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The U.S. Marine Corps M40 Rifle

By Scott Stoppelman

In recent years there has been a growing interest in precision and tactical rifles. Sometimes referred to as “Sniper” rifles, several major manufacturers offer their own version under various titles and sporting one degree or another of accoutrements. Most are basically a heavy barreled.223 Rem. or .308 with either an oversized wood or synthetic stock as they come from the factory.

It is then up to the owner to add the scope of their choice and other embellishments like perhaps some sort of bipod system or maybe getting a trigger job if needed and maybe add a sling. Some outfits come complete with everything the shooter might require like Remingtons TWS, or Total Weapon System, which is built around the excellent Model 700 PSS rifle.

Most tactical scopes range from 3x-9x to 6x-18x, with the most common perhaps being a 3.5x-10x or even a fixed lOx.

Though most shooters will never use their “Sniper” rifle to shoot at anything other than paper, they are mostly a joy to shoot. With usually good triggers and ample weight serving to reduce felt recoil, and with the high quality barrels present on most of these rifles, 1/2 MOA groups are a realistic goal without too much trouble. This is possible even with select factory ammunition. One of the best and the yardstick by which other factory ammo is measured is Federals “Gold Medal Match”. A personal Rem. PSS .308 with its 26” heavy barrel and topped with a 4x-12x Leupold scope easily makes the half inch mark with a number of handloads and with the 168 grain “Gold Medal” load as well.

Brief History

So called “Sniper” rifles have of course been around for a long time, in fact since rifles have been used in combat they have been used for sniping when necessary or when the opportunity presents itself.

Scope sighted rifles didn’t really come to the fore until WWI though they had been used as early as the Civil War. World War II saw the use of 1903A1 and 1903A4 Springfield rifles as well as Ml Garands as sniper rifles. These fine rifles served well in the Korean conflict and even into Vietnam but the Marines saw the need for a standard issue Sniper rifle of new design rather than just modifying existing service rifles which while effective were becoming obsolete.

During the early years of the Vietnam War the Marines had been using scope sighted Winchester Model 70 rifles that had been in supply for hunting and competition purposes for some time. However, the Corps wanted a new rifle built to their specs and chambered for the newer caliber 7.62 NATO or .308 Win, which was the standard service rifle cartridge of the time, instead of the .30/06 of the M70.

Marines Choice

Therefore in 1966 after evaluating entries by several rifle and scope makers the Marines signed a contract with the Remington Arms Co. to supply 700 Model 700 rifles with the Redfield 3x-9x Rangefinder scope.

Designated the M40 by the Marines, the rifle was in simplest terms a Model 700 with sporter style non checkered walnut stock and a heavy barrel in .308 Win. Where it differed from the commercial version of the ADL model was in the addition of a magazine floorplate like the BDL. The stock style though sans checkering was pure sporter, including the monte carlo comb and cheek piece popular at the time.

The barrel was 24” long and measured .830” at the muzzle thus making a fairly heavy barrel by sporter standards though no heavier than a varmit barrel.

My first bolt action hunting rifle bought in Alaska in 1968 was in fact a 700 ADL in .308 that served me well for many years.

Only a limited number of these rifles were ever made, less than a thousand total for the contract, and a number of them were damaged or destroyed in battle or modified to the newer M40A1. There are so few still in existence outside of the military that the chances of seeing one, say on the used gun market, are essentially nonexistent.

While reading the excellent and comprehensive book, The One Round War by Peter Senich, it occurred to me that one could, with the proper components and a bit of work, have one’s own M40.

Looking for a Few Good Parts

The first thing to do then would be to collect all of the necessary parts for this project. A 1960’s vintage 700 rifle would have to be found.

A Model 700 with a 5-digit serial number was found at a gun show for a reasonable price, and though the Marine contract rifles were of the 6-digit serial number range, the action is the proper style with the short bolt shroud. The gun was itself chambered in .308 Win. as well though it didn’t have to be as long, it was a short action with the proper size bolt face. Also of note, the action has the clip charger slot cut into the rear bridge, a feature that was dropped in 1964 on commercial rifles but was present on all Marine contract rifles, though it is styled a little different. But it was not my intent to build an exact duplicate to pass off as an original later on, rather to build a reasonable facsimile of a fine shooting rifle. In other words, the building of this rifle is meant to be more of a tribute to the rifle itself and its users than for any gain other than personal use and satisfaction.

Stock Work

With an acceptable action and stock in hand the work begins. The 700 stock of this era, early 60’s, had what many consider something of an abomination, machine impressed checkering. Here the diamonds are pressed into the wood rather than being against the hand like cut checkering. While the design is attractive enough, its utility as a grip enhancement is almost useless. For the M40 the “checkering” would have to be removed. This may seem a little daunting at first but requires not much more than a lot of patience and elbow grease. After stripping the finish off with a chemical stripper I began by giving the stock a thorough scrubbing with cleansers and bleach to remove oils and stains. Lots of hot water is used to rinse with and it actually helps to back out the diamonds from the grip and forearm. Then after drying out a bit, scrapers and chisels are used to scrape away the “checkering” pattern. Care is called for here so as not to put deep scratches in the wood as they can create a lot of unnecessary work. Eventually if all goes well the alleged “checkering” is gone with maybe only a trace of the old outline showing if one looks really close. But if you can see it you’re too close!

The stock is then sanded down in the normal way and either stained and oiled or maybe just oiled. I chose to stain this stock for personal preference. This is followed up with many coats of boiled linseed oil to achieve what the Marines refer to a “dull oil finish”. The rifle as acquired had the proper aluminum buttplate called for so no problem there.

The M40 has a hinged magazine floorplate for its box magazine as on a BDL but the ADL stock has no mortise for one so one will have to be let in. This is a fair bit of work and would take too much ink to describe in detail here, so suffice to say that much care must be taken or the results may be less than gratifying.

The BDL floorplate assembly was purchased new from Brownells Inc., that great supplier of gunsmithing equipment, gun parts and accessories. It comes with a paint-like matte black finish which is suitable for the purpose and is made of aluminum per spec. Also acquired from Brownells were military style 1 1/4” non-detachable sling swivels to replace the detachable studs the rifle came with.

The Barrel

The Marines called for a 24” heavy barrel with 1 in 10 twist to shoot the M118 Match ammunition, which used a 173-grain full metal jacketed bullet. To build this rifle a barrel was purchased again from Brownells that was very close to spec. As cut to 24” it is right at the proper .830” muzzle diameter.

The chrome moly barrel, made by Shilen was pre-threaded and short chambered.

At this point the gun must be handed over to the gunsmith to have its existing 20” carbine barrel removed and the new heavy barrel installed and headspaced and then off to get the proper finish, in this case parkerizing. The M40 action and barrel had a greenish color common to many U.S. service rifles seen, but the bolt assembly was given a flat black finish.

The barreled action must now be bedded to the stock. This is done in the normal way with Brownells Acraglass Gel. The M40 rifles left the factory unbedded by glass but instead were referred to as “hand bedded” by Remington. Subsequently many if not most of the rifles were glass bedded by armourers to help prevent impact shift caused by the shrinking and swelling of the stock in climate changes. Also the barrel channel had to be kept open by any means possible to keep the barrel fully free floating.

The Scope

The scope chosen by the Marines to meet their specs was the Redfield 3x-9x Accu-Range that was already in use by the public and had a good reputation and seemed to best fit the needs of the Corps.

This unique scope uses what Redfield referred to as the “special fine crosshair” reticle and the so called “tombstone” system that employs on the right hand side of the view circle a range finder marked in 50 yard increments out to 600 yards. As the power ring is increased from 3 to 9 power the “tombstone” begins to slide out of sight until only the top portion is seen. It also utilizes a 2-wire grid near the top of the view circle that represents 18”. The method being that the viewer places the two stadia wires on a man sized target and increases the power until the two lines are spaced about equal to a mans torso from chin to belt, then reads the range on the “tombstone” on the right. The viewer must then make the necessary calculations for hold, over or under, to make the shot for that range. The M40 was usually sighted in for a dead on hold at 600 yards.

Such a scope was found and purchased from a used sight and scope dealer for this project and then sent to ABO/USA for cleaning and adjustment. ABO/USA is the authorized repair facility for Redfield products since Redfield is unfortunately no longer in business. Cleaning and adjustment was done for only a shipping and handling fee. These scopes are a bit scarce also and it was a real break to find one rather easily. This specimen has the gloss black finish of the commercial model whereas the M40 scope was anodized green to match the barreled action of the gun. Some later M4Os were furnished with a scope that was finished in matte black, and were called 2nd Generation scopes.

The scope is mounted on a Redfield Jr. one piece base in one-inch split rings, all of matte finished blued steel just like the original. The base and rings have changed a little since the 60s but it’s basically the same rig.

Carrying Case

M40 rifles were issued to the Scout-Sniper teams in a hard plastic carrying case made by Protecto Plastics of Pennsylvania. The case used had a center mounted two pc. handle and three evenly spaced lockable latches. The interior was lined with foam on both halves and the case measured 3.5” deep by 9” wide by 46” long, just large enough for one rifle, cleaning kit and a few accessories.

What’s most interesting about this case is that it is still available today under the Hoppes brand name, still being made by Protecto Plastics. The only difference that’s at all evident is the color of the case is now black where it was brown as issued, and the interior foam is of a different configuration.

Final Assembly

Now with all of the various components together and properly finished it’s time to assemble the rifle and scope and see what it will do.

Putting the rifle together is no trick of course but a problem was encountered when trying to mount the scope. It was found that there was a noticeable difference in the height of the front and rear rings. So to rectify this I turned to a scope lapping kit purchased from Midway/USA. After running the lapping bar through the lightly snugged rings a number of times and checking the work often the proper height was attained wherein there was no difference in height between the two rings. If this is not done it is possible to bend the scope when the rings are tightened down thereby damaging the scope.

Satisfied with that task the rest of the package is put together in the usual way.

Shooting the Marine Rifle

Original Marine Corps specs called for a minimum capability of 5 shots in 1 inch at 100 yards, or one minute of angle, with the M118 Match load. This shouldn’t be too hard to accomplish with today’s ammo and components. The M118 load was replaced in the 80s with the M852 load that uses the 168-grain bullet instead of the 173 grain original.

Since the amount of available components for .308 is almost endless the quest will be to approximate the original round, therefore it is hoped that the 175 grain Sierra Match bullet will work out well.

Before getting serious with the best components and trying to shoot for groups the barrel must be carefully broken in using the shoot and clean method. You know the method, shoot a little and clean a lot. For the first 5-10 rounds the barrel is cleaned of powder fouling between each shot and then followed up with a copper solvent to remove all traces of jacket fouling. This method is used for the first 60 rounds or so while never allowing the barrel to get very hot as this will cause problems rather quickly. Plain old Hoppes #9 is as good as any for getting out the powder residue, but to get the copper jacket fouling I turn to Sweets 7.62 solvent. This stuff removes copper as good or better than anything. Instructions must be followed, and it’s nasty smelling stuff, but it do work!

The first range session is always filled with a little apprehension with a new rifle and this was no different. I began to relax a little when the first two rounds landed on the target just 1/2-inch apart at 100 yards, and almost in target center after only a visual bore sighting. This initial shoot-in was performed by the way, with the Rem./UMC 150-grain ball load that I have a lot of on hand. The last three shots taken that first day were with a proven handload that seems to work well in almost any rifle including bolt gun and M14 style guns. That load is 42.0 grains of 1MR4895 in W/W cases lit by a Fed. 210 Match primer. Those three shots went under an inch. Not spectacular to be sure but barrels seem to get better as they go if they are treated right.

The rifle has been to the range a number of times now and does better every time if the shooter does his part. I was happy to see the Federal Match 175-grain load do well. Two groups of five were shot on the second trip to the range and both went under one inch. While it’s true that factory ammo is much better now than ever before it is still a thrill to see it shoot that well. Six rounds from the handload mentioned before went into five-eights of an inch, on the same day, not bad.

A single box of M118 Match was found at a local gun show and was soon run through the rifle. Results sad to say were not that great as groups were hard to achieve and the primers were all cratered possibly indicating slightly elevated pressures, but as it is hard to come by anyway and the gun seems to shoot so many other loads so well that it really wont matter if it doesn’t like that particular lot of ammo or not. In other words, who cares?

As is the case with my Rem. PSS.308, Hodgdons Varget powder is showing great potential. Loads with 43 and 45 grs. are grouping under an inch for five rounds at 100 yards. 1MR4064 has worked well for a couple of loads but is not as consistent as either 1MR4895 or Varget. Every gun is a law unto itself so it always pays to try various powders.

All group testing was done from the bench at 100 yards. My local range has targets up to 300 yards and I will shoot the gun at that range but there is not much point in putting it here as groups always open up at that range. If the shooter is not up to snuff that day it will definitely show on the target while not being the fault of the rifle.

The idea here was to more or less replicate what would otherwise be an unobtainable rifle, and make it shoot to the specs laid out by the Marines back in 1966. I think I have accomplished this as it shoots very well, and perhaps most fun of all is when someone at the rifle range asks what I’m shooting, I can tell them I’m shooting the Marines M40 Sniper Rifle.

Remington Model 700

Introduced in 1962 the Model 700 was an updated and modernized version of the 720 series of rifles that had been the mainstay of the Remington line for many years. It was designed to go head to head with Winchesters Model 70 but be less expensive to build.

It succeeded very well and has gone on to be one of the most successful bolt action designs ever and is still being made in many different versions and calibers today.

It is a very strong action and Remington made much of its “three rings of steel” claim. Its detractors claim that the small extractor in the head of the bolt is too small and unreliable but this writer’s opinion has never been proven to be the case. Indeed many tests were run to determine if it would be strong enough to compare favorably to other more accepted designs such as the 98 Mauser and others. It held its own with the best of them and failures are almost unheard of. Another claim that many will back up is that of excellent out of the box accuracy. If there is truth to this claim I believe it has more to do with the quality of the barrel than anything else. Every model 700 I have ever owned showed the potential to be a great shooter but not all would do so without a good bedding job. This is a common problem with just about all mass produced rifles however.

The M4Os were built using Remingtons own barrels and served well. The later M40A1 is built with a barrel from Atkinson. The Rem. 700 is of course also the base rifle for most of this country’s police department sniper teams.

Quite a legacy for a model of rifle introduced almost 40 years ago, but then if we look at the fact that the 98 Mauser action that is over 100 now and still going strong, I guess we shouldn’t be too surprised. If it’s good, it stays on.

Cartridge History

The 7.62x51 NATO that the M40 was chambered in was a development of the Army Ordnance department known early on as the T-65. It began as an attempt to get the ballistics of the 30/06 in a shorter case that would permit the use of lighter shorter and more efficient gun mechanisms.

The military did not officially adopt the T-65 until 1954, but Winchester brought out its own commercial version in 1952 and called it the .308 Winchester.

The U.S. military didn’t have any weapons for it until 1957 when it became the official service rifle cartridge for which the M14 rifle was chambered.

The .308 has been hugely successful for a good many years now and is still the one to beat in match competitions around the country, though it is not the only accurate round out there. It is still however the standard round for military sniper rifles. Besides being the M40s cartridge, the 7.62 continued on into the M40A1 and the new current M40A3. Also the Army uses the 7.62 in its own M24 Sniper rifle also based on the Remington 700.

It was recently announced that the Dept. of Defense has adopted a brand new loading for all long-range sniper shooting. This loading will feature the l75gr. Boat-Tail bullet propelled by Alliant Powders Reloder 15. It will be designated the M118 Special Ball Long Range Sniper Round. It will become the standard issue sniper round to be used by all military service branches.

This cartridge is hard to beat in many ways and looks to be with us for some time to come.

References

Inside the Crosshairs- A Snipers Vietnam - Michael Lee Manning

Dead Center - Ed Kugler

Sniper - Adrian Gilbert

The One Round War-Scout-Snipers in Vietnam - Peter Senich

U.S. Marine Corps Scout-Snipers WWII and Korea-Peter Senich

Marine Sniper - Charles Henderson

One Shot One Kill - Charles Sasser and Craig Roberts

Bolt Action Rifles - Frank de Haas, Chap. 39, Ideal Snipers Rifle Rev. Ed. 1984


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