MK12 Mod 0 / MK12 Mod 1 Question

[Rotting]

Might be a ridiculous question, but I'm not entirely sure what the difference is between the MK12 Mod 1 and Mod 0 is. Anyone care to help me out on it? I'm in the process of rebuilding an M16 over into an MK12 and for the sake of being accurate to the name, I'd like to get a positive confirmation.

I've done a bit of searching to verify what the distinguishing marks of the Mod 1 and Mod 0 are, but all I can really see is that the stock is either crane/full, and sometimes the front end kit is different. I've seen some Mod 1s with a full RIS, others using the DBoys 5381 front end kit, but still both have the Mod 1 name attached to it.

Sorry if this is a rather idiotic question. I usually stick to SiGs, so the M-Series rifles are a bit of a paradox to me, but it was getting to expensive to find parts because you know, Canadian market, increased rarity = increased price.

Thanks.

[L473ncy]

I know the handguards are different (both use free float rails however are of different models/brands) as well as the rail mounts.

I believe the scope is also different as well.

[coach]

minor difference noted here: http://en.wikipedia.org/wiki/United_..._Purpose_Rifle

* Handguards: In all cases a free-floating forearm is used, which does not touch the barrel directly. This increases the accuracy of the weapon by removing vibration and pressure exerted on the barrel by the rest of the gun. The first SPRs used PRI Gen I or Gen II carbon-fiber free-float tubes. The SPR/A, SPR/B, and Mk 12 Mod 1 all use the Knights Armament Company M4 Match Free-Floating Rail Adapter System. The Mk 12 Mod 0 uses PRI Gen III free-float tubes. The Gen I and Gen II Freefloat Forearms are combined with the Atlantic Research Marketing Systems #38 SPR MOD Sleeve, while the Gen III Freefloat Forearm, due to its it larger barrel nut, only works with the ARMS #38 SPR PEQ-2-3.

* Sights: The original SPR used an early PRI flip-up front sight with an elevation dial, which has since been discontinued. The Mk 12 Mod 0 uses the current PRI flip-up front sight. The SPR/A, SPR/B, and Mk 12 Mod 1 use the KAC rail foreend flip-up front sight. The SPR and Mk 12 Mod 0 use the ARMS #40 flip up rear sight. The rest of the models use the KAC 600 meter flip up rear.

* Optics: Due to the relative modularity of the system, optics (as well as almost everything else) can be mounted according to the operator's wishes. However, SPRs are most often seen with a 3.5–10×40 mm Leupold LR M3 (SPR/A), a 2.5–9×36 mm TS-30 (SPR/B), or a 3–9×36 mm TS-30 A2 (Mk 12 Mod 0/1) Mid Range/Tactical Illuminated Reticle Dayscope. Night vision devices can also be attached. These scopes usually come with flip open dust covers and a honeycomb anti-glare anti-reflection device. Given Nightforce Optics' NAVSPECWAR contract, it is believed that many NAVSPECWAR issued SPRs will use the Nightforce 2.5-10x24 NXS scope.[3]

* Mounts: A long accessory rail, called a SWAN Sleeve (ARMS SPR MOD or ARMS #38 SPR PEQ-2-3), manufactured by ARMS, is installed, running the length of the rifle. The SPR/A and SPR/B both used the KAC M4 Match FF RAS. Two ARMS #22 Throwlever 30 mm steel rings are used to mount the dayscope. The SPR/A, SPR/B, and Mk 12 Mod 1 use ARMS #22 high rings, while due to the increased height from the SWAN Sleeve, the SPR and Mk 12 Mod 0 use ARMS #22 medium rings. An under-the-handguard ARMS #32 Throwlever mount is used to mount the Harris bipod (the ARMS #42 Throwlever mount is used to mount the Versa-Pod); this features a quick release action.

* Bipod: Originally Versa-Pods (a cheaper Chinese-made copy of the relatively expensive Parker-Hale swivel bipod) were used, but were taken off the system after the initial SPR. Currently, a Harris swivel model bipod is typically used with the SPR, and is sometimes seen with a KMW Pod-Loc tension adjustment device. As mentioned above, the bipod is mounted via a ARMS #32 throwlever device attached to the bottom rail of the rifle's forearm. The ARMS mount is used on both the Mod 0 and Mod 1.

* Suppressor: The OPS Inc. 12th Model SPR Muzzle Brake Suppressor threads directly onto the OPS Inc. muzzle brake and uses the collar to stay centered.

* Ammunition: The SPR is not used to fire standard issue 5.56mm M855 or M193 ball or M856 tracer ammunition. Due to the limits in terminal performance and relatively poor accuracy of the 62-grain (4 g) M855 ball, the Mk 262 Open Tip Match (OTM) round was developed as a more accurate round for the SPR, and manufactured by Black Hills Ammunition. The first production batches were designated Mk 262 Mod 0 and used a Sierra Bullets MatchKing 77-grain (5 g) Hollow Point Boat Tail bullet without a cannelure (crimping groove). Black Hills then approached the Nosler bullet manufacturing company, who made a similar 77 gr (5.0 g) OTM bullet, and Nosler agreed to supply cannelured bullets to Black Hills. The newer load was designated Mk 262 Mod 1. Recently, Sierra added a minimal crimp to its bullet, and this has since replaced the Nosler bullet in the current versions of Mk 262 Mod 1.

[Rotting]

Well that solved a lot of issues.

Problem now being where the hell to find a 3–9×36 mm TS-30 A2 scope, or a clone. Seems 3-9x40 and 3-9x32 are available pretty easily, but that middle ground isn't. Tried staying local with it, since I'm not too fond of doing international orders. Looks like I might be boned on that one. Also seems as though the PRI rear sight is a bit more difficult to find than the PRI front sight. Plenty of makers for the front, the only rear one I can find is DBoys, and jesus I'd like to avoid them. If anyone has some suggestions on that particular style scope or the rear sight, fire away.



Also, thanks, coachster.