One of my New Year’s resolutions is to reject, at least temporarily, internet hearsay. You know what Abraham Lincoln said about the internet, right? “Four score of lies, myths, exaggerations and urban legends.” That’s a long way of saying lots of folks read something and then pass it on as the gospel truth.
Knowing that I can be a victim of internet “rumorroids” also, I’ve decided to do something about it. When I hear something that sounds like an established claim, but with nothing to back it up, I just might test its validity myself.
One claim, that’s been passed around for years, is that .22 conversions for AR rifles aren’t worth the trouble because they aren’t accurate, rarely function and have been known to cause massive outbreaks of shingles. So to start my 2015 resolutions, I decided to test one of those kits for myself, just to see.
I ordered a 22AR Conversion Bravo kit from CMMG. They make a variety of conversion products ranging from a simple bolt conversion to kits that replace bolt, magazines, bolt assist adapters and charging handles. The Bravo kit is as basic as it gets. It consists of a stainless steel bolt replacement and a single 25-round magazine. If you live in a rights-challenged state, you can get a Bravo kit with a 10-round magazine.
The basic idea of this conversion kit is simple. You only replace the bolt and magazine. The front of the conversion bolt features a “chamber” that’s a replica of a .223 / 5.56mm cartridge, so that fits in your existing chamber and barrel. The .22LR cartridge feeds into the pseudo chamber on the bolt replacement kit and fires the .22LR projectile out of the conversion kit chamber and into your normal barrel. The theory is that a standard .223 barrel is close enough in diameter for things to work out. Make sense?
To find out how this worked, I brought it to the range along with two AR-type rifles: A Smith & Wesson M&P15 VTAC and a Smith & Wesson M&P Optics Ready model. The VTAC has a 1:7 twist barrel and the OR has a 1:8. We’ll talk more about that later.
I’ve had a Ciener .22LR conversion kit (looks exactly like the one pictured but is phosphate coated and the 30 rd. mag is skinny) for many years. It works ok, some brands of ammo don’t eject reliably so I keep a short aluminum rod in the kit to poke them out. Accuracy is fine but of course the .22LR rounds hit low. I’ve found that if you jack the AR sights up to the max the LR hits on target at 50 yds. When .22 rimfire was cheap and plentiful it was fun spraying the target John Wayne style.
I know exactly how it worked. It was’t accurate.