GunCraft .22 WMR AR15
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- Last updated: 01/07/2019
I first met Rob Chapman at the Silverstone Shooting Centre back in November; I was there to check out the improved facilities, including the new air rifle range and he was there to test some of his straightpull AR15s and the semi-auto 22 Winchester Magnum Rimfire (WMR) that he had been developing for several years. I was immediately impressed by both (and their creator come to that) and really loved his authenticlooking ‘M16’ that he built with the newly available Brownells upper and furniture. Rob let me have a go with both and they functioned perfectly. I recently paid a visit to Rob’s premises in West London and he’s got a really neat set-up in a purposebuilt workshop, with all the lathes and milling machines etc. needed to produce his rifles. Security is obviously a priority and his alarm system in itself is very impressive. Once inside, it was clear that this is a very slick operation, with everything in its place and a place for everything!
Rob first started developing his WMR several years ago, as he could see the potential for such a rifle, as it would add an extra dimension to target shoot shooting and practical disciplines, as the calibre flies faster and flatter than the Long Rifle and can easily reach out to 300-yards; it would also allow the rifle to be used for rabbit and fox control. In standard form, firing a 40-grain bullet, at 100-yards the WMR has more than double the energy of a standard 22LR has at the muzzle, so it is clear that it’s a bit of a mini marvel and, due to our sometimes-bizarre UK firearms laws, we can have semi-autos! Long gone are the days of this round only being available with the traditional, 40-grain bullets however and loads with bullets from 30-50 grains are common and they perform very well at various ranges and the more modern bullets are more accurate than those previously used and their construction is better for vermin control.
The stumbling block for Rob was that weren’t any commercially made magazines available; so, he set about designing his own! An awful lot of rather expensive prototyping then took place, but Rob was determined to see the project through. However, the breakthrough came when Black Dog in the US started making suitable 14-round magazines and this kick started the project once again. The Black Dog mags work well but unfortunately there’s no last round hold open facility; it’s a bit of a shame but the fact that Rob could get on with project far outweighed the disadvantages.
Most of the components for such a semi-auto 22 WMR rifle are obviously standard AR15 parts and it would be possible to build any configuration; ‘medium weight’ barrels are sourced from Sassen Engineering in Birmingham, but the bolt would be the component left for Rob to design. The bolt of a standard AR uses a rotating bolt head that is cammed in and out of engagement with the cut-outs in the barrel extension but a 22 WMR cartridge operates at much reduced pressures, so a simpler, blowback bolt can be used. Various 22 LR bolts obviously existed for the conversion kits that can be used to convert 223/5.56mm ARs to fire the cheaper rimfire round, so something similar but heavier was required and Rob set about designing one. Over the years he made several prototypes, with different dimensions etc. and even modified an upper receiver to see exactly what was going on when it moved back and forth. As well as machined steel, Rob has also employed 3D printing to produce prototype components. The finished product looks great and functions perfectly.
Rob’s 22 Magnum ARs look great, with a standard AR upper and lower receiver, made from 7075-T6 alloy and an M4-style butt that is adjustable for length; the pistol grip is the standard ‘A2’ style but customers can always swap it if they want, as the grip is only held on by a single screw up into the lower. The trigger uses standard components, but Rob has his own springs made that are lighter than standard versions but still ensure reliable ignition of the cartridge. ‘Performance’ trigger springs are 40 thou thick and standard ones are 49 thou; Robs are 42 thou and this seems to be the perfect set-up. The high-quality Sassen barrels are 18-inches long with a 1 in 14 twist and are fitted with an ‘A2’ style flash hider, so any ½-inch UNEF moderator or muzzle brake can be fitted if required. The free float forends are hand-filling without being too bulky, with another length of Picatinny rail on the top and others can be fitted to the KeyMod holes on the sides and base to allow bipods etc. to be attached. As the upper receiver has a Picatinny rail machined into it, any optic can be fitted, depending on what the rife is to be used for. Controls are standard AR, with the usual T-handle used for cocking to rifle.
The overall fit and finish is great and I can see a lot of happy customers in the future! These 22WMR ARs are £1650, which I think is great value for something of this quality and a 14-round Black Dog magazine comes with each rifle; spares are a reasonable £29.95. I’ll be putting one of these cracking little rifles to the test soon, so look out for a follow-up article.