Smith & Wesson M&P 15 PC Review
By Jeff Munnell
©Copyright, Precision Shooting Magazine
This past July, the good folks from Blue Heron Communications invited a few gun writer types to travel to Encampment, Wyoming, to hunt prairie dogs, ground squirrels, rock chucks and coyotes on the Silver Spur Ranch with Spur Outfitters. We would be using a variety of Smith & Wesson firearms from their Performance Center, but chiefly we would be using their M&P 15 in a couple of configurations chambered for the 5.56 x 45, otherwise known as the .223 Remington. Since I have hunted at Silver Spur before and have always enjoyed my stay and since I have long been a big fan of Smith & Wesson products, I thought this would be a rather enjoyable mid-summer interlude. Accordingly, it took me all of 1.7 seconds to accept the invitation.
Author with rock chuck shot in creek bed with S&W M&P 15 PC while hunting with Spur Outfitters in Wyoming. My hunting partner of the day, fellow writer, Dr. George Dvorchak, claimed the rock chuck had to have been retarded to be found so far from its usual haunts. However, I believe that it was really an alien from a distant galaxy and I spared the Earth from conquest by shooting it!
An interesting vacation palling around with a bunch of kindred spirits aside, I had a particular interest in this trip. While we residents of the Keystone State are very fortunate to have quite a supply and variety of game to hunt, as well as some of the best "low mountains" in the U.S. in which to hunt them, semi-automatic rifles and handguns are strictly verboten for any and all hunting uses. This being the case, it is even neigh on to impossible to find any semi-automatic rifles in the racks of the various local gun shops. (Of course, since the election, even our dealers have been ordering – and selling – any AR-platform rifles they can find; such is the power of even not-yet-installed liberal presidents and congresses.) Thus, my experience with the so-called "gas guns" or "black rifles" was negligible before this trip.
Since the young of the coyote are not fully whelped by mid-July in Wyoming, hunting for these rascals was non-existent. Likewise, for whatever reason, rock chucks were rather scarce. For those readers not familiar with this particular varmint sub-species, these appear like red-haired western cousins of the eastern groundhog: same size, same general appearance, etc. Their common name comes from their penchant for inhabiting the higher elevations of the rocky mountain foothills (if 10,000 feet can still be a "foothill") and, in particular, for their propensity to sun themselves by lying on the very tops of totally exposed rocks. Now I don't relate this history simply to show off my taxonomic knowledge, but rather as background for saying that the only rock chuck taken by our particular group of hunters was shot by yrs trooly in a creek bed. Don't ask me what he was doing there, but if by chance he was a member of a rock chuck vanguard looking for a new place to reside, I trust the rest of the clan vetoed this particular idea. None shall escape the ever vigilant eye of guide Roger Cox!
Close-up of right side of the S&W M&P 15 receiver with open dust cover.
In any event, the prairie dogs and ground squirrels were present by the thousands and I became thoroughly impressed with the ability of the S&W M&P 15 PC I was assigned to hit them on a regular basis. (Please note that in this instance "PC" stands for Performance Center; there is not much politically correct about this rifle.) The good folks at Hornady Manufacturing went above and beyond and supplied humungous amounts of their superb 53 grain Match hollow point ammunition, and it proved to be more than accurate enough to regularly hit four to eight inch tall rodents out to two hundred yards or so. Although this is generally as far a shot as is presented in the sage-dotted flatlands of the Wyoming high plains, one particular colony of dogs did present several shots at four hundred nine yards, and on the eighth try I connected with the fattest member of the family. Credit for the hit must be equally split between the S&W rifle, the Hornady ammunition and the excellent Bushnell 6-24x Tactical scope mounted on my particular gun. Kudos to Bushnell for supplying all of us shooters with varieties of the excellent optics.
Since Tony Miele, who heads up the S&W Performance Center was along on the hunt, I requested that he send me one of these rifles for more thorough testing and evaluation whenever he could. In due course, one arrived at Seitzinger's gun shop. (Thank goodness it was before the election and Randy was not tempted to turn a quick buck with my "loaner". Actually, I was not at all concerned – he would merely tell me he had sold it simply to jerk my chain.) As received, the gun came in a semi-hard rigid plastic case which in turn was in a sturdy cardboard sleeve – an excellent and very practical way of shipping any rifle. Nice touch, Tony! With a ten-shot magazine in place but not loaded, the gun weighs seven pounds, nine ounces (the specs call for eight pounds, two ounces) and measured 381/2 inches in length. Trigger pull for the impressively crisp two-stage trigger was an even five pounds. (For those young pups in the audience, yes "crisp" can be a proper descriptive adjective when used with the term "two-stage trigger". When done right, as was the case with this S&W, such a trigger is very predictable and controllable, even when the final release is five pounds.)
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.
Even though we always must be concerned with cartridge over-all length, it is particularly important that cartridges not only fit the magazine of a gas gun, but that a little extra room between bullet tip and magazine well exist, otherwise the cartridges shift in the magazine upon firing and may not feed properly. Again, contrary to most written opinions, this rifle did not seem to care whether any crimp was applied to the bullet or not; neck tension was sufficient with all bullets tried. Many .224" inch bullets, particularly thin-jacketed varmint and match bullets, are not cannelured for crimping anyway, and anything but a very light crimp can adversely affect accuracy.
S&W M&P 15 PC with both optical devices tested by Munnell. Top is Trijicon 4x ACOG with Anti-Reflective Device attached to front; bottom is Bushnell Elite 4200 4-16 x 50 scope.
Perhaps the one peculiarity of gas guns to which we must pay the closest attention is the pressure generated by any given load and the bolt thrust delivered during firing. Not only peak pressure, but also the pressure curve and port pressure must fall within a fairly narrow range. Too little pressure and the bolt will not retract far enough or fast enough to give reliable extraction/ejection of the fired case and/or permit the stripping of the next round from the magazine. Too much bolt velocity will over-stress the action and actually may be so fast as to over-ride the next round. Although various sources list powders from VihtaVuori N-120 on the fast side through IMR 4064 on the slow side as suitable, the powders at both ends of this range can present problems. My tests indicate that the faster powders only present a very small window in which charges will reliably work the action but yet are not so "hot" as to unduly stress the parts. The slowest permissible powders often fill the case too full, especially for the longer bullets, and often leave too much residue, thus creating at least the potential to jam the action. As a general rule of thumb, the faster powders are more suitable only for the lighter bullets.
Please note that velocity alone is not the determiner of the proper functioning of the gun; it is the peak pressure, port pressure and the pressure curve that make the difference between faultless function and feeding jams. For instance, using the 60 grain Hornady V-Max bullet, I achieved 100 percent function with velocities between 2452 fps and 2785 fps, depending upon the powder used, and with the 69 grain Sierra MatchKing, different loads functioned perfectly with velocities between 2503 and 2874 fps.
Powders I found suitable with one bullet or another included IMR 4198, VV N-120, AA 2460, 3031, AA 2015, Bench Mark, WW 748 and H 4895. There are several others, such as AA 2230, H 322 and H 335, that are not only suitable but practically mainstays for at least the 55 grain bullet in the AR-types of guns.
A few powders worked satisfactorily with the lighter bullets tried, but gave erratic or unpredictable results with heavier weights. VV N-120 and IMR 4198 would fall within this classification. In fact, with the 69 grain Sierra, I could not convince any load using IMR 4198 to work the action reliably.
This rifle showed no desire to require any particular primer, therefore for all testing, I relied on the CCI 400 standard force small rifle primer and encountered no problems by doing so.
Smith & Wesson M&P 15 PC with Bushnell Elite 4200 4-16 x 50 scope on author's shooting bench. The combination provided many small groups, both with factory loads and the author's hand loads.
Bullets tried included the 52 grain Berger Match, 55 grain Barnes Multi Purpose Green (a non-lead varmint bullet), the 60 grain Hornady V-Max, 69 grain Sierra MatchKing and 75 grain examples from both Hornady (A-Max) and Berger (Match HP). The latter two are Very Low Drag-type bullets and take about as much powder space as can be afforded. This, plus the fact that even a strong crimp probably would not touch the jacket due to the mouth of the case being well forward of the beginning of each bullet's ogive when seated to clear the magazine, means that any heavier or longer bullets would likely not function correctly.
While I shot some very good groups with all bullets tried, I still experienced several instances with the first shot being out of the group. Although the round fore-end on this rifle and the very high comb (which played havoc with my earmuffs) are not the most conducive to resting on sand bags and bench shooting, still shooting sub-one inch groups was easily accomplished, with the occasional group of around one-half inch showing up on the 100 yard target. The surprising bullet to me, considering that I don't have a lot of experience with it, was the 55 grain Barnes MPG. Even though I only fired five groups with it, utilizing three powders, still four groups were under one inch and the smallest was nine-sixteenth of an inch. This was the largest proportion of small groups fired with any one bullet. The one bullet on which I spent a lot more time and which produced a good proportion of small groups was the 69 grain Sierra MatchKing. There were several instances of one-half to three-fourth inch groups fired with this bullet and most of the larger groups had a single flier. All in all, any of the bullets I tried could be coaxed into at least a few small groups and in almost all instances, these results were repeatable. When they didn't repeat, there was more than a fair chance that the problem was mine – not the gun's.
With the Barnes bullet, the powder to beat seemed to be AA 2015, and with the 69 grain Sierra, it, as well as Hodgdon's Bench Mark, gave very good results. Although good accuracy with this latter bullet was also obtained with IMR 4198, the use of this combination was somewhat touchy and the rifle's action did not always completely function. 22.5 and 23 grains of Bench Mark were the most reliable loads and both gave good accuracy with the Sierra bullet. With the Barnes bullet, the same loads performed wonderfully, as did 21 and 21.5 grains of Accurate 2015. The 52 grain Berger, coupled with 23.5 grains of Bench Mark or 21.5 grains of 2015 was also very impressive and totally reliable.
There is no doubt that AR-platform guns can be used successfully for match shooting. Carl Bernosky, who uses an S&W M&P 15-based rifle, has won the NRA Match High-Power Rifle Championship, the NRA Civilian and the NRA Match Rifle Championships. In doing so, he was often competing against some darn good bolt rifles. My recent experiences with this S&W M&P 15 PC has opened my eyes to a brand new type of rifle. Just what I needed; another "hobby"!
(NOTE: Neither the writer nor the publisher makes any representation of the safety of loads quoted here in other rifles. They were safe, in that gun, on that day. Start ten percent lower with your initial powder charge and work your way up slowly, watching for signs of pressure.)
By Jeff Munnell
©Copyright, Precision Shooting Magazine
This past July, the good folks from Blue Heron Communications invited a few gun writer types to travel to Encampment, Wyoming, to hunt prairie dogs, ground squirrels, rock chucks and coyotes on the Silver Spur Ranch with Spur Outfitters. We would be using a variety of Smith & Wesson firearms from their Performance Center, but chiefly we would be using their M&P 15 in a couple of configurations chambered for the 5.56 x 45, otherwise known as the .223 Remington. Since I have hunted at Silver Spur before and have always enjoyed my stay and since I have long been a big fan of Smith & Wesson products, I thought this would be a rather enjoyable mid-summer interlude. Accordingly, it took me all of 1.7 seconds to accept the invitation.
Author with rock chuck shot in creek bed with S&W M&P 15 PC while hunting with Spur Outfitters in Wyoming. My hunting partner of the day, fellow writer, Dr. George Dvorchak, claimed the rock chuck had to have been retarded to be found so far from its usual haunts. However, I believe that it was really an alien from a distant galaxy and I spared the Earth from conquest by shooting it!
An interesting vacation palling around with a bunch of kindred spirits aside, I had a particular interest in this trip. While we residents of the Keystone State are very fortunate to have quite a supply and variety of game to hunt, as well as some of the best "low mountains" in the U.S. in which to hunt them, semi-automatic rifles and handguns are strictly verboten for any and all hunting uses. This being the case, it is even neigh on to impossible to find any semi-automatic rifles in the racks of the various local gun shops. (Of course, since the election, even our dealers have been ordering – and selling – any AR-platform rifles they can find; such is the power of even not-yet-installed liberal presidents and congresses.) Thus, my experience with the so-called "gas guns" or "black rifles" was negligible before this trip.
Since the young of the coyote are not fully whelped by mid-July in Wyoming, hunting for these rascals was non-existent. Likewise, for whatever reason, rock chucks were rather scarce. For those readers not familiar with this particular varmint sub-species, these appear like red-haired western cousins of the eastern groundhog: same size, same general appearance, etc. Their common name comes from their penchant for inhabiting the higher elevations of the rocky mountain foothills (if 10,000 feet can still be a "foothill") and, in particular, for their propensity to sun themselves by lying on the very tops of totally exposed rocks. Now I don't relate this history simply to show off my taxonomic knowledge, but rather as background for saying that the only rock chuck taken by our particular group of hunters was shot by yrs trooly in a creek bed. Don't ask me what he was doing there, but if by chance he was a member of a rock chuck vanguard looking for a new place to reside, I trust the rest of the clan vetoed this particular idea. None shall escape the ever vigilant eye of guide Roger Cox!
Close-up of right side of the S&W M&P 15 receiver with open dust cover.
In any event, the prairie dogs and ground squirrels were present by the thousands and I became thoroughly impressed with the ability of the S&W M&P 15 PC I was assigned to hit them on a regular basis. (Please note that in this instance "PC" stands for Performance Center; there is not much politically correct about this rifle.) The good folks at Hornady Manufacturing went above and beyond and supplied humungous amounts of their superb 53 grain Match hollow point ammunition, and it proved to be more than accurate enough to regularly hit four to eight inch tall rodents out to two hundred yards or so. Although this is generally as far a shot as is presented in the sage-dotted flatlands of the Wyoming high plains, one particular colony of dogs did present several shots at four hundred nine yards, and on the eighth try I connected with the fattest member of the family. Credit for the hit must be equally split between the S&W rifle, the Hornady ammunition and the excellent Bushnell 6-24x Tactical scope mounted on my particular gun. Kudos to Bushnell for supplying all of us shooters with varieties of the excellent optics.
Since Tony Miele, who heads up the S&W Performance Center was along on the hunt, I requested that he send me one of these rifles for more thorough testing and evaluation whenever he could. In due course, one arrived at Seitzinger's gun shop. (Thank goodness it was before the election and Randy was not tempted to turn a quick buck with my "loaner". Actually, I was not at all concerned – he would merely tell me he had sold it simply to jerk my chain.) As received, the gun came in a semi-hard rigid plastic case which in turn was in a sturdy cardboard sleeve – an excellent and very practical way of shipping any rifle. Nice touch, Tony! With a ten-shot magazine in place but not loaded, the gun weighs seven pounds, nine ounces (the specs call for eight pounds, two ounces) and measured 381/2 inches in length. Trigger pull for the impressively crisp two-stage trigger was an even five pounds. (For those young pups in the audience, yes "crisp" can be a proper descriptive adjective when used with the term "two-stage trigger". When done right, as was the case with this S&W, such a trigger is very predictable and controllable, even when the final release is five pounds.)
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.
Even though we always must be concerned with cartridge over-all length, it is particularly important that cartridges not only fit the magazine of a gas gun, but that a little extra room between bullet tip and magazine well exist, otherwise the cartridges shift in the magazine upon firing and may not feed properly. Again, contrary to most written opinions, this rifle did not seem to care whether any crimp was applied to the bullet or not; neck tension was sufficient with all bullets tried. Many .224" inch bullets, particularly thin-jacketed varmint and match bullets, are not cannelured for crimping anyway, and anything but a very light crimp can adversely affect accuracy.
S&W M&P 15 PC with both optical devices tested by Munnell. Top is Trijicon 4x ACOG with Anti-Reflective Device attached to front; bottom is Bushnell Elite 4200 4-16 x 50 scope.
Perhaps the one peculiarity of gas guns to which we must pay the closest attention is the pressure generated by any given load and the bolt thrust delivered during firing. Not only peak pressure, but also the pressure curve and port pressure must fall within a fairly narrow range. Too little pressure and the bolt will not retract far enough or fast enough to give reliable extraction/ejection of the fired case and/or permit the stripping of the next round from the magazine. Too much bolt velocity will over-stress the action and actually may be so fast as to over-ride the next round. Although various sources list powders from VihtaVuori N-120 on the fast side through IMR 4064 on the slow side as suitable, the powders at both ends of this range can present problems. My tests indicate that the faster powders only present a very small window in which charges will reliably work the action but yet are not so "hot" as to unduly stress the parts. The slowest permissible powders often fill the case too full, especially for the longer bullets, and often leave too much residue, thus creating at least the potential to jam the action. As a general rule of thumb, the faster powders are more suitable only for the lighter bullets.
Please note that velocity alone is not the determiner of the proper functioning of the gun; it is the peak pressure, port pressure and the pressure curve that make the difference between faultless function and feeding jams. For instance, using the 60 grain Hornady V-Max bullet, I achieved 100 percent function with velocities between 2452 fps and 2785 fps, depending upon the powder used, and with the 69 grain Sierra MatchKing, different loads functioned perfectly with velocities between 2503 and 2874 fps.
Powders I found suitable with one bullet or another included IMR 4198, VV N-120, AA 2460, 3031, AA 2015, Bench Mark, WW 748 and H 4895. There are several others, such as AA 2230, H 322 and H 335, that are not only suitable but practically mainstays for at least the 55 grain bullet in the AR-types of guns.
A few powders worked satisfactorily with the lighter bullets tried, but gave erratic or unpredictable results with heavier weights. VV N-120 and IMR 4198 would fall within this classification. In fact, with the 69 grain Sierra, I could not convince any load using IMR 4198 to work the action reliably.
This rifle showed no desire to require any particular primer, therefore for all testing, I relied on the CCI 400 standard force small rifle primer and encountered no problems by doing so.
Smith & Wesson M&P 15 PC with Bushnell Elite 4200 4-16 x 50 scope on author's shooting bench. The combination provided many small groups, both with factory loads and the author's hand loads.
Bullets tried included the 52 grain Berger Match, 55 grain Barnes Multi Purpose Green (a non-lead varmint bullet), the 60 grain Hornady V-Max, 69 grain Sierra MatchKing and 75 grain examples from both Hornady (A-Max) and Berger (Match HP). The latter two are Very Low Drag-type bullets and take about as much powder space as can be afforded. This, plus the fact that even a strong crimp probably would not touch the jacket due to the mouth of the case being well forward of the beginning of each bullet's ogive when seated to clear the magazine, means that any heavier or longer bullets would likely not function correctly.
While I shot some very good groups with all bullets tried, I still experienced several instances with the first shot being out of the group. Although the round fore-end on this rifle and the very high comb (which played havoc with my earmuffs) are not the most conducive to resting on sand bags and bench shooting, still shooting sub-one inch groups was easily accomplished, with the occasional group of around one-half inch showing up on the 100 yard target. The surprising bullet to me, considering that I don't have a lot of experience with it, was the 55 grain Barnes MPG. Even though I only fired five groups with it, utilizing three powders, still four groups were under one inch and the smallest was nine-sixteenth of an inch. This was the largest proportion of small groups fired with any one bullet. The one bullet on which I spent a lot more time and which produced a good proportion of small groups was the 69 grain Sierra MatchKing. There were several instances of one-half to three-fourth inch groups fired with this bullet and most of the larger groups had a single flier. All in all, any of the bullets I tried could be coaxed into at least a few small groups and in almost all instances, these results were repeatable. When they didn't repeat, there was more than a fair chance that the problem was mine – not the gun's.
With the Barnes bullet, the powder to beat seemed to be AA 2015, and with the 69 grain Sierra, it, as well as Hodgdon's Bench Mark, gave very good results. Although good accuracy with this latter bullet was also obtained with IMR 4198, the use of this combination was somewhat touchy and the rifle's action did not always completely function. 22.5 and 23 grains of Bench Mark were the most reliable loads and both gave good accuracy with the Sierra bullet. With the Barnes bullet, the same loads performed wonderfully, as did 21 and 21.5 grains of Accurate 2015. The 52 grain Berger, coupled with 23.5 grains of Bench Mark or 21.5 grains of 2015 was also very impressive and totally reliable.
There is no doubt that AR-platform guns can be used successfully for match shooting. Carl Bernosky, who uses an S&W M&P 15-based rifle, has won the NRA Match High-Power Rifle Championship, the NRA Civilian and the NRA Match Rifle Championships. In doing so, he was often competing against some darn good bolt rifles. My recent experiences with this S&W M&P 15 PC has opened my eyes to a brand new type of rifle. Just what I needed; another "hobby"!
(NOTE: Neither the writer nor the publisher makes any representation of the safety of loads quoted here in other rifles. They were safe, in that gun, on that day. Start ten percent lower with your initial powder charge and work your way up slowly, watching for signs of pressure.)
