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Sun Project M40A1
  • Manufacturer 
     Sun Project
  • Model 
     Remington M40A1
  • Capacity 
  • Weight 
  • Power 
  • Power Source 
  • Blowback 
  • Hop-up 
  • Shooting Mode 
  • Construction 
     Real wood stock, metal barrel and cocking lever, rubber butt stock


+ Highly upgradable to well over 500fps + Refined finishing with high quality stock + Easily takes a Harris bipod


- Hard to find - Stock spring is too weak for sniping - Sticky trigger mechanism - Sticky magazine BB feeding


An excellent investment for those serious about sniping, though we would highly advise upgrading for any practical use. The beautiful and refined finishing alone warrants owning one.


The M40A1, a derivative of the Remington Model 700 Series, is a true pioneer of modern sniper rifles. The dedicated sniper rifle of the US Marine Corps, the M40A1's life of service began in 1966 when the US Marine Corps ordered 700 for testing. The results were impressive but the wood stock proved to cause weather related problems; often shifting the barrel in its seat and causing other reliability issues. As such, the M40A1 was later upgraded with lightweight McMillan fiberglass stocks which were known for their ruggedness. The entire system was built by US Marine Corps armorers in Quantico, Virginia, USA. In the field, the M40A1 is known for its extreme levels of accuracy with a maximum listed effective range of 800 meters. The US Marine Corps have claimed even higher numbers in battle situations; up to 1000 meters. Muzzle velocity is listed at a whopping 2,547fps.

The M40A1 sniping rifle is a bolt operated, 5 round internal magazine-fed 7.62mm x 51 NATO weapon. The military issue version comes equipped with Unertyl lo-power fixed telescope with a mil-dot reticule pattern (actually civilians can only purchase replicas and cannot own the genuine version). The entire system weighs over 6Kg including the scope.

Chavez takes aim with his silenced M40A1 in Clear and Present Danger Sun Project of Japan has faithfully reproduced the M40A1 in a highly realistic package as shown in the pictures here. Made with a real wood stock and all metal barrel, Sun Project's M40A1 weighs a hefty 3000g, though it feels much heavier due to its very balanced weight distribution. The butt stock is made of high density rubber. The construction is top notch and the gun feels as solid as a baseball bat with no squeaks, jiggles, or flex whatsoever.

Details on the M40A1 are abound, like the original Remington markings inscribed on the left side of the receiver. Each handmade M40A1 is also serial numbered. Only several thousand of these beauties were ever made and Sun Project has recently discontinued production of the M40A1. The underside of the gun also sports a large metal plate that accommodates the grooved trigger and trigger guard. The only complaint we have is that the trigger action is not as smooth as we would have hoped due to a primitive trigger mechanism. The wood used for the stock is high quality with very nice grain patterns, and the all metal barrel's finishing is anodized, not painted, thus providing some level of scratch resistance. The M40A1 does not come with scope mounts or the scope, which are both purchased separately. Pictured here are scope mounts manufactured by Sun Project and a 4-12x40 riflescope by RedEagle.

Cocking the gun is a matter of pulling the light action bolt back all the way and pushing it forward to chamber the next round (26 in total). The safety is located rearward of the bolt lever and rocks back and forth, where the former deactivates the trigger. One annoying occurrence is that cocking the bolt in a frenzy during the heat of the moment often brushes the smooth operating safety back as well; a situation remedied by some deliberate practice to specifically avoid this. Once the magazine is empty, the bolt is not allowed all the way forward thanks to the stopper stem on the magazine which sticks up and prevents the nozzle from being chambered - a sign that it's time to reload. The magazine itself is a removable all-metal entity that we found not all that reliable in feeding BBs when fully loaded with 26 BBs; our experimentation found 15 to be optimal.

The magazine is removable and holds 26 rounds
Beautiful trademarks inscribed in guns body
All metal trigger assembly

Stock, the gun relies on spring power capable of shooting at 1.7joules; 385fps using a 0.25g BB and 430fps using a 0.2g BB. This is significantly more power than stock electric weapons and makes this a realistic sniper weapon in the realm of airsoft. The high-precision barrel possesses a non-adjustable hop-up and to maximize power, the inner barrel extends out to within 5mm of the outer barrel's tip (see picture above). 0.3g BBs are the recommended weight to counter the fixed hop-up. Firing the M40A1 emits a loud "twang"; something that really took away from the experience despite the 1.7joules of power that it represented. Upgrade options include a 200% spring set with steel cocking tube promising close to 470fps, or a gas system conversion that provides even more mind blowing power.

In deciding to upgrade our M40A1, we considered the fact that the 200% spring would stiffen the cocking action and therefore opted for the more high-end gas conversion.

For those of you with sharp eyes, you may already have noticed the valve stem located on the right side of the bolt. The gas conversion system replaces the entire spring and bolt assembly and installs a gas chamber within the bolt itself. The trigger assembly itself is also modified with a hammer system that allows the release of gas upon trigger pull. Following the conversion, the bolt travel is much shorter as you can see in these photos - the travel is quite short, smooth and light (since there is no spring to work against). Unlike in stock form where you needed your entire right arm to cock the gun, you can now pull the lever back with two fingers and push it back forward with your thumb - in one quick motion.

Stock with the spring mechanism, the bolt can be pulled back twice as far. The gas conversion retains the stock cocking lever and replaces the metal alloy cylinder with an aluminum model. Another flaw we noticed is that the hammer is extremely sensitive and misfires can occur if you push the bolt forward too hard. Again, practice makes perfect.

In it's unmodified form, the gas conversion system takes HFC134a gas to output approximately the 430fps (no power increase from the spring mechanism). Through custom modifications and professional porting work, the system can accommodate HFC22 or even Red Gas. Our particular M40A1 was tuned as such and each shot generates enough gas to form a bulb of cloud just beyond the muzzle; enough to blind our sights for a split second as we're peering through the RedEagle scope. The report has also been converted into a nice "Pock", which coupled with the gas effect produces quite a nice experience.

Despite the benefits of this conversion, the gas chamber is relatively small and we are only able to get approximately 7 shots from each full charge of gas. Tuning the gun to get more shots per charge is possible but there is a power tradeoff. But then again - the real steel version only has a 5 round capacity.

Note valve on bolt cover after gas modification
The bolt moves back smoothly and is easy to pull in stock form
The M40A1 is extremely powerful after upgrades

On the field, the performance is quite astounding with bulls eye accuracy at 80feet. Accuracy degrades to 2 inch groupings at 120 feet and 8 inch groupings at 160 feet. Anything beyond that and it becomes challenging to nail a piece of A3 size paper, though still very possible to hit a man-size target. Having said this, the BB still hit our cardboard target with enough force at this distance to penetrate it with a clean "pop:. All our tests were conducted with 0.43g BBs and Red Gas. Hearing a BB whiz by is quite unnerving as the high velocity generates a high pitched buzz and the BB cuts through the air.

So how much power does all mean? The conversion means that even 0.43g BBs can be used and with Red Gas, the result to the right is easily achievable in one clean shot from 1 a distance of 0.5 meters. We leave it to your assessment of how tough an HFC22 canister is.

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