Windham Weaponry’s Big Boy .308 AR—Full Review

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The Windham Weaponry R20FFTM-308 is an AR-10 type design with a fixed, rifle -length stock.

The Windham Weaponry R20FFTM-308 is a 7.62 AR-type rifle with a fixed, rifle-length stock. It delivers amazing power at an affordable price.

For more information, visit https://www.windhamweaponry.com/pdf/NewTechSeets/R20FFTM-308-3-15-16-MSRP.pdf.

To purchase a Windham Weaponry .308 AR on GunsAmerica.com, click this link: https://www.gunsamerica.com/Search.aspx?T=windham%20308.

While media fairies prone to hysterical reactions tend to place the AR-15 in the same death and destruction category as plutonium bombs, Zika Virus, and John Travolta’s singing in the movie Grease, it’s really just the little brother of another popular rifle design—the .308 AR.

How much littler? Ballistically speaking, you can compare the two as follows. The AR in .308 fires the .308 Winchester cartridge while the AR-15 fires the .223 Remington (or 5.56 mm NATO) round. To provide an approximate comparison between the two, we need to look no further than my friend Andrew Chamberlain’s world famous Cartridge Comparison Guide. If we look at kinetic energy, which can be loosely defined as the destructive power of a given cartridge, we find the .223 Remington delivers somewhere in the neighborhood of 1,280 foot-pounds of energy.  That’s for an “average” 55-grain load moving at 3,240 feet per second. An “average” 150-grain .308 Winchester bullet, with a velocity of 2,850 fps, delivers 2,704 foot-pounds of energy at the muzzle – over twice as much!

This rifle is an optics ready flat top configuration.

This rifle is an optics-ready flat top configuration. Note the flat-top upper receiver and the railed gas block forward of the handguard.

SPECS

  • Chambering: .308 Win.
  • Barrel: 20 inches
  • OA Length: 40.75 inches
  • Weight: 9.05 pounds
  • Stock: Magpul MOE fixed
  • Sights: None
  • Action: Direct gas impingement
  • Finish: Matte black
  • Capacity: Detachable box magazine
  • MSRP: $1,667.50

So with that in mind, we’re looking at the Windham Weaponry R20FFTM-308. While there is no reliable industry standard for .308 AR designs as with the AR-15, that’s the pattern that this rifle follows. Just be aware that there is not necessarily complete parts interchangeability between .308 AR “type” rifles from different manufacturers. Also keep in mind that, due to the much larger cartridge size, key components like the lower receiver, bolt and carrier group, and magazines are all different than their AR-15 smaller siblings.

Just for scale, the Windham Weaponry rifle is shown here (top) with the Armalite M-15 we recently reviewed.

Just for scale, the Windham Weaponry rifle is shown here (top) with an Armalite M-15 in 5.56mm.

Windham Weaponry is a relatively new company – sort of. Founded by many of the folks behind the original Bushmaster company, Windham regenerated in 2011 after Remington moved the Bushmaster operation to New York. When his non-compete agreement with Remington ran out from the 2006 purchase by Remington, Bushmaster founder Richard Dyke gauged interest among former employees in the Windham, Maine area about the idea of rebuilding a new company. Interest was high, and the company was again producing rifles within months. The bottom line is that the Windham folks have been building rifles for a long time, just under a different name.

The Tour

The R20FFTM is a fixed-stock configuration rifle. Designed for optics, it arrives without iron sights, and that’s just fine with me. They’d only end up getting in the way of my scope mount anyway. If you want to configure primary or backup iron sights, the front Mil-std 1913 gas block rail is the same height as the receiver rail segment, so alignment is easy.

The fixed buttstock is a Magpul MOE rifle-length.

The fixed buttstock is a Magpul MOE rifle-length unit.

There's a rubber pad on the back of the buttstock. if you want to increase length of pull, you can order a thicker one from Magpul.

There’s a rubber pad on the back of the buttstock. if you want to increase length of pull, you can order a thicker one from Magpul.

You’ll notice plenty of Magpul furniture on the base rifle – another welcome configuration decision. The buttstock is a Magpul MOE Fixed model, and it has a lot going on. The entire comb of the stock is wide and smoothly sloped offering generous cheek weld area. There’s a molded-in sling loop on the underside, but there are also four sockets – two on either side at the receiver and butt end where you can add push-button QD attachment points. The butt pad is rubber and covers a hinged door, so there’s room in the stock to store important things like spare parts or bacon jerky for those long days in the field. All in all, it’s a nice stock, and I like the way it feels.

The front handguard is a Magpul MOE M-Lok rifle-length model. It has six M-lok slots along the bottom and three on each side in the ten and two o’clock positions so that you can mount rail segments or any other M-Lock compatible accessories. The handguard mounts using the standard delta ring, so it’s not a free-floated system. The sides are smooth while the bottom has rounded ridges which help you set and maintain hand placement. There’s also a small ridge on the lower front which helps prevent your hand from sliding forward onto the gas block. Just forward of this ridge is a metal sling swivel so you can attach there or to one of the M-Lok points if you like. Sadly, there’s no bayonet lug, so if you buy this rifle, Senator Dianne Feinstein won’t shed quite as many tears, but that’s OK. I think bayonet charges are mostly a thing of the past anyway.

The handguard is also from Magpul and features M-Lock attachment points at the 2, 6, and 10 o'clock positions.

The handguard is also from Magpul and features M-Lok attachment points at the 2, 6, and 10 o’clock positions.

If you need to stash emergency gear like bacon jerky, there's a hollow area in the stock.

If you need to stash emergency gear like bacon jerky, there’s a hollow area in the stock.

The pistol grip is also upgraded, but it’s a Hogue over molded model. In short, you’re not getting the basic AR-15 plastic furniture components that you’ll want to upgrade right off the bat.

The upper and lower receivers are machined from 7075 T6 aircraft aluminum forgings. Just behind the pistol grip, you’ll find more QD sling attachment points on either side. The trigger guard is machined into the lower receiver so you can’t replace that with an oversized model. The interior space is generous, however, and I didn’t have any trouble using gloves.

The barrel is 20 inches long and made from 4150M Chrome Moly Vanadium 11595E steel. It’s got a 1:10-inch right-hand twist rate and uses six lands and grooves. The rifle comes with an A-2 birdcage style flash hider. That’s mounted on a 5/8x24tpi thread pattern, so you can easily install a muzzle device or suppressor of your choice. The bolt is made from Carpenter 158 steel and is massive, at least in comparison to the standard AR-15 bolt. Interestingly, the staked gas key is identical to those on the smaller AR-15.

The gas block is consistent with the flat top design and is the same height as the receiver rail.

The gas block is consistent with the flat top design and is the same height as the receiver rail.

Under the gas block there's a sling swivel.

Under the gas block there’s a sling swivel.

The controls are exactly what you’d expect on an AR-type rifle. The bolt catch and release button rides on the left, magazine release button on the right, and safety is on the left. The safety is marked on the right side too so that you can see the condition from either side. In fact, the controls are AR-15 compatible. The ejection port cover is larger of course to handle the bigger .308 cartridge.

My sample rifle arrived with a 20-round P-Mag although the current web site specs indicate that the rifle ships with a five-round magazine. As one would most likely buy this rifle from a retailer, it’ll be easy enough to see which one will come with your rifle.

The other furniture is Magpul, but the pistol grip is a Hogue over molded model.

The other furniture is Magpul, but the pistol grip is a Hogue over molded model.

The handguard mounts with the standard delta ring, so it's not a free-floated system.

The handguard mounts with the standard delta ring, so it’s not a free-floated system.

Shooting the Windham Weaponry .308

As you’d expect, the R20FFTM-308 is somewhat heavier than a 5.56mm AR-15 rifle owing to the bigger BBs that it fires. The empty weight without the magazine is 9.05 pounds. Remember that doesn’t include the optic, so unless you install something light like a red dot, you’ll be over ten pounds before loading up the magazine. The overall length is 40.75 inches and stays that way due to the fixed stock.

The upper and lower receivers separate just like a standard AR-15, they're just bigger.

The upper and lower receivers separate just like a standard AR-15, they’re just bigger where needed.

Also somewhat larger is the bolt, shown here next to a large ammo can for scale.

Also somewhat larger is the bolt, shown here next to a large ammo can for scale.

I did most of my testing with a Hawke Optics Sidewinder Tactical scope with a 10x fixed magnification and mil-dot reticle. It weighs about a pound and a half, not counting the Leupold one-piece offset mounting system. Yes, you can use this scope as an impact weapon if all else fails, but that’s another story. For the ranges appropriate for .308 Winchester, the 10x fixed optic was a great pairing, and certainly a configuration I might keep on this setup.

The trigger and hammer components are all standard AR-15 parts, so you can swap out with custom components if you like. The factory trigger is all mil-spec. It’s got a very short takeup followed by a crisp break as far as standard AR triggers go. I measured the pull weight from the center of the trigger, and it averaged about 6¾ pounds.

As we all know, recoil never really disappears, it just gets redirected and hidden depending on the situation. With an AR direct gas impingement design like on the R20FFTM-308, much of the recoil energy is either siphoned off or spread out over time, making the impulse felt by the shooter greatly reduced when compared to a fixed-action rifle of the same caliber. If you shoot a bolt-action .308 next to this one, the Windham feels very tame in comparison. You can shoot this rifle a lot with no discomfort.

I've not yet needed it, but the classic bolt forward assist is there.

I’ve not yet needed it, but the classic bolt forward assist is there.

All the controls are right where you would expect, and for the most part, interchangeable with standard AR-15 parts.

All the controls are right where you would expect, and for the most part, interchangeable with standard AR-15 parts.

I tested a variety of factory and handloaded ammunition in this rifle for function, velocity, and accuracy. To test velocity, I set up a Shooting Chrony Beta Master Chronograph 15 feet in front of the muzzle and fired ten-shot strings to get an average. For accuracy testing, I fired multiple five-shot groups of each ammunition type at 100 yards and averaged the group sizes. Here’s a summary of the accuracy and velocity results.

AmmunitionGroup SizeVelocity
Federal Premium Gold Medal Match .308 Winchester 175 grain1.81”2,567.3 fps
Federal Law Enforcement Bonded SP .308 Winchester 165 grain3.19”2,597.7 fps
Sig Sauer Match Grade OTM  168 grain1.58”2,564.0 fps
Handload: MidSouth Match Monster 168-grain, H48951.88”2,543.5 fps

 

I should note that the handloads using the Midsouth Shooters Supply Match Monster bullets were made using mixed, once-fired .308 brass. While I was careful in assembly, I used a powder dispenser to make a large batch and didn’t weigh each charge separately. Even with that “volume production” method, those bullets performed well, especially considering the $.24 price per each.

I loaded up a pile of ammo using Midsouth Shooters Supply Match Monster 168-grain projectiles. As you'll see, it shot pretty well.

I loaded up a pile of ammo using Midsouth Shooters Supply Match Monster 168-grain projectiles. As you’ll see, it shot pretty well.

The receiver also features QD sling attachment points on both sides.

The receiver also features QD sling attachment points on both sides.

I haven’t had any reliability issues with any of the ammo types tested. Before taking the rifle out, I squirted a little Slip 2000 EWL lube on the bolt and carrier. Other than that, I didn’t provide any special care.

The barrel is fluted to save a little weight and shed heat a bit faster.

The barrel is fluted to save a little weight and shed heat a bit faster.

Why a .308 AR?

So why might you want a big boy AR rifle? As mentioned earlier, the .308 packs a much bigger punch than the .223 Remington/5.56mm NATO. While energy and momentum don’t reflect the whole story, you can make a rough assumption that the bigger cartridge offers double the energy and momentum performance. If you’re looking for more oomph for hunting, penetration, and terminal performance, the .308 AR rifle might be for you. The .308 cartridge also offers better performance at distance. While it’s not an ideal “long range” cartridge, it’ll perform just fine at 800 or 1,000 yards with the right ammo. And you can count on this Windham Weaponry rifle to deliver those rounds capably!

For more information, visit https://www.windhamweaponry.com/pdf/NewTechSeets/R20FFTM-308-3-15-16-MSRP.pdf.

To purchase a Windham Weaponry .308 AR on GunsAmerica.com, click this link: https://www.gunsamerica.com/Search.aspx?T=windham%20308.

I've been shooting several types of match, defensive, and hand loaded ammo through the Windham.

I’ve been shooting several types of match, defensive, and hand loaded ammo through the Windham.

I did accuracy testing using a Hawke Optics Sidewinder Tactical 10x scope from 100 yards.

I did accuracy testing using a Hawke Optics Sidewinder Tactical 10x scope from 100 yards.

{ 16 comments… add one }
  • Mike Watkins February 6, 2017, 2:52 pm

    Been a longtime fan of the AR platform and had a DPMS in .308 for a few years. Now I’ve got one I built from components that the manufacturers would not say were going to be compatible. But when buying, I checked my chosen upper–Alexandria PRO-FAB–pinned to the DPMS lower, and it worked; checked Palmetto’s .308 lower with the DPMS upper, and it worked. So married the two new components to build what I really wanted at the moment.

    Point is, as article points out, all .308 AR components are not compatible and you need to be able to check one against another to see what works, if you’re going to roll your own.

    I don’t have a problem with this Windham offering, or its price. And I’m sure, as several others have said, some barrel break-in will improve groups. Although the best groups the tester obtained really were quite adequate.

    But I’ve owned at least 45 AR’s over the years and the only one I didn’t build myself was the very first, a Colt when not much else had come on the market, and the DPMS LR-308. Both good rifles, but I just don’t seem to get attached. Build one, play with it a while, sell it, build another.

    But having said that, got to point out I’ve been married to the same woman for 46 years. Heheh. 😘

    • Larry Kelley Jr. February 6, 2017, 4:17 pm

      Barrel break ins really,I don’t understand why people say that term, no such thing.its not a car like a car motor. Where you have hundreds of moving parts, that has to have spasific oils an fluids. You do have to have a bit of gun grease, but that’s just to help metal to metal andto help prevent rust. The rest is up to the gun company that made that particular rifle or pistol. If you have to have what’s called a breaking period then that company has not made a gun worth buying. And some companies try and use that word breaking period, it’s not true if so you no how many warranties would be voided. To many to count. Because all they would have to say did yo use the break in period. Then you would think and most likely say I did not no there was one , then you woul be screwed. I have called and talked to to a bunch of places and they say that if the verbally say that there is one the ask them is it anywhere in the description of the manufacturer pamphlet. If so you screwed. But I do not find anywhere in any of my AR purchased rifles pamphlet or in any description that there is one

      • Miles Huggins February 15, 2017, 11:01 pm

        Ar15/ar10 barrel breakin procedure is as follows load magazine to capacity perform mag insertion and chambering exercise dump mag as fast as posible all barrel imperfections eliminated next shots after cool down or hot will be what rifle is capable of shooting with particular load point of impact may move with temp but the accuracy should be stable within reasonable temps with medium contour barrel and thicker and they may or maynot shoot any better groups when free floated because the basic handgard gas block design is really good design for accuracy i shoot nra high power at least once a month and you wouldnt believe the groups out of a standard a2 rifle with a decent trigger and iron peep sights 20 strait shots in the ten ring is the norm without windy conditions

    • Miles Huggins February 15, 2017, 10:47 pm

      Psa pa10 has proprietary takedown pins front is longer than dpms and rear is shorter psa pa10 uppers and lowers receivers only work with psa and also dpms bolt hold open is different from dpms but they do both take 308 pmags, sr25/dpms mags

  • davud February 6, 2017, 1:49 pm

    ‘fairies’? really? like these folks? http://www.pinkpistols.org

    which gun allies you gonna slur next? the kikes (jpfo.org) and the spades (www.naaga.co, http://www.facebook.com/AfricanAmericanGunClub/)?

  • KimberproSS February 6, 2017, 9:15 am

    With a cut or button barrel, especially button, that hasn’t been honed, there needs to be some break in time to smooth out the barrel and achieve the best accuracy. I have DPMS LR308 that required about 250 rounds before all the roughness (I could Feel) in the barrel was smooth out, and along with that the MOA came in right at 1, prior was much higher. I have Rock River Predator (.223) that came with a cryogenic relieved barrel that had been honed, out of the box shot 1/2 MOA with no break in time required.

  • J. February 6, 2017, 8:13 am

    I’m not so sure I would get to worked up “group size” from a right out of the box rifle and a few questions come to mind. What kind of support was used and did the writer take the time to break in the barrel per the manufacturers guidelines?
    I can only offer my experience with my DPMS LR .308 and it’s essentially that it’s accuracy improved vastly in concurrence with the number of rounds fired. I’m not a ballistics or harmonics expert but I do know what works.

  • PAT STRAYHORN February 6, 2017, 7:58 am

    $1700 puts this out of range for a lot of us retired cops living on limited incomes. I bought a DPMS LR-308 Oracle for about 1/2 the price of the Windham and have had no issues with accuracy or reliability. Changed the stock to a magpul moe, added a Nikon Buckmaster scope and she is a solid performer.

    • Alan February 6, 2017, 10:34 am

      What?!!?!?
      But the Author claims it “delivers amazing power at an affordable price”!!!!!! (tongue in cheek)
      So add a good set of sights and/or optic and it’s now around 1800.00, give or take.
      Lets see, mine has Nitride coated bolt and bore, as well as a free float handguard, for $400.00 less.
      So it might be “affordable”, but it isn’t a bargain.

  • BOhio February 6, 2017, 6:13 am

    Not favorably impressed with the accuracy. If it’s not MOA (or better), then it’s not in my stable. However, I’ll get a chance to test a WW AR .308 myself, because I have one purchased in 2015 that’s still slumbering in the original box, unfired. Mine features the laminated wood stock, because IMO it’s more comfortable to shoot (plastic transmits shockwaves to face bones in annoying fashion) and it looks better. I had mine equipped from the factory (via special order of sorts through my LGS) with a Geissele trigger, but even the couple times I dry-fired it I though “uh-oh”, this ain’t no Anschutz or other light-weight match trigger. If I had to guess, I remember the Giessele trigger feeling like it may have been 5 lbs. Doh!

    One of the reasons I bought the WW AR .308 was because the bore twist is 1:10″, which enables the use of heavier bullets such as 175 or 190 (handholds) for better long range performance, i.e. past 600y. The 168 MatchKing is gold out to 600y, but farther out it will become problematic, especially past 800y. Readers, if you’re going to shoot 800y + with your .308, don’t waste your time or ammo with 168 grain stuff. And for shooting past 600y, you really need to do your homework. The .308 come-ups are significant at distance, compared to the 6.5 Creedmoor, 7mm variants, etc.

  • Scott February 6, 2017, 5:18 am

    Accuracy appears to be less than steller for the price point. I picked up an Anderson chambered in 308 for under $800 with much better results. Just under 1″ moa with cheap factory ammo and best groups with my handloads at .33″. Maybe I just got lucky with the AM10, but ar 10’s prices are becoming more competitive.

  • Scott February 6, 2017, 5:18 am

    Accuracy appears to be less than steller for the price point. I picked up an Anderson chambered in 308 for under $800 with much better results. Just under 1″ moa with cheap factory ammo and best groups with my handloads at .33″. Maybe I just got lucky with the AM10, but ar 10’s prices are becoming more competitive.

  • Mark N. February 3, 2017, 1:42 am

    That the .308 AR is a thing cannot be disputed; parts are hard to find, and sold out oat a lot of places. However, the one thing that really bothers me about these rifles is the lack of standardization. You are pretty much stuck buying the upper and the lower from the same source to be assured that they fit, since I have read too many comments about uppers that say they will fit a certain pattern, but end up being off on the rear take down pin locations. So buying an upper is always a crap shoot if you want to build your own.

  • Will Drider December 16, 2016, 12:11 am

    I went straight to the accuracy test results and notes, I’m not impressed. Different match ammo and bullet weight and shoots over 1.5 MOA. Problem is what MOA do you get with good but not “match” ammo? You got 3.2 MOA and that is unacceptable for my tastes. Then again, if you find someting cheap, that it groups well: win/win! We know the 7.62X51 (.308) can be a tack driver and not just in bolt guns. After the dust settles and street prices kick in, some will find value here.

  • DRAINO December 15, 2016, 5:41 pm

    Hmm. I expected a little better accuracy and a better trigger for a Windham…….and a $1600+ price tag???? Not impressive………nor realistic for most average Joe’s. Sorry……call it like I see it. Nice looking weapon….just expected more for that price…..and that company.

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