Notes: The M-21 began life as the M-14 National Match Rifle, a weapon based on a modified M-14 battle rifle to be used for competition shooting by soldiers. The potential as a sniper weapon quickly became obvious, and further modifications resulted in the M-21. The M-24 is basically an M-14 that has been reworked by Springfield Armory (the original manufacturers of the M-14) and the US Army to be highly accurized, with a match barrel, a walnut stock impregnated with glass resin to resist warping, a reworked, smoother action, and of course, a mount for a telescopic sight or night vision sight.

The M-21, despite the long length of its use, had a number of limitations: the scope mount could take only a limited number of sights, the mount itself tended to be easily knocked out of alignment, it was not issued with a bipod (requiring one to be added later), and the work required to build and maintain an M-21 was expensive and time-consuming. In addition, semiautomatic sniper rifles are generally not as accurate as bolt-action rifles. The M-21 was largely replaced by the M-24 starting in the early 1990s.

However, starting in Panama in 1989, it became increasingly apparent that a sniper team’s spotter needed a better weapon than the M-16A2s with low-power scopes that they used at the time; the spotter needed a weapon with greater close to medium-range firepower than the bolt-action M-24, but one that is still useable as a sniper rifle when necessary. Springfield responded with the M-21 Tactical Rifle. This version of the M-21 uses essentially the same glass resin-impregnated walnut stock as the old M-21, but this stock is modified to have an adjustable cheekpiece and a rubber recoil pad. The barrel is still match-quality, but is heavier than that of the original M-21, and are built by Douglas, Hart, or Krieger. They are made of stainless steel with a matte anticorrosion finish and are 22 inches long and tipped with the standard M-21 flash suppressor. The trigger is a two-stage model. A Harris lightweight bipod adjustable for height and cant have been added. The M-21 Tactical Rifle uses the Springfield Third Generation scope mount (designed to be able to mount all US Army, most US military (or other branches), and most NATO-compatible optics. The telescopic sight provided with the M-21 Tactical Rifle is the Springfield Government Model 4-14x scope.

The M-25 is a limited-production sniper weapon produced for US Army Special Forces and Navy SEALS; it was actually developed by Springfield with the help of notes provided by the estate of the late Carlos Hathcock, perhaps the best sniper the US Marines have ever produced. It is basically an M-21 sniper rifle revised to a new standard, and was at first called the "Product Improved M-21, or M-21 PIP." The weapon uses a Krieger heavy match-grade 22-inch barrel tipped by a low-profile yet efficient muzzle brake designed by Hathcock before his death. This muzzle brake can be removed, revealing threads which allow the attachment of most silencers and suppressors used by SOCOM. The trigger is a match-quality trigger adjustable for pull weight and overtravel. The stock is a specially-made McMillan stock, again designed using Hathcock’s notes; this stock is built of Kevlar-reinforced fiberglass, and has a rather unusual shape with a very low buttstock body and a semi-pistol grip. Atop the buttstock’s body is comb with a highly-adjustable cheekpiece (adjustable both vertically and for position along the stock). The buttplate is padded and is adjustable for length of pull, height, and angle. The M-25 uses a special gas piston which increases the reliability of the weapon while also reducing recoil somewhat. The M-25 has no iron sights, but it is equipped with a MIL-STD-1913 rail for universal mounting of optics. (Reputedly the standard scope for the M-25 is a 10x Bausch and Lomb of unspecified type, but SOCOM troops could and probably do mount whatever works best for the sniper and in the situation at the time.) The M-25 is equipped with a Harris-type bipod adjustable for height and cant.

The M-25 is not any sort of replacement for the M-24; it is made for a specific requirement for a light, high-capacity semiautomatic sniper rifle for SOCOM. The first prototype M-25s (at that time called "XM-25") were first used during Desert Storm, and they have seen a lot of use in Afghanistan, Iraq, and who knows where else. It should also be noted that in many cases, the M-25 has been supplanted by the newer Stoner SR-25.

Recently, the M-25 has also been sold in a modified form on the civilian market; in this guise, the M-25 is more commonly known as the White Feather (an homage to Carlos Hathcock’s trademark symbol). The civilian version uses a different muzzle brake, and the stock is somewhat different in that it is not so minutely adjustable. Iron sights are available at the buyer’s option. They are normally sold only with 10-round magazines, but can accept 20-round M-14/M-21 magazines. However, the White Feather also has something the military M-25 does not have – a signature block bearing Hathcock’s White Feather symbol and a facsimile of his signature.

Twilight 2000 Notes: The M-21 remained in large-scale issue, due to a lack of M-24s and other such weapons; the M-21 Tactical Rifle was in service in lesser numbers with the regular US Army, but rare in National Guard and Reserve units. The M-25 is even rarer; in fact, its official designation is still "XM-25," and it never got wide issue, even amongst US special operations units.

Merc 2000 Notes: Large numbers of M-21s were sold to various allies of and allies of allies of the US, but the M-21 Tactical Rifle was not, and the M-25 was certainly not.

Notes: This highly-modified Remington 700 began to equip the USMC in the early 1970s. They are hand-modified from stock Remington 700s, using a glass fiber stock, a heavy match-grade barrel, no iron sights, and scope mount for a Unertl 10x telescopic sight; when the USMC armorers at Quantico are done, the M-40A1 only looks like a Remington 700. The former users of this weapon are legendary, including Carlos Hathcock.

The Marines actually only buy the receiver assemblies from Remington, since the armorers at the RTE (Rifle Team Equipment) Shop intend to modify pretty much everything else or fit the rifles with custom components bought from other manufacturers (and the receiver assemblies are heavily reworked as well). Barrels for the M-40A1 are heavy, match-grade 24.1-inch barrels made by Hart, Atkinson, or H-S Precision; they are intensely-inspected and tested for quality. These barrels and the receiver are placed into a McMillan fiberglass composite stock, with the action being glass-bedded and the barrel free-floating. The trigger unit used is a modified Winchester 70 trigger group. The scope mounts are essentially proprietary to the Marines; they are specifically designed to use a special version of a 10x Unertl telescopic sight, or night vision scopes used by the US Marines. There are no iron sights, nor any provision for mounting any.

The M-40A1 PIP was originally going to be called the M-40A2, but because the M-40A3 was to follow close afterward, and because the M-40A1 PIP was a heavily reworked M-40A1 instead of being a brand new weapon, the M-40A2 designation was not used. The M-40A1 PIP uses a new McMillan stock with a deep pistol grip wrist, adjustable cheekpiece, and installable spacers for adjusting the length of pull. The new stock is much lighter than that of the original M-40A1. The entire rifle was worked over to improve it and refurbish it. Though a great improvement over the M-40A1, the M-40A1 PIP was basically meant to only be a stopgap weapon until the M-40A3 was produced in large enough numbers, and it did not appear in large numbers.

The new standard sniper rifle of the US Marines is the M-40A3. As earlier M-40s rotate in for repairs, they are being replaced by this version of the M-40. As with the M-40A1 PIP, the M-40A3 was to have been designated the M-40A2, but the improvements and modifications made were so great that it essentially as a different rifle, and it was designated the M-40A3 instead. Changes include the use of a new McMillan-built stock, with a padded buttplate adjustable for length of pull, a stock with an adjustable cheekpiece, a MIL-STD-1913 rail for optics mounting (though the standard scope is the same, except for being built by US Optics instead of the now-defunct Unertl company), the incorporation of a Harris lightweight bipod adjustable for height and cant, and a trigger unit adjustable for pull weight and pull length. The action is also, to a limited extent, adjustable for bolt pull length (and begins with a shorter bolt pull than the M-40A1). The barrels are still 24.1 inches long, but built of better steel, and the muzzles are threaded to accept a suppressor or muzzle brake. The MIL-STD-1913 rail is mounted so that it tilts 30 degrees upward in the direction of the muzzle, to facilitate long-range shooting. The stocks are normally OD Green; metalwork is also finished in OD Green, using Robar Teflon or Birdsong Black T anticorrosion finishes.

Twilight 2000 and Merc 2000 stories: The M-40A1 weapons are still in large-scale issue in the Twilight 2000 timeline (as well as the M-40A1 PIP, to a lesser extent). The M-40A3 appeared late and was always in short supply during the Twilight War.

The TAC series is designed, depending upon its iteration, for tactical police use to military applications. The action is based upon the Remington 700 series, but the design diverges from the base 700 action quickly.

The action is built of hardened 17-4 stainless steel, with an action face almost perpendicular to the bolt axis. Tolerances have been made extremely tight, with critical component having only 0.0005 inch of play in them; they are then hand-fitted and modified further if necessary. The bolt is even tougher, being made of hardened 9310 steel; it also has spiral grooves cut in it to automatically remove most sand, water, and dust when it is cycled. The extractor of the M-700 is replaced by a Sako-type claw extractor, heavily modified into a design exclusively McMillan’s. The standard TAC series comes with Parker-Hale bipod (adjustable for height and cant), but the mount allows the substitution of virtually any sort of other bipod. The stock is a synthetic McMillan stock with an adjustable cheekpiece and a Pachmayr Decelerator recoil pad on the butt. The semi-pistol grip on the A5 stock is especially deep. The trigger is not adjustable, but is factory-set at the lightest touch which is generally acceptable by most snipers for a non-adjustable trigger.

The TAC-308 Standard is designed primarily for urban tactical engagements and for use by marksmen who are not trained snipers. The stock used is a McMillan A3 stock, normally gray in color, though other colors are available; it is finished in Robar ROGARD. The butt has removable spacers to adjust the length of pull. Barrels are Schneider-built and are heavy in profile and also match-quality, with a length of 20 or 24 inches. Feed may be from an integral box with a hinged floorplate or from a box magazine (but not both). Trigger pull weight is set at 2.75 pounds. A muzzle brake is an option, as is a conventional flash suppressor, a target crown, or even a suppressor. No iron sights are provided, but the receiver is topped with a MIL-STD-1913 rail.

The TAC-300 and TAC-338 (both collectively known also as the TAC Magnum) are magnum versions of TAC-308. The .300 Winchester Magnum uses a 26-inch heavy match barrel, while the .338 Lapua Magnum uses a 27" barrel of the same specifications. A folding-stock version will be available in late 2007, though the rifle cannot be fired with the stock folded (it is only a storage option). The TAC Magnum can use a muzzle brake (the muzzle brake is in fact standard on the TAC-338), flash suppressor, or target crown. Again, no iron sights are provided; the receiver is topped by a MIL-STD-1913 rail.

The TAC-50, though it appears externally quite different from the TAC-308 and TAC Magnum, is internally essentially same (sized up for the .50 Browning Machinegun round). Though the TAC-50 is technically an antimateriel rifle, it is included here for completeness. It is sold primarily to military forces (who remain unnamed) and certain police and government agencies. The barrel is 29 inches and tipped with a standard muzzle brake, with no other muzzle options being available. Feed is exclusively by detachable magazine. A takedown version also exists, which has a quick-release stock and barrel.

Notes: Based on their Genesis Hunting Rifle, the Genesis Tactical Rifle is based on the tried-and-true Remington 700 action. The stock has been replaced with a McMillan synthetic stock, usually with camouflage patterning or coloring to the order of the customer. The barrel is a glass-bedded floating heavy match barrel, normally 20 or 24 inches, though other barrel lengths can be had if desired; the barrel is also target crowned. The trigger is reworked to fire with a light touch. Instead of a MIL-STD-1913 rail, the scope rings are set in with dovetails, a much more solid mount. The recoil lug of the Genesis is oversized and precision-ground, and the bolt is squared and trued. Metalwork is finished in Lauer Custom Weaponry Duracoat (black or OD Green). The view of many snipers is that while the GTR is incredibly accurate, it is too light in weight and the trigger pull too light. The standard chamberings for the Genesis are listed below, but Patriot Arms will build a Genesis to order in virtually any caliber.

The Revelation is basically a Genesis "taken to the next level," with far tighter tolerances, more expensive and better-quality components, and generally manufactured to a higher standard than the Genesis. (In real-world prices, you would also pay far more for a Revelation than you would for a Genesis.) The barrel is similar to that of the Genesis, but of better quality, and is also pillar-bedded using stainless steel pillars. The parts of the action are hard-chromed and operate very smoothly. Stocks are of McMillan make, but Patriot Arms will build the Revelation with any sort of McMillan stock the buyer desires. The bolt knob is enlarged, and claw-type extractor is added to the action. The metalwork’s finish is in two chemically different layers to increase corrosion resistance. The trigger unit is a fully adjustable one made by Shilen. As with the Genesis, Patriot Arms will make the Revelation is virtually any barrel length or caliber desired, but the standard ones are listed below.

Twilight 2000 Notes: These weapons do not exist in the Twilight 2000 timeline.

Merc 2000 Notes: The Genesis is not available in large numbers until 2005; the Revelation is not available until nearly 2007.