Guns A Guide to Quick-Detach Scope Mounts Steven Kuo June 17, 2018 Join the Conversation From the archives: RECOIL Magazine Issue 17, March/April 2015 MOUNT ‘EM UP One of the most significant trends in recent years has been the widespread adoption of optics to increase shooters' effectiveness with their rifles. And optics manufacturers have risen to the challenge, delivering technological masterpieces — from affordable yet reliable basic models, to indestructible red-dots with nearly infinite battery life, to jack-of-all-trades variable power scopes bristling with features. Yet one constant remains — you must attach that awesome piece of glass to your rifle. It must cling to your boomstick securely and precisely, and if you wish to remove and reinstall your optic at will, it must be utterly consistent as well. In particular, quick-detach scope mounts are designed to provide the flexibility to easily attach and detach an optic from your weapon without any tools and retain your zero. Some of those who are fanatical about their zeroes break into hives at the idea of removing an optic (some of us on staff here included), no matter the type of mount. But there are numerous reasons that this might be useful, including mundane tasks like cleaning and maintenance, or the pursuit of versatility in utilizing multiple optics on the same upper, whether multiple-day optics or to swap in thermals or night vision. Although great strides have been made in terms of durability, glass is still, well, glass. Some of the guys we know who use precision rigs for a living will remove their optic from the weapon when jumping or in other scenarios where sights will be subjected to high G forces. In the (hopefully rare) situation of needing to quickly remove a dead or damaged optic in the field, a QD mount saves time and the need for tools. And even the not-always-justifiable-to-your-wife argument of accepting the price premium for the additional capability, “just in case.” There has been a scope-mount renaissance of sorts in recent years, with more great models available from more companies than ever. They span the gamut from super affordable to beautifully machined pieces of mechanical, deadly art. Generally, they fall into the following two categories: Traditional scope mounts: These utilize the ubiquitous circular scope rings to clamp on the tube of a traditional scope. Typical scope tubes are 1 inch or 30mm in diameter, with heftier optics puffing out to 34mm and even beyond. Most of the mounts of this variety shown here are one-piece affairs, with both front and rear rings affixed to the base. This provides you with convenience as well as confidence that the rings are properly aligned relative to each other. Still, separate front and rear rings have also served shooters well over the years, especially for weapon systems lacking a top rail; however, they're much less commonly found with quick-detach capability (LaRue's two-piece QD offering is included in these pages). These types of mounts accommodate a wide range of scopes and offer nearly infinite adjustment fore and aft (within the constraints of the fixed position of the rings) to precisely dial in your desired eye relief. On the other hand, perfectly leveling your optic can be a bit of chore. Dedicated mounts: With the extremely tight tolerances now permeating the industry (optics and their mounting surfaces, the top rails on rifles, and the finely machined mounts themselves) dedicated scope mounts offer some nice advantages at the expense of being purpose-built. By just tightening a few screws, you can easily attach optics like the Aimpoint Micro Series, Trijicon RMR, or ACOG to their mounts and be assured they're exactly leveled and aligned. No need for plumb lines, bubble levels, or feeler gauges; just plug-and-play. The ACOG dedicated mount interface, for instance, has been adopted for use with other optics as well, such as Trijicon's own VCOG and the thermal scopes we covered in Issue 14. The same applies for other mounting patterns. So put the kids to bed, hide your credit card, and take a gander at some carefully machined badassery. Please note that products from a particular manufacturer naturally all utilize the same type of quick detach mounting system, so the first mention of each company in the traditional scope mounts section addresses those particulars. RETURN TO ZERO One of the key features advertised by scope-mount manufacturers is the ability to remove and reattach your optic without losing your zero. We decided to put this to the test. Gorilla Ammunition provided us with their excellent 69-grain .223 Sierra MatchKing loads, lovingly stuffed into shiny new brass with match-grade primers. (The company also produces 55-grain Sierra BlitzKing and 77-grain Sierra MatchKing rounds). Our test upper was built by Lew Graves at Strong Side Tactical (SST). The heart of any upper is its barrel, and this one featured SST's STRETCH 16 barrel, a cerakoted 16-inch stainless-steel precision barrel turned from a premium McGowen blank, with a .223 Wylde chamber and 1:8 twist. The most unique attribute of the STRETCH 16 barrel is its intermediate-length gas system, placing the gas port between mid-length and rifle length systems; similar to that found on Knights Armament's SR-15, it's been rare to find on a match barrel. The combination with the Gorilla 69-grain SMKs resulted in groups that were consistently sub-MOA, true to SST's accuracy guarantee. In fact, we had numerous groups during our testing hovering around 0.5 MOA, with our best hitting the mark exactly on the dot. Damn impressive performance. (FYI, the average muzzle velocity was 2,743 fps.) A Brownells Magna-Tip adjustable torque handle ensured we tightened all screws exactly to spec, and the Sinclair benchrest and Protektor bags kept us firmly on target. The SST upper also featured a Lantac DGN556B Dragon muzzle brake, SLR Rifleworks Sentry 7 adjustable gas block and Solo Ultra Lite KeyMod handguard, VLTOR MUR-1S receiver, and lightweight polished JP Enterprises LMOS bolt carrier group. Paired with a lightened buffer in our lower, we dialed in the gas block on the intermediate-length system and enjoyed an amazingly soft shooting gun, even softer than an 18-inch rifle-length three-gun competition upper we also brought with us. Why do we tell you all this? Because if you want to reproduce our results and check our work, you have all the info you need to set up something comparable in terms of performance. From the benchrest, we shot multiple groups with a Vortex Razor HD Gen II 1-6×24 scope in each mount, removing and reinstalling it between each string. We scanned the targets and loaded them on the computer to calculate and compare the center points of each group. Overall, the return to zero performance of all the mounts was stellar, with an average zero shift across all the manufacturers of just 0.07 MOA. Most of the mounts had average shifts in the hundredths of MOA in our testing, with the Bobro turning in the smallest at 0.016 MOA and the Burris the largest at 0.22 MOA. We would hardly call our exercise unassailably scientific and hesitate to rank the mounts purely on these test results, so the overall takeaway from our testing is that the scope mounts all performed extremely well on return to zero. Zero Shift (MOA) ADM 0.135 Alamo 0.027 Bobro 0.016 Burris 0.223 GDI 0.045 GG&G 0.043 LaRue 0.076 PRI 0.049 We also used Brownells' sleeved scope alignment rods to check the one-piece scope mounts. All of the mounts were more or less aligned within a hair, testing the tolerances of the alignment tool. TRADITIONAL SCOPE MOUNTS These scope mounts accommodate traditional riflescopes with a main tube, most often 1 inch or 30mm in diameter. All mounts shown here have 30mm rings. American Defense MFG AD-RECON-X-TAC-R Centerline height: 1.47 inches Weight: 8.2 ounces Ring screws: 9/64-inch hex MSRP: $200 Notes: Eat your heart out, Burger King, you can definitely have it your way with ADM's mounts — and at affordable prices to boot. ADM offers a dizzying array of options, including varying amounts of eye relief (extended version shown here), black or dark earth color, numerous ring sizes (1 inch, 30mm, 32mm, 34mm, 35mm, and 40mm), various centerline heights, and standard or larger tactical levers (as shown). Unlike most other mounts in this guide (except for LaRue), ADM's skeletonized scope rings are split vertically, making installation easier since you needn't worry about maintaining even spacing as with horizontally split rings. There are two cross bolts for recoil lugs and two locking levers that clamp down on spring-loaded side bars. They adjust for tension via adjustment nuts opposite the levers. Comes with a wrench and threadlocker. Alamo Four Star DLOC-M4X-30mm Centerline height: 1.5 inches Weight: 7.2 ounces Ring screws: T-25 torx MSRP: $279 Notes: The DLOC is deadly serious about grabbing ahold of your rifle, with six cross bolts for recoil lugs and two spring-loaded clamping side bars, one for each mounting nut. To attach the mount, simply unscrew the nuts, which will provide space to push the clamping bars outward. They are under spring tension, so once you place it on your top rail and let go, the mount will cling to it like your 6 year old on her first day of school. Then tighten the nuts by hand until you can't stand the sharp edges anymore and you're good to go — easy as pie and no tools required. If desired, you can grab a wrench and tighten them to spec for a non-QD installation. The DLOC is finely machined, and the rings held our scope snugly even before we tightened them down. Versions with 34mm rings and more extended eye relief are also available. Bobro Engineering B03-200-300-R9 Centerline height: 1.5 inches Weight: 7.7 ounces Ring screws: T-30 torx MSRP: $236 Notes: The nicely machined Bobro mounts feature a clever design that exerts compressible and constant clamping forces in all directions on the pic rail, thus obviating the need for manual tension adjustments and automatically compensating for any dimensional variations in the rail. If that's too much geek talk, the bottom line is that there's a single QD lever with an automatic spring-loaded lock — just open or close it; there's nothing else to fiddle with. A wrench and Loctite are included. Many versions are available, including single and dual lever models, various ring sizes (1 inch, 30mm, 34mm, 35mm), 20MOA or 30MOA cant, and standard (shown) and extended eye relief. Bobro Engineering Mounts $267.99 brownells.com Burris AR-P.E.P.R. QD mount Centerline height: 1.64 inches Weight: 10 ounces (10.4 ounces with top pic rails) Ring screws: T-15 torx MSRP: $170 Notes: This value priced contender from Burris offers a lot of bang for the buck. While it doesn't match the fit and finish of the other products, it gets the job done and comes with replacement top ring halves with pic rails for attaching accessories. It's extended a moderate amount to provide additional eye relief. The mount has a single recoil lug, two cross bolts, and two locking levers that clamp down on a side bar. The levers can be adjusted by hand. There are six screws per ring, so reach for your electric screwdriver. It's available with 1 inch and 30mm rings; note that the PEPR is made in China. Burris AR-P.E.P.R. QD Mount $107.21 amazon.com Global Defense Initiatives P-ROM L-Model Centerline height: 1.5 inches Weight: 10.8 ounces Ring screws: T-10 torx MSRP: $565 Notes: The heftiest and beefiest mount of the bunch, everything about the GDI screams “over built,” in a good way — except for the attendant premium price. The P-ROM features a single recoil lug, two cross bolts, and two locking levers that secure the clamp bar on the side. The levers are tightened by adjusting the screw opposite the levers. The mount comes with a torx wrench, extra screw, Loctite, and a wonderful custom carrying case (which ironically probably will not get used once you've mounted your optic). The top ring halves are threaded to accept GDI's Modular Adapter Plate System accessories, such as the Trijicon RMR mount pictured here ($185). Variants with 25MOA cants and with 30mm, 34mm, and 35mm rings are available. GG&G FLT Accucam QD Centerline height: 1.46 inches Weight: 6.7 ounces Ring screws: 7/64-inch hex MSRP: $190 Notes: The skeletonized GG&G is quite svelte and lightweight. The long QD lever, while perhaps a bit ungainly in appearance, provides much more leverage than the smaller levers on other mounts and a nice spot for your booger hook (though larger and stubbier fingers will be cramped). There are two cross bolts for recoil lugs, while the lever cinches down the dovetail clamping side bar. Several allen wrenches are provided to secure the 30mm rings and adjust the Accucam lever to the proper tension. GG&G offers standard and slightly extended (shown) eye relief versions, 1-inch delrin ring reducers, a shorter model, and even one specifically designed for the M1A SOCOM II with a reverse cantilever. GG&G FLT Accucam QD $196.99 brownells.com LaRue Tactical LT139-30 SPR/M4 EER Mount QD Centerline height: 1.5 inches Weight: 7.3 ounces Ring screws: T-15 torx MSRP: $232 Notes: An elder statesman in the scope mount business, LaRue and its LT139 have become staples in the market. The scope rings are split vertically, making installation easier since you needn't worry about maintaining even spacing as with horizontally split rings. The mount has two recoil lugs and two levers (one locking) that cam down on the top rail. The LT139 cantilevers forward quite a bit to accommodate optics with a lot of eye relief, such as the increasingly popular low power variable scopes. LaRue offers numerous variations on the theme, including less or no extension, shorter and taller versions, 10 and 20MOA canted models, and 1 inch, 30mm, 34mm, and 35mm rings. It ships with a hex wrench to adjust tightness of the QD levers, torx wrench, extra screw, and Loctite. LaRue Tactical LT808-30 Centerline height: 1.375 inches Weight: 2.8 ounces (each) Ring screws: T-15 torx MSRP: $189 (for pair) Notes: LaRue's two piece scope ring set comes in various heights to clear your optic and optimize your cheek-weld for your particular weapon system, as well as 30mm and 34mm ring sizes. An adjustment wrench, extra screw, and Loctite are included. Precision Reflex Inc AR15/M16 Gator Grip Platform with 30mm High rings Centerline height: 1.63 inches Weight: 9.9 ounces Ring screws: T-20 torx MSRP: $192 Notes: PRI's Gator Grip platform is a unique configurable system with a mounting platform to which you can attach scope rings at various different positions to accommodate your particular optic. 30mm, 1 inch, high, and low rings are available. The QD mount is spring loaded with two recoil lugs and two side clamps. Watch your fingers when working the lever; it's got quite a kick to it. We know this from experience… DEDICATED MOUNTS Aimpoint Micro These mounts are designed specifically for the Aimpoint Micro mounting platform. Note that some other red-dot sights have adopted the same pattern and can be used with these mounts. Red-dot sight mounts for the AR platform are typically offered in various heights, designed to place the red-dot at a certain position relative to the rifle's iron sights when you assume a proper cheek-weld for the optic. An “absolute co-witness” mount will exactly align the dot with the iron sights, so you'll see them on top of each other (if they're not folded down) but maintain the same cheek weld either way. A “lower 1/3 co-witness” places the dot higher than the iron sights, so you get a less obstructed view of the dot, while the iron sights are still available in the lower part of the optic's window — at the lower 1/3 point, hence the moniker. However, this means you'll have a different cheek-weld when employing the red-dot versus iron sights (or traditional rifle scopes). Several mounts are built to place the red dot in between these two positions, to split the difference (they're actually closer to absolute than lower 1/3 co-witness). This tends to be a highly personal preference, so we recommend that you try the different heights to see which you prefer. American Defense MFG AD-T1-11 Weight: 2.9 ounces MSRP: $92 Notes: As you might expect, ADM offers numerous types of Micro mounts, including the one-piece version shown that places the optic for a lower 1/3 co-witness with the front sight. Other models are available in black or FDE, at various heights, with regular or tactical levers, and even a two-piece mount with a modular base that accepts different riser inserts for more versatility. American Defense MFG AD-T1-11 $87.99 amazon.com Alamo Four Star DLOC-MICRO T1 Weight: 1.9 ounces MSRP: $119 Notes: The lightest Micro mount here, the Alamo Four Star places the red-dot just above the front sight post, a tad higher than absolute co-witness. It's a one-piece mount. Bobro Engineering B13-111-002 Weight: 3.6 ounces MSRP: $140 Notes: The absolute co-witness model is shown here, also available in low (for AK, shotgun, etc.) and lower 1/3 co-witness versions. This is a modular two-piece system, and you can swap out the risers. The rear of the riser section is serrated to reduce glare. Bobro Aimpoint Mount $129.99 brownells.com Global Defense Initiatives MT6-OSM Weight: 3.8 ounces MSRP: $210 Notes: The GDI mount is available in four different heights, for lower 1/3 co-witness (shown here), absolute co-witness, low, and for gas-piston or other AR uppers which are a bit taller. Its one piece construction features a cut out on the riser to obstruct less of the shooter's view. GG&G Accucam QD Aimpoint T-1 Mount Weight: 5.1 ounces (5.4 ounces with lens covers) MSRP: $195 Notes: GG&G is known for its integrated lens cover systems for EOTech optics. Its integral lens covers for the T-1 and H-1 stands out amongst the crowd, providing additional protection at the expense of increased bulk and weight. The one-piece mount places the red-dot just above the front sight post, a tad higher than absolute co-witness and not as high as typical lower 1/3 height. Note that this mount does not have a recoil lug on the mounting surface with the Micro. LaRue Tactical LT660 Weight: 2.6 ounces MSRP: $107 Notes: LaRue's popular, one-piece Micro mounts are available in four different heights — for lower 1/3 co-witness (shown here), absolute co-witness, low, and for gas-piston or other taller uppers. The absolute co-witness model (LT751) has a trimmed down I-beam style riser. LaRue Aimpoint Mount $144.00 brownells.com Trijicon ACOG American Defense MFG B3-HD Weight: 4 ounces MSRP: $60 Notes: ADM again offers several varieties of ACOG and modular bases in different lengths and with different risers. They can be had with regular or tactical levers and in black or flat dark earth. Alamo Four Star DLOC-T Weight: 2.8 ounces MSRP: $119 Notes: Alamo's ACOG mount is the lightest of the bunch. Global Defense Initiatives R-COM E-Model Weight: 4 ounces MSRP: $210 Notes: The GDI units have four mounting holes for additional flexibility. GDI also makes a variant with a rear cantilever section to better accommodate shooters with optics that have shallow eye relief. GG&G GGG-1192 Accucam QD Acog Mount Weight: 4 ounces MSRP: $140 Notes: True to GG&G form, they also offer another version of their QD ACOG mount ($192) with integral lens covers to protect your optic (TA01, TA31, TA31F, TA31RCO, and TA01NSN). GG&G ACOG Mount $169.99 brownells.com LaRue Tactical LT100 Weight: 3.3 ounces MSRP: $135 Notes: In addition to the standard LT100 model, LaRue also makes a version for compact ACOGs and one offset further rearward to position the optic farther back. Other American Defense MFG AD-RMR-SOCOM Weight: 3.7 ounces MSRP: $78 Notes: At the risk of sounding like a broken record, ADM again makes a wide variety of one-piece mounts for mini red dot sights, such as the lower 1/3 co-witness model for the Trijicon RMR shown here. Also available are mounts in other heights and colors for sights such as the Burris FastFire, C-More, Insight MRDS, and Vortex Razor. American Defense MFG AD-68-H Centerline height: 1.69 inches Weight: 3.8 ounces MSRP: $110 Notes: The excellent Aimpoint ACO and PRO red dot sights along with various other small 30mm optics need some love too. This is an example of ADM's high-profile Aimpoint mount for a lower 1/3 co-witness. They're also available in other heights and with a forward cantilever. Naturally, other colors and tactical levers are offered as well. Global Defense Initiatives CMC5-OSM Centerline height: 1.5 inches Weight: 5.1 ounces MSRP: $275 Notes: GDI's Aimpoint mounts are available in several heights. The one shown here is the standard version with absolute co-witness and a slight forward cantilever. Global Defense Initiatives MR5-OSM Weight: 3.9 ounces MSRP: $210 Notes: GDI's Trijicon RMR mount features one-piece construction and is offered in several heights for a lower 1/3 co-witness or absolute co-witness, for gas-piston uppers, and for low mount applications like shotguns and AKs. SOURCES American Defense MFG: www.americandefensemanufacturing.com Alamo Four Star: www.alamofourstar.com Bobro Engineering: www.bobroengineering.com BCM: www.bravocompanymfg.com Brownells: www.brownells.com Burris: www.burrisoptics.com Global Defense Initiatives: www.gdiengineering.com GG&G: www.gggaz.com Gorilla Ammunition: www.gorillaammo.com JP Enterprises: www.jprifles.com Lantac USA: www.lantac-usa.com LaRue Tactical: www.laruetactical.com Precision Reflex Inc: www.precisionreflex.com Sinclair International: www.sinclairintl.com SLR Rifleworks: www.slrrifleworks.com Strong Side Tactical: www.strongsidetactical.com VLTOR Weapon Systems: www.vltor.com Vortex Optics: www.vortexoptics.com Explore RECOILweb:Friday Night Gun Porn: Bertram Custom JewelersRECOILtv All Access: Ascendance International's 7.62 Breaching RoundsF.A.B. 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