If you're training with an AR-15 platform rifle, the 5.56mm ammunition is not only expensive, but also hard to come by. So how do you keep up trigger time without the cost? I think .22LR conversion kits are a good solution.

Plinker Arms has recently released a line of complete AR-15 upper receiver kits that convert your 5.56mm to a .22LR. They sent me the short-barreled rifle version with a 12.5-inch barrel, free-float handguards, and threaded flash suppressor.

My initial impressions of the fit and finish were positive. The blowback-operated upper was packed securely alongside one of Plinker's proprietary 35-round magazines, a loading tool the company calls a "load assist," and a handful of rail covers. The upper itself includes the bolt group and is ready to be mated to any AR-15 lower right out of the box. The free-floating 1913 quad rail extended the full barrel length, allowing for mounting real estate, and the threaded flash hider is removable to allow for a variety of aftermarket options or even a suppressor. Really the only thing the upper lacked was a sighting system. Most of us are particular about our sights, so I understand why they didn't include them.

A few days later the Plinker Arms upper was mated to one of my registered lowers (don't forget the NFA rules if you're opting for the SBR version) and I was headed to the range. The upper fit securely to my lower with almost no play between the two. If anything it was a little tight getting the take-down pins to fully engage but I'm sure that'll ease up over time. I added a small amount of lube to the bolt group and loaded up 35 rounds of .22 LR into the magazine. As I see this as a training tool, I tried my best to keep my manipulations the same as with my 5.56mm configuration. I wanted to see if the gun would still function as it was designed with the reconfigured upper. I added a set of Troy flip-up iron sights and adjusted them to a mechanical zero to get started.

The first round down the pipe brought a smile to my face. I then zero'd the upper for 25 yards. This is considerably closer than I would zero a 5.56mm, but I see this Plinker Arms upper serving as more of a CQB training aid anyway. Once zero'd I was able to shoot groups of under 2 inches at the 25-yard line, in part due to the light recoil of the .22LR round but also as a testament to the quality of the Plinker's barrel. The .22LR round isn't known for accuracy so I was pretty impressed with this grouping.

After almost 200 rounds I had experienced zero malfunctions with the Plinker Arms upper and felt I stayed true to my standard 5.56mm training regimen. At a retail price of $499, it is a very economical option for those looking to reduce their ammunition cost without sacrificing valuable training repetitions.

A.J. George is a patrol sergeant with the Scottsdale (Ariz.) Police Department who also serves as the SWAT team’s crisis negotiation supervisor.

BOX:

Plinker Arms .22LR Upper Conversion Kit Specs:

• Compatible with any MIL-SPEC AR-15 lower receiver

• Compatible with most AR-15 upgrades

• Dedicated forged 7075 T6 alloy upper receiver

• Anodized, aluminum Picatinny-style rail system

• Plinker Arms patent-pending magazine, featuring a bolt hold-open on the last round

• 1:16 twist, free-floated barrel with integrated feed ramp

• Military-style Parkerized finish

• Limited lifetime warranty

• Price: $499