Anatomy of a Shooter: The Ultimate Milsim Primary? Recoil Mk-18 Mod 1

This is my Rifle, There are many others like it but this one is mine…

Well, actually what you have is a smooth bore low powered air weapon relying on a combination of the Magnus effect and centrifugal force to attain any kind of accuracy. A rifle it certainly isn’t, and a weapon system in only the very loosest sense of the phrase. There are many terms we use for these expensive toys, some prefer RIF (often used to describe both RIFs and IFs), Gat, Shooter, BB Guns (A term the older amongst you would have used back in the 90s), Long/Short, Blaster (Used by the inimitable Gearmonkey of S23 fame) and indeed the one you’ll find me use most often, Replica.

I feel replica sums up perfectly what they are, they pretend to be something they are not. Some things they copy very well, others they do not. It also sounds a little less serious than some of the other terms although blaster is another favourite of mine. The fact is you can call it what you want, but understand why it’s given a certain name and you’ll be better equipped to deal with the questions an outsider to Airsoft might have.

You can’t go to an airsoft game without seeing a Mk18, it’s rapidly becoming the generic MilSim “Operator” primary weapon of choice, followed closely by the Heckler and Koch 416.

There are many manufacturers offering a Mk18 type replica, From the notable G&P to the exceptional look of the VFC. The cheap and cheerful CM16 by G&G to those who choose to create a fully custom Systema PTW with a Genuine Daniel Defence Mk18 RIS.

I’ve gone somewhere in the middle, it’s not a perfect build… there are connoisseurs of the military replica community who can put my offering to shame. If your after ideas and inspiration then look no further than The Reptile House… the collection of replicas put on display through his personal builds and those he showcases are truly masterpieces. The attention to detail is a league above what you’d see in my armoury, anyway… I’m sure most of you are avid followers of his blog but if your not, head over now and have a look.

So without further ado, I present to you the Mk-18 Mod 1 (ATRG Style)


Built around a Tokyo Marui (Of course) SOPMOD Recoil Shock with a 10.3″ barrel, the parts internally are largely stock components. I’m not a massive believer in heavily modifying something unless it’s performing below its expectations. You can literally spend thousands on “upgrades” with no noticeable performance gains. Better to spend a little on those few things you’ll find the benefit from and save your money for decent ammo and game fees.

One of the few components I did jump on the hype train for was the BTC Spectre MOSFET, this was recommended to me by a good friend who is only known to most by his Zero In name “SniperJesus” or his IG handle “sj_asc” he’s one of those rare individuals who shuns the limelight and prefers to showcase his truly groundbreaking work very rarely on his IG account.

So the Spectre wasn’t solely bought because it’s seen as an “essential” in fact I’ve run Recoils quite happily without them for a long long time, My 416 never had one in it and ticked along quite nicely. The main reason was the 3 round burst and the replacement of the mechanical trigger which is always something I look to replace with some form of FET. Aside from this I’ve added an Eagle 6 M100 spring (specifically designed for the travel length of the Recoil Shock Gearbox) a Prometheus purple hop (hype train choochoo!) and a Prometheus 6.05 Returner barrel. The gains are there, but marginal. The best performance per pound item is without a doubt the spring, which although any seasoned player will tell you that FPS doesn’t equal range, it certainly allows heavier ammo to be used with the right hop set up. And heavier ammo certainly does equal range, plus it gets your shots down range a lot quicker.

From the rear of the Mk18 we start off with a Magpul CTR stock, this one having been on Andy S23’s PTW base Block 1.5 M4 for a long time. I’ve kept his worn paint job on the stock as you can’t fake a decent bit of wear and it fits perfectly with the look of the rest of my Mk-18. This does have an early version of the extended butt pad but unlike many Recoils this does not host a LiPo, having changed my replica to a front wired set up some time ago.


Forward of the buffer-tube you’ll see a CQD type sling plate, this having been sourced from a DEVGRU that happened to be split down for parts… Echigoya happen to make a fine alternative to this now and indeed having owned both I’d say the aftermarket plate is the better out of the two. Either way, this sling plate is probably the best sling point available for a recoil, properly fitted it is strong, won’t budge and allows left or right handed use with many 1 or 2 point slings.

Moving onto the receiver, the top rail houses a repro Knights Armament 600m back up iron sight, rarely used but zeroed for 50m should it be needed. Over the top of this I currently have yet another repro item, An ACOG TA31 with an RMR Sitting atop for close range engagements, the sight itself wasn’t my first choice but I was able to “try before I buy” with this particular sight and the eye relief although short wasn’t as poor as most reproduction ACOGs.


The ACOG is also zeroed for 50m with the RMR zeroed for 20m. I also have a replica tennebrax killflash purely because A £4 killflash is easier to replace than a £80 optic. The ACOG is a great looking sight and offers me the ability to spot targets at range and take those longer precise shots where spotting the fall of your shots is essential.


Another sight I’m a massive fan of and what would have been seen on this replica until recently is the Holosun HS403C red dot sight. A very good AimPoint T1 styled sight with a lot of the benefits but not the price tag of real steel optics. In fact a lot of real steel shooters are using wallet friendly optics all over the world, although if my life depended on it I’d stick with the AimPoint T1/2.

I have also replaced the mag release with a D-Boys Ambi model and the trigger pin with a laylax one that shouldn’t move at all!


Next, the bottom of the receiver… this is the one part people seem to go a bit silly for… I happen to have a rare example of a Toy Soldier “Hogue” grip. One of the better versions as well to boot, the rubber coating being extremely durable given the beating its had over the last few years. Forward of this is a Magpul trigger guard, a long time favourite of mine and a nice addition to most M4 base replicas.


The rail is something I have a love/hate relationship with… it’s a Nuprol Bocca 2 9″ Rail which replicates the Daniel Defence Mk18 RIS 2 Rail close enough, the colour although not perfect is far better than the licensed Madbull offering, although if you can get one the VFC or obviously a Genuine DD Rail will pale anything else into insignificance.


On the top of the rail I have an Element LA-5 IR laser designator, this is solely used for night work with NVGs and had to be modded internally to enable it to be zeroed. The LA-5 has been placed as far forward as the rail space allows without overhanging, this limits the splash from the unit whilst on and means that there is nothing in theory that can block the IR laser. The LA-5 is controlled via a remote switch I have wedged in the 1 o’clock position just above the Surefire and under the LA-5 itself, I’m not a fan of rat tail switches but it’s the only logical choice to allow usage of the IR laser on demand.


Just rear of the LA-5 I have mounted the matching repro Knight’s Armament Flip up fore-sight. There are many ways to mount back up irons.. forward of the laser, facing forwards/backwards… but as they are purely there as a last resort, the emphasis is on the laser not the BUIS so they go on once the LA-5 has been put in place. This isn’t my idea… it’s been seen on many real steel rifles and even “no bullshit” shooters like Garand Thumb would agree that BUIS in a slightly less than ideal position is better than no BUIS at all.


Mounted to the left side of the rail is a couple of sections of ladder rail cover, these limit the snag points for the sharp edges of the rail and also prevent the screws holding the bottom section of rail from working loose.

On the right side, remembering that I am left-handed... you’ll find an FMA clone CQD type sling point, this being firmly welded to the rail to the point it’s now a permanent fixture.


Forward of this, an Element SureFire M300 scout light with a flip down IR filter allows me to choose between white and IR light quickly. The scout light is activated via the rear button, I’m not a massive fan of tape switches on lights as a light ND can compromise you to the opposing force, it was after watching a video featuring a certain Chris Costa that I looked at lights as not just a visual aid but also their tactical application.


On the bottom rail section, I simply have a Magpul RVG. It’s a simple lightweight grip that acts as a hand stop and keeps my hand in a consistent position even if I can’t see my hands.

The very front of the replica houses a repro Surefire FH556-216A Flash hider, commonly seen on L119A1/A2s in use with UKSF but also seen (although usually covered with cans) on USSF forces such as MARSOC.

Magazines are the PTS Magpul P-Mags with magpuls on the bottom to aid in pulling out of pouches.


For CQB games or if I’m feeling like going “shock and awe” I’ll stick a tracer unit on, just a standard Marui unit but it looks surprisingly good.

The finishing touches are the wear and tear, this replica has been at my side for 4 years. It’s been everything from an L119A1 to a Mk-12 Mod 1. It’s got more Krylon than metal on it and it’s worn off in the areas you’d expect around the controls and mag well, I’ve helped it along a little but it’s mostly genuine wear. There’s also a QR Armoury code sticker to give it that final touch, kindly donated from a good friend of mine.


As for the sling, a BlueForceGear Padded Vickers Tactical VCAS sling with H&K loops fits nicely into place with the CQD sling mounts and although metal on metal, it doesn’t create a lot of sound. The sling has seen so much use that the label has peeled off, but the sling itself is still holding up fine… as you’d expect from a reputable sling such as this.


To summarise, it’s taken a good many years to find out what works for me, to find and adapt a platform to my needs. Something comfortably familiar but not a carbon clone of every other Mk-18 out there. I have recently migrated onto a gas platform so this is seeing a little less use than before, but I do take it to every game as it’s a solid performer and has yet to let me down. When looking at primary suitable for MilSims you need to look at your own play style, the event itself and most importantly something you actually love the look of.

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