max Case Length 1.760″ +0.0″/-0.030″
Min- Max COL
2.125″ Min – 2.260″ Max
Primer CCI 450 SMR
Bullet Diameter 0.2245″ +0.0″/-0.0030″
Reloading Dies RCBS F/L Lee Crimp
Bullet Type  Bullet Weight
Net H2O
COL” Powder Type Powder Charge
Muzzle Velocity
Muzzle Energy
100 Yd
3 Shot
Hornady V max 35 27.3 2.125 Re7 24.5 3541 975 0.8
Hornady V max 35 27.3 2.125 H335 28.5 3567 989 0.8
Hornady V max 35 27.3 2.125 X-Terminator 28.4 3472 937 1.2
Nosler Varmageddon 35 27.3 2.125 Re7 24.5 3533 970 1.1
Nosler Varmageddon 35 27.3 2.125 H335 28.5 3581 997 0.6
Nosler Varmageddon 35 27.3 2.125 X-Terminator 28.4 3432 916 1.2
Sierra Varminter 40 27.3 2.175 Re7 24.0 3442 1053 0.9
Sierra Varminter 40 27.3 2.175 H335 28.0 3497 1086 1.0
Sierra Varminter 40 27.3 2.175 X-Terminator 28.2 3317 977 1.1
Remington PSP 55 26.1 2.185 AR-Comp 24.5 2955 1067 0.9
Remington PSP 55 26.1 2.185 BL-C2 27.5 3054 1139 0.7
Remington PSP 55 26.1 2.185 IMR 4198 21.0 2973 1080 0.9
Nosler Partition 60 25.9 2.260 AR-Comp 24.0 2859 1089 1.1
Nosler Partition 60 25.9 2.260 Norma 201 24.5 2844 1078 1.0
Nosler Partition 60 25.9 2.260 RS TAC 25.5 2989 1191 1.2
Winchester Power Point 64 25.6 2.260 AR-Comp 23.5 2702 1042 0.7
Winchester Power Point 64 25.6 2.260 BL-C2 26.0 2751 1076 1.1
Winchester Power Point 64 25.6 2.260 RS TAC 25.5 2848 1153 1.0
Sierra Game King 65 25.6 2.260 AA 2495 24.0 2716 1065 0.6
Sierra Game King 65 25.6 2.260 AR-Comp 23.3 2753 1094 0.9
Sierra Game King 65 25.6 2.260 CFE 223 27.0 2879 1197 0.4
Hornady A-Max* 75 24.8 2.390 AA2495 22.5 2480 1025 1.2
Hornady A-Max* 75 24.8 2.390 Re15 23.5 2462 1010 0.9
Hornady A-Max* 75 24.8 2.390 CFE 223 25.5 2687
1203 1.0
Hornady A-Max* 80 23.9 2.390 AA2495 21.5 2416 1037 0.8
Hornady A-Max* 80 23.9 2.390 CFE 223 24.5 2530 1137 1.1
Hornady A-Max* 80 23.9 2.390 Norma 203B 23.0 2502 1112 0.9
* Hornady lists these at 2.390″ COL, above SAAMI Maximum and too long to feed through a standard magazine


It seems when I began reloading 223 Remington ammunition there were a good number of compressed loads.Better powder choices, optimized for the 223 Remington round, have all but removed that issue.

Velocity may seem a bit low. Please keep in mind the S&W M&P 15T M-LOK 16″ barrel.

As has been the case in previous reloading exercises, AR Comp did well in terms of accuracy, but fell short in velocity at reasonable charge levels. CFE 223 did very well in mid to heavier bullet ranges. Norma did better in delivering velocity than it typically does with other cartridges. Both TAC and H335 were standouts.

The little 35 grain bullets require careful handling to start into case mouths while avoiding tipped axis starts and accordion like case necks. Could be a personal problem, but…

With the exception of the way over COL spec 75 and 80 grain loads, all fed reliably from the rifle’s magazine and cycled the action reliably.


The M&P 15T M-LOK is a compact and relatively lightweight, well made AR. You buy it, use it heavily and know that it will be there when needed for a wide… wide variety of applications. As indicated earlier, the M&P 15T M-LOK is complete as shipped. Just add ammo and you are ready to go. When I am done here I am moving on to live fire using the rifle as received, sights and all, and see how I can perform with the M&P and pop up sights for a follow up piece.

It is quite typical for AR 15 reviews to beg he question, how could one manufacturer possibly differentiate themselves from the myriad of other manufacturers. The answer usually focuses on how many inane proprietary features are included that make the customer solely dependent on the manufacturer for parts, service and/or repair. Other times the spotlight shines on included accessories; rail Swiss Army knife, compact camp stove…. the usual.

I think Smith and Wesson differentiates by manufacturing a standard product with contemporary features, the use of quality materials, the use of quality sources where necessary and committing to the customer with the Smith & Wesson life time warranty. Very nice product.