Designated Marksman Rifle Build

Over the years I have read numerous Designated Marksman Rifle build threads, and rightly so. DMRs are intricate, often very expensive builds and every one is just a little bit different. Now I’ll admit up front, I’m no gun smith and all my internal upgrades were done by someone who was. Nevertheless, for those who are interested, this is my DMR build.

Why a DMR?

My first AEG was a Classic Army G36. It had great reliability but lacked in range. Airsoft battles in those days were small and low speed, often involving less than 30 people save for a once annual event known simply as “Invasion” which involved over a hundred. In my mind, the perfect rifle for me was one that could out-range everyone else. That way I could engage before I was within range of the enemy and ultimately win more games. I was well aware of the local field rules that DMRs must replicate the real steel gun as close as possible and that they were to be semi automatic only. With these in mind, i set out to find the perfect real rifle to base mine off of.

I chose to model the Navy’s Special Purpose Rifle.
This rifle was originally designed for the SEALs who desired a rifle shorter than, but more accurate than the M16. Later variants of the SPR were designated the Mk. 12 and it had 3 variants. One of the major reasons I chose this rifle was that it accepts NATO STANAG (M4/M16) magazines. This would enable me to share ammo with any of my teammates that ran an M4 or M16 platform weapon. Today, there are a few companies that sell the SPR or Mk12 as a gun although these did not exist when I built my gun. If you want to build an SPR I would recommend you start with one of these guns as most of the external work will be done for you.

My Build

My SPR began its life in the form of a G&G GR-16. This is essentially an m4 with an m16  stock and at the time it was cheaper than the full length M-16 variant. I replaced the front end with an Echo 1 SPR front end conversion kit. I then added a G&P SPR suppressor (found at Uncompany) and a Nikko Stirling 3-9×42 red dot scope on extra high scope rings. Finally, I added a replica Harris bipod, a replica KAC vertical foregrip, a Matrix stock cheek pad, and a Daniel Defense rail mounted sling adaptor.

Internally, my tech replaced the gearbox with a Matrix drop in high torque gearbox wired to the rear and modified it to have a more efficient air seal. This is an all in one upgrade component that saved alot of hassle as I knew all the components were designed to work together. He also installed a Prometheus 590mm tightbore barrel, Matrix high torque motor, stronger spring, and a Matrix mossfet              switch. I power my SPR with a large type 3600mAh 9.6v battery.

Would I Build it Again?

Absolutely! This build yielded a wickedly accurate rifle because the FPS is so consistent. Rarely does it vary more than a few FPS in any group. This consistency is what enables me to know where a round is going to go before I fire it, and henceforth makes me more accurate than a standard AEG which has wider variance in FPS.

I would make two changes if I built this rifle again. First, I would spend the extra $100 for a fiber handguard. This would significantly lighten up the front of the weapon, which is currently quiet heavy. Also, I would replace my scope with one with an illuminated mil-dot reticle. The reticle on my scope is a simple illuminated cross which works great in low light but gives me no reference when I am trying to “dope” my gun in any direction. A mil-dot reticle or other windage/elevation estimation type reticle would help quite a bit.

My Experience:

I unveiled my SPR in 2010 at Invasion 5 on the second day of the op. I was with the civilians and we were tasked with holding the town of Caen against the tan invaders. My rifle excelled at picking off targets that thought they were safely out of range and I enjoyed quite a bit of success in that battle. I employed my weapon again late in the game and it made pushing the tan back into Coleville from the airport no more difficult than sweeping a dusty floor. However, I was not able to effectively deal with close in threats or large groups of enemies as well as I would have if I had employed a different weapon. The weight of my SPR is manageable but it is heavy and cannot be shouldered for very long before fatigue sets in. All said and done, my SPR is the DMR I dreamed it would be, but it is not a miracle gun and since then I have turned away from the designated marksman position in favor of being a support gunner. However, my SPR remains a prized arrow in my quiver of airsoft guns.

Update: Since the writing of this review, I’ve sold my prized SPR simply because airsoft gun technology has evolved to the point that I can get the same range in a shorter, lighter package. I do still enjoy the SPR concept and look forward to building another in the future.

2 Replies to “Designated Marksman Rifle Build”

  1. Nice article Dirtpro! I’ve tossed around the idea of building a DMR or Sniper, and settled on the DMR. I haven’t gotten started yet (still collecting assault rifles and pistols), but I’m getting my hands on a rifle this week that might make the perfect base weapon. Your article comes at a perfect time.

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