Stingers in Bentz Chambers

There's a lot of confusion and misinformation out there concerning the popular CCI Stinger ammunition. What makes it different? The Stinger is a .22 long rifle cartridge that was made for hyper-velocities. Standard velocity for the .22lr is around 1,000 to 1,100 fps (feet-per-second). Sub-sonic is typically under 1,000 fps. High-velocity ammunition is usually over 1,150, but typically 1,250 fps. The Stinger is meant for hyper-velocities around 1,600 fps. Give or take some fps, these are the general velocities for each type.

The Stinger achieves these high velocities in two ways. Firstly, it has a lighter weight bullet. A 31 grain bullet as opposed to other .22lr ammunition that uses a 36-40 grain bullet. Secondly, it has a longer case which is meant to increase the powder capacity of the cartridge.

On the left you'll see a CCI Mini-Mag HP. On the right is the CCI Stinger. You can easily see the difference in the height of the case. The Stinger's longer case is techinically "out of spec", but still manages to work in the vast majority of .22lr chambers - but not all.

.22lr chambers come in three basic flavors:

• Standard
• Bentz
• Match
  

A Ruger 10/22 carbine, one of the most popular .22 rifles ever, uses a standard chamber for autoloaders. This chamber is made loose to in order to be reliable with a very broad spectrum of bullet types, shapes, profiles and different ammunitions that people will use. The Stinger is safe to use with this chamber.

Bentz chambers are a "match" chamber for autoloaders. They are much tighter than the standard chamber and held to strict specifications. This increases accuracy. Most .920" diameter barrels (heavy barrels, bull barrels) for the Ruger 10/22 have this type of chamber. Many barrel makers warn against the use of the CCI Stinger in their barrels because the Stinger case is too long for the chamber. These bentz chambers do not have the built-in slop to make shooting the Stinger safe. There's a little bit of debate over this. Some people claim that they shoot Stingers in their bentz chambers with no ill effects. Others have had slamfires and other issues. The case on the Stinger is long enough where that when chambered in a bentz chamber, the case itself will hit the rifling and jam itself into it, or not allow the entire case to be supported. At best, accuracy will be negatively effected. At worst, you'll get a slam fire or stuck case.

Match chambers, or at least true match chambers, are not used in autoloading rifles. These are reserved for bolt-action rifles due to being too tight for an autoloader to reliably feed from a magazine. I wouldn't use a Stinger in these either.

If you must shoot the CCI Stinger, use a standard barrel - not a match barrel or target barrel. Green Mountain, a maker of affordable, yet very accurate barrels, makes a special Stinger barrel. This barrel is specifically chambered for the Stinger. It also has a slightly different twist rate to better stabilize the lighter/faster bullet. This barrel is known to produce excellent accuracy for the Stinger whose reputation is not one of being a tack-driver. If you've bought a heavy-target barrel, and still want a hyper-velocity cartridge, consider the CCI Velocitor. This round features a 40 grain bullet at an advertised 1,435 fps. One-third more weight than the Stinger, with 200 fps more than high-velocity ammunition. All in a standard length case.