Saturday, January 23, 2010

.22 Hornet

While it isn't the smallest the .22 Hornet is the smallest common centerfire rifle cartridge. A rimmed, bottleneck cartridge with a SAAMI working pressure of 43K PSI it was developed from the black powder .22 Winchester Centerfire by some famous wildcatters including Col. Townsend Whelen and Captain G. L. Wotkyns. This first commercial centerfire varmint cartridge was adopted in 1930. Remington and Winchester factory loads use 45 grain pointed soft point or hollow point bullets at a muzzle velocity (MV) of 2,690 fps and muzzle energy (ME) of 723 ft. lbs.

The Hornet's caliber has been a confusing issue. The original Whelen/Winchester specification called for a .2233" diameter bullet, the caliber of the rimfire .22 Long Rifle barrels in which the cartridge was developed. Early commercial .22 Hornet rifles were bored to that dimension. However, virtually all subsequent .22 centerfire cartridges including the Hornet were a .224" bore. Modern Hornet's are .224". The SAAMI-spec standard twist rate for the .22 Hornet is 1:16 inches as a result of Col. Whelen's experiments. This is fine in with the Hornet's standard 45-grain or lighter bullets but does not do well with bullets weighing 50 grains or more. Accordingly some makers, such as Kimber and Ruger, used 1:14 twist rates.

Several years ago I was heavily into the Thompson Center Contender, having sold my Colt SP-1 to purchase my first one, and had an urge to get a .22 Hornet. Coincidentally, one came available and I got it. My barrel is a factory 21" and I have a 4X ____ sight mounted. Most all loads including factory loadings will shoot into 2" or less at 100 yards. However, there are some handloads which will do much better.

My loads:
BulletWeightPowderWeightVelocityEnergy
Winchester46 gr.unknownunknown2640 fps712 fpe
Hornady VMAX35 gr.Lil'Gun12 gr._______________
Hornady VMAX40 gr.Lil'Gun12 gr._______________

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