Other features of the S&W M&P 15 include an alloy receiver, a twenty inch stainless steel match-grade barrel, which, in another example of a nice touch, is clearly marked not only with the chambering, but with the rate of twist, which is one-in-eight-inches. The fore-end used – a Full Float Yankee Hill – allows the barrel to be completely free-floating. An integral Picatanny rail adorns the top of the upper unit and has thirteen slots for mounting an optical device with any Weaver-type rings. (If you choose to mount open sights, in front of the hand guard is a second mini rail with four mounting positions.) This allows considerable latitude in scope location. The buttstock is an A-2 type and the rifle is available in traditional black or Advantage Max-1 camo.
Close-up of left side of M&P 15 PC.
For testing, I mounted two totally different types of optic devices. For the familiarization session and later "plinking", I mounted a Trijicon ACOG, complete with Anti-Reflective Device manufactured by Tenebraex Corp. This, of course, is a very familiar sight to members of the military (and has, in fact, just been adopted by the United States Army) but has only recently been made available for civilian use. Possessing 4x magnification, the fiber optic-lighted reticle is an inverted "illuminated" triangle accompanied by horizontal hash marks below the main reticle. These are calibrated for the 5.6 x 45 round and provide aiming points out to eight hundred meters. When there is not even a hint of ambient light, the reticle is illuminated by a small amount of tritium. I believe the center aiming point is available in either red or yellow, like other Trijicon products – a very appreciated gesture by the considerable number of folks (like myself) who are partly red/green color-blind. In a very classy touch, the ACOG came packed in a hard Pelican case. I have used Trijicon’s more conventional rifle scopes in the past and truly like them. Their Bindon Aiming Concept reticle, especially in their compact 1.25-4x 24 scope, is the quickest reticle I have ever used to get on target, particularly at a moving animal. The scope I mounted for accuracy testing this rifle was a Bushnell 4200 4-16x 50 and which performed perfectly.
I had a fairly extensive choice of factory ammunition to test in this gun. Black Hills, Hornady, Lapua, Norma and Nosler had graciously sent me several weights and types of bullets for testing. All told, I had fourteen different types of factory ammunition. Rumor has it that Winchester, Remington and Federal also make .223 ammunition, but since they wouldn’t even respond to my requests, I cannot report on the quality of any such.
My initial range session consisted of twenty "familiarization" shots following a thorough bore cleaning. After these twenty rounds, I again cleaned the bore and found very little fouling to be present – a tribute to the Black Hills ammunition used for those first twenty shots, as well as the very smooth Smith & Wesson Match barrel. Then I sat down and fired 140 rounds over the chronograph screens (two five-shot groups with each of the fourteen different types of factory ammunition) without any further cleaning until I was finished. There was nary a bobble for the whole session; function was one hundred percent. Accuracy ranged from "OK" to very good, with particularly good groups from the Lapua 69 grain Match, the Hornady 60 grain TAP and the 77 grain Black Hills load. Quite a few groups placed four shots in a very tight cluster with often the first shot out – a quirk often experienced with semi-automatic handguns. This continued to be observed with my hand loads, so was not in any way attributed to any peculiarity of any given factory load. Smith & Wesson claims the PC version will achieve one inch accuracy at 100 yards and my rifle easily did that, and quite often exceeded that goal.
I also observed that while function was literally one hundred percent, this perfection was often obtained over a wide range of velocities, even with any one bullet weight. I’m tempted to say even with different loadings of a single bullet, since various ammunition manufacturers often use the same bullets in their loadings. For instance, Black Hills, Lapua and Nosler all appear to load the 69 grain Sierra MatchKing.
Trijicon 4x ACOG with Anti-Reflective Device attached. A very quick and efficient sighting tool.
No clear preference for any particular weight of projectile could be discerned from these tests, although it did appear that the gun did not particularly care for the one 40 grain load tried. Therefore, when I started testing hand loads, I began with 52 grain bullets on the light side. The heavier extreme was represented by a couple of 75 grain projectiles, since anything heavier than this has to be seated so deeply into the case that the cartridge neck is futilly trying to grasp the ogive of the bullet.
Loading for a gas gun was a new experience for me. I have been around long enough and have read enough articles and reloading manuals to know there are several reloading facets peculiar to these rifles above and beyond the normal considerations, but until this rifle arrived, I never had to implement this theoretical knowledge. For instance, all sources caution that all cases must be completely full-length resized before loading. Believe it! Even 95% resized is not sufficient. On the other hand, most sources state that it may be necessary to use a special small-base resizing die. I did not find this necessary with the S&W M&P 15. In fact, the chamber in this gun was so precise that cases fired six times in the rifle will chamber in my Savage .223-chambered rifle without resizing! Now that is a good chamber! Accordingly, my 1980-dated RCBS standard reloading dies work just fine.