Mk12 Mod 1 Near Clone Premium Upper Receiver Group, Complete

$1,999.00 - $2,564.00
assembled as ordered, generally ships within 3 weeks

Premium Mk12 Mod 1 Near Clone Upper Receiver Group, Complete from Potomac Armory

Featuring an 18" SPR barrel (of your choice), Allen Engineering hardware, sights and mount.

Lone Survivor Gun

Seen here in the film Lone Survivor, the Mk12 sniper rifle started as the SPR project in late 1990's and became the most popular M16/M4 based 5.56 sniper rifle in the global war on terror. The Mod 1 version got started with NSWC in 2001/2002 and spread from the US Navy SEALS to USMC, and has been one of the more fun guns to build, buy, and shoot. The combination of a tuned Mk12 with the right barrel and ammo is a very accurate platform at distances of 600 yards and beyond.

At Charlie's, we work in terms of near clone and clone correct options. Some of our clone correct models have other identifiers. For the near clone market, we take the authentic military correct design and get very close to the real deal, but some parts are generic and sometimes other manufacturer's parts are used. Our near clone offering takes the best aspects of the military correct upper receiver group and finds ways to get past the difficulties of hard to find and/or expensive parts and make a good replica available, in much the same way that PRI has made a near clone Mk12 Mod0 available to the public. Potomac Armory has worked with Charlie's to design and assemble a very good shooting upper, which can be nicely paired with any solid forged military style lower from Colt, FN, LMT, Rock River and others.

This model, the Premium Near Clone, looks very much like the Mk12 Mod1 from a distance, as the LaRue quad rail is used, which has a round end cap connecting the rail to the receiver, in much the same manner as the Knights Armament rifle-length RAS rail used on the Mod 1 SPR rifle. (Some would even consider the LaRue an improvement over the KAC, given its anti-rotation locking plate.)

Mk12 Barrel

The heart of a sniper rifle is the barrel; here, we present the option of either a military clone correct Douglas 18" barrel in 416 stainless steel, button cut, with a 1:7 twist and chambered in CLE (very similar to 5.56 NATO and .223 Wylde) - or - a Criterion barrel with the same specifications. Douglas is the barrel that came with the Mk12, and Criterion is a solid choice of good barrel at a slightly lower price point. Your choice might be a matter of what is in stock at the time you order. 

Mk12 Handguard/Rail

The upper receiver comes with a LaRue Quad Rail Handguard with LaRue Locking System. The LaRue rail is very similar in look and design to the Knights Armament rail, which is the military correct rail originally found on the Mk12 Mod1. The KAC RAS was one of the first free-floating rails, which takes the pressure of the bipod, hand, and accessories off of the barrel, allowing the barrel to freely vibrate. This demonstrably adds to the accuracy of the barrel and the entire weapon system. The LaRue rail adds built-in steel QD disconnects at the rear of both sides of the rail. The 12" length exposes the Mk12 gas block slightly ahead of the rail, in the same manner as the KAC RAS.

The LaRue rail is accented with Knights rail covers, to help give you that Mk12 characteristic look.

Upper Receiver

The upper receiver is a military-grade 7075 T6 forged receiver, of similar quality to many name brand mil spec receivers, but does not have a dry lube interior, for example, like Colt does. The receiver will come from one of several name brand forges and have the marking of a square, keyhole, or broken-A.

Mk12 Gas Block and M84 charging handle

The Potomac Armory Mk12 Mod 1 near clone upper also features the PRI M84 black gas buster charging handle and a NAVSEA Mk12 gas block and military grade stainless gas tube, all of which were standard on military issue Mk12's. The PRI Gas Buster M84 charging handle was ahead of its time, and provided a good barrier between the noxious gasses inside the charging area and the shooter's face. The Mk12 gas block has been used by the Navy SEALS for 20 years and will not come off. Some recent marketing has touted the advantage of a pinned gas block, but with the correct dimpling of the barrel and Loctite application to the set screws, the gas block is not coming off without some serious gunsmith attention. Having a true Mk12 gas block is a sign of having the correct components for the rifle of this period.

Ops Inc. Hardware

As the military correct Mod 1 uppers would have, as well as the Allen Engineering SPR long collar and perfectly timed brake with thread protector. The Allen Engineering hardware is 100% the real deal, as Allen did all the construction of the earlier Ops Inc. suppressors and hardware. The installation of the brake is checked by manually attaching a suppressor to assure the correct number of turns to secure an Ops Inc. style suppressor. This is where the craftsmanship comes in: we take care to ensure the right number of shims and spacers to guarantee the proper alignment of the break ports, while also providing for the correct installation of the suppressor. Every upper is checked for suppressor fit and bore alignment using a Surefire bore guide.

Sights and Scope Rings

Charlie's knows that some of you buy parts and hold them, and others have their own favorite sights or scope mount, so the sights and rings are offered as an option. If selected, the back-up iron sights are the military correct Knights flip-up sights: rear full size 200-600 meter sights and front M4 period correct flip-up sight in black. The rings, if selected, are the ARMS #22 HIGH rings in 30mm, which is perfect for the period correct Leopold or Nightforce scopes, or another 30mm scope of your choosing.

Note: Pictures show the optional back-up iron sights install, which, like the ARMS scope rings, are an option.


  • Milspec forged upper receiver 7075-T6 military grade aluminum with Type 3 hardcoat black anodizing, complete with milspec forward assist and dust cover
  • SPR profiled barrel in 416R stainless with your choice of Douglas or Criterion blanks, handcrafted by Compass Lake Engineering with their CLE chamber, 1:7 twist, 18.1", coated in US Navy spec gray Gunkote
  • Allen Engineering SPR brake and long collar, professionally timed and installed by attaching an AEM5 suppressor for testing and tested with Surefire bore rod for concentricity
  • LaRue 12" Quad Rail Free-Floating Handguard with Picatinny on all four sides
  • Rail is 6061 aluminum and Type 3 hardcoat anodized in black, 2.43" tall with an inner diameter of 1.3" - comes with 4140 heat treated barrel nut with screws and barrel wrench included
  • Precision Reflex, Inc. (PRI) factory M84 Gas Buster charging handle
  • NAVSEA Mk12 gas block, phosphated steel alloy with military grade stainless gas tube, either Colt or Remcon
  • Military grade milspec phosphated and chrome lined bolt carrier group with MPI tested bolt in either 158 Carpenter Steel or 9310 Steel and 8620 carrier
  • Knights Armament (3) 11-ribbed black rail covers
  • Optional: ARMS #22 HIGH 30mm rings
  • Optional: Knights Armament full sized 600m rear sight and M4 99051 black front sight as back-up irons.