CMMG AR15 Rifle

The rifle remains as before but the horrible, plastic buffer tube has been replaced by an alloy model. Likewise the half-length, .22 LR ejection port cover and plastic case deflector have been removed and a full-length 223 cover fitted.

The magazines are considerably different from the old, grey AR15-type design, which weren’t all that. The new Evolution design uses a smoked, polymer inner surrounded by a waffle-pattern open cage, CMMG calls it a skin. They are available in 10 and 25-round capacities and in black or green and feature steel feed lips. Compared to the generic Black Dog AR15, .22 units they feel a lot more solid. The trigger is standard AR with a firm, 2-stage pull, not amazing but workable from the box.

Most unusual on a 22 AR (S&W M&P 15-22 excepted) is the full automatic last round hold open facility combined with manual bolt release. Rifles like the SIG 522 and Spikes Tactical rely on the mag follower literally jamming the bolt open. CMMG have designed a drop-in plate that is actuated by the follower and trips the hold open catch, which also allows you to close the bolt by pressing it as you load a full mag. On the first rifle I tested this unit gave variable reliability and caused feed stoppages and frankly the gun worked better without it. On that point the auto hold open is removable and the Evolution mag offers the normal ersatz hold open on the follower.

This example was much better and apart from one initial stoppage where it locked back after the first round with a full mag in the gun it ran reliably for the test period of around 350-rounds. Equally pleasing magazines locked in easily and reliably and fell free at the push of the button.

AT A PUSH
The Evolution mags are solid-sided so no external, pull-down buttons to aid loading, which like the Black Dog makes them a bit hard to fill to capacity. I managed to get 23-rounds in (25-quoted) at a push but I found 20 easier, after a few refills they did ease a little. I ran the gun on CCI sub-sonics, Mini Mag and Remington Golden 22. Subs are always the big test for 22 semis and I had a few initial feed problems, which appeared to be more magazine than energy/ recoil orientated. However after a couple of mags of the HV the Mk 4 MULTI digested the subs easily enough, even locking back after the last round had fired.

The forward assist works too, which is a feature first appearing in the modified M16 A1 centrefire service rifle, which allows you to manually pump the bolt closed if required.

CMMG use a similar system with a sprung plunger that pushes into a polymer block positioned behind the bolt, this has slots cut into its right-hand side for the tip of the plunger to act on. I always thought a forward assist on a 22 LR semi would be useful.

The mechanism works and does allow you to close the bolt against obstructions. However, on most well made 22 rifles of this type fouling build-up causes a short bolt (not fully shut) and no amount of manual closing can sort it as it needs cleaning to do that. But for the occasional hang up it’s there if required. General presentation is good with all components being well finished in a phosphate-like semi matt black.

The telescopic butt is of the Rock River Arms style and shows a reasonable fit on the buffer tube with just a bit of wobble, which is expected. This ain’t no Magpul stock but again is in keeping with the M4 build spec. On that point the forend is retained at the rear by the standard delta ring and at the front by a cap with the foresight being pinned to the barrel in front of it. So if you were thinking of fitting a free-float/4-way forend then a bit of work is involved getting off the A-frame etc.

With the exception of the D-handle, the Mk 4 MULTI is a very good example, of the generic M4 M16 carbine. Looking at CMMG’s website shows they offer a number of versions of this upper in a number of options that includes lightweight barrel, no sights but a gas block base, a free-float/4-way type forend with and without A-frame. Most interesting to me was the 20” Government Profile with front sight and flat top, near identical to the M16 A2, which would be my choice.

Overall a vast improvement in reliability and general presentation from the first CMMG I tested

PRICE:  ’900 including 1x25-round mag and VAT