More on the North American Arms Mini Revolver
NAA 1-5/8 in. barrel
Mini-Revolver with "boot" grips, .22LR cylinder installed, .22
WinMag cylinder below.
The North American Arms .22 Magnum Mini-Revolver previously tested can also be ordered with a .22 Long Rifle conversion cylinder at the same time, or obtained later on if you so desire, as happened in my case. Actually, I wasn't expecting much performance out of the .22 LR conversion cylinder, for a couple of reasons. A 1-5/8 in. long barrel just isn't a lot to work with. Some studies have suggested that it takes about 2-1/2 inches of rifling to stabilize a bullet--which seems reasonable. Also, there is a necessarily a lot of 'free bore' in a .22 LR cylinder that necessarily must be as long as the .22 Win Mag cylinder it replaces, making it seem that a lot of powder must be combusted with little or no bullet friction. Finally, they may be different bore dimensions: a .22 WinMag uses .224 in. diameter bullets while a .22 Long Rifle often uses .223 in. bullets--though it does vary by manufacturer. So, I wasn't expecting much. But, I was surprised.
All the shooting was done off-hand, rapid fire, from fifteen feet-- an approximation of intimate deep concealment gun use; particularly for a mini-revolver with no rear sight for snag free retrieval. The first surprise was a 1-1/4 in. 5 shot group from CCI Velocitor Ammo-- amazing accuracy from a gun of this type. However, the chronograph confirmed the horrible velocity drop from the stated (but seldom reached) 1435 fps rifle velocity: a five shot string never broke 500 fps, mired in the 450 fps range. Surprised at the dismal velocity, I fired six shots from my Colt Diamondback revolver to compare-- and the CCI Velocitor gave excellent handgun velocity approaching 1200 fps.
Surprisingly, both the CCI "Quick Shok" (32 grain) and Federal "Spitfires" (31 grain) gave 5 shot groups inside 2 inches. Both rounds fared far better on the chronograph, zipping well into the 950-970 fps range, handily doubling the Velocitor ammo velocity.
The all-around winner was the Lapua Speed Ace 40 grain round nose ammo. It chronographed at 887 fps average, and consistently shot 5 shot rapid fire groups inside 1-5/8 inches. This is very good performance; the equal of a goodly number of standard velocity .22 Long Rifle rounds shot from non-vented rifle barrels (i.e., Browning SA-22 with its 19-1/4 in barrel). As a side note, published ballistics for .22 LR often assume 24 inch barrels, and certainly not "vented" ones.
So, all of this was surprising, in a very good way. These ballistics are better than I expected, bettering not only the NAA .22 LR Mini-Revolver 1-5/8 in. barrel numbers (see NAA Arms website), but also besting the NAA 1-1/8 in. barrel .22 Mag numbers, essentially the equal of many NAA 1-5/8 in barrel .22 Mag rounds. All these, with very good accuracy, and a tremendous decrease in noise and muzzle flash. All pleasant things.
I am a renowned master at overlooking the obvious. The "rim" (loading) side of the overly long .22 LR cylinder shows very little powder residue. What is happening here is that the brass quickly obturates and seals upon firing, giving the bullet the benefit of a longer, larger combustion chamber with the larger cylinder-- resulting higher velocities than what was expected. At a bit over six ounces, this is a far more formidable self-defense revolver than you might think.
And, a lot more fun as well.
Contact: Randy Wakeman, 12362 S. Oxford Lane, Plainfield, IL 60585
By phone: (815) 254-2135
Email: randymagic@aol.com
Copyright 2006 by Randy Wakeman. All Rights Reserved.
