16″ 5.56 NATO Quattro-15 Monobloc® A5 Rifle

Description

Their capacity. Our architecture. One rifle. The Quattro-15 lower and the QMAG-53 magazine are developed and manufactured by Desert Tech. The pairing is ours: an HM Defense Monobloc® upper, thermal fitted to a SOTM4 MOD-0 forged receiver, built by the SOT Custom Shop on the Quattro-15 lower, a combination Desert Tech does not offer. Bombproof by Design™.

Open the zoom viewers: both sides of the rifle, photographed as built with the standard A2 Extended Flash Hider: 15″ M-LOK handguard · 13″ M-LOK handguard · 13″ quad rail.

Choose the handguard (15″ or 13″ SOT Wedge-Lock M-LOK, or the 13″ SOT Wedge-Lock Picatinny quad rail) and the barrel bore (chrome-lined or standard) when you order.

Barrel

• 16″ HM Defense Monobloc®, 4150 chrome-moly steel (CrMo), Black Cerakote®: chrome-lined bore ($2,299.00) or standard bore ($2,100.00)
• Balanced barrel taper/profile
• 5.56×45mm NATO, .223 Remington compatible · 1:8 twist · 1/2×28 muzzle thread
• Mid-length gas, with the gas block milled straight into the barrel blank: no separate block to clamp, pin or shift
• A2 Extended Flash Hider, Black Cerakote®, standard
• Optional add-on: 4-port hardened flash hider, Black Cerakote®, $40.00
• Optional add-on: Faxon MuzzLok® Gunner 3-port 5.56 steel muzzle brake, $60.00
• Optional add-on: Faxon MuzzLok® stainless steel Plan B muzzle brake, $75.00
• Other choices on inquiry: we offer a wide variety, including mounts for many suppressor manufacturers and other Plan B options. Contact us
• Suppressor-ready with any of the Faxon MuzzLok® brakes: the MuzzLok® removes to leave the 1/2×28 thread for a direct-mount suppressor

Upper Receiver

• SOTM4 MOD-0 forged upper, 7075-T6, black anodized, barrel thermal fitted with no retaining compound and no bedding
• Forward assist, phosphate finish
• SOT Enhanced HMB™ bolt carrier group, Black Nitride (standard)
• Optional upgrade, in place of the standard group: Young Manufacturing M16 Chrome BCG with HMB™ bolt, $149.00, supplied as Young Manufacturing build it, without SOT’s enhancements: no arrow-indexed cam pin, no index-marked gas key, and the gas key is not staked
• Optional upgrade, in place of the standard group: Microbest Super-Stake C158 all-chrome BCG, heavy-duty stake, with chrome HMB™ bolt, $149.00
• Arrow-indexed cam pin on the standard SOT Enhanced group — always installed in the same direction for better wear and cam pin life
• Index-marked gas key on the standard SOT Enhanced group
• Laser-engraved caliber markings inside and outside the ejection port cover for rapid visual caliber confirmation
• Breek Arms WARHAMMER Mod2 ambidextrous charging handle

Handguard

• 15″ or 13″ SOT Wedge-Lock M-LOK, black anodized, free float, full-length top Picatinny rail
• Or the 13″ SOT Wedge-Lock Picatinny quad rail, black anodized, free float
• Twin-lug wedge lock to a steel barrel nut, with anti-rotation tabs

Lower Receiver

• Desert Tech Quattro-15, machined from a 7075-T6 aluminum forging, black Type III hard-coat anodized (rollmarked MULTI-CAL)
• Integrated trigger guard, forged into the lower
• Radian Talon ambidextrous safety selector, black
• Desert Tech proprietary ambidextrous bolt release and magazine release, standard on every Quattro-15
• Nitride pivot pins (SOT standard)
• Integrated QD sling socket on the left side of the receiver
• Upper receiver tensioning set screw (fit and feel, not accuracy)
• LaRue Tactical MBT-2S two-stage trigger, curved bow (standard) or straight bow: the only trigger offered on the Quattro-15 series
• VLTOR A5 receiver extension, A5H2 buffer and A5 rifle-length spring

Furniture

• B5 Systems Enhanced SOPMOD stock, black
• B5 Systems Type 23 P-Grip, black, with the B5 Systems grip plug

Extra Information

• Overall length 34.5″ with the stock collapsed, 38″ extended, with any of the three handguards · weight unloaded 7 lb 0.9 oz with the 15″ M-LOK, 6 lb 3.6 oz with the 13″ M-LOK, 7 lb 9.9 oz with the 13″ quad rail
• Ships with one Desert Tech QMAG-53 (53-round quad stack)
• Ships in a 42″ black Plano SE rifle case: high-density molded polymer, high-density interlocking foam
• Includes the Desert Tech Quattro-15 Magwell Adapter Kit (P/N ACC0292), which lets the dedicated quad-stack Quattro-15 lower accept standard USGI and traditional AR-15 / STANAG pattern 30-round magazines
• Not available in California, Connecticut, Delaware, Illinois, Maryland, Massachusetts, New Jersey, New York, Rhode Island, Washington or Washington, D.C.
• Colorado and Vermont restrict the 53-round QMAG-53 but not the rifle: there, and wherever magazine-capacity limits apply, the rifle ships with compliant magazines instead, and the adapter is included regardless
• Laws change: please confirm with your local FFL before ordering
• Optional add-on: Magpul MBUS 3 front & rear flip-up sight set (MAG1166-MAG1167), black, $75.00: impact-resistant polymer, spring-loaded with an ambidextrous push-button, tool-less front elevation, rapid-select rear aperture, 0.44″ high folded, standard AR height deployed, Picatinny mount, made in the USA
• Title I rifle · ships to your FFL dealer only

MONOBLOC® and HMB™ are marks of HM Defense, LLC, used under license. Desert Tech, Quattro-15 and QMAG are marks of Desert Tech; VLTOR of VLTOR Weapon Systems; B5 Systems of B5 Systems. Their appearance indicates that Second of Ten incorporates the component, not sponsorship, affiliation or endorsement.