Feeding
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The 22 CB Long uses a 29 grain bullet that the .22 Short uses. The .22 LR uses a heavier bullet, usually about 40 grains.
Usually, rifles are designed for a specific cartridge. It may be that the CBs are a bit shorter in the magazine, or being a bit shorter, enter the chamber at a different angle when feeding. The older Mossberg rifles had a magazine that you could adjust to compensate for the length of the cartridges, thus putting the nose of the cartridge in the proper position to feed into the chamber.
Some tube type rifles ( like the Remington 572 pump ) are marked for the Short, Long, and Long rifle, and will digest most of them. However, there are tube type rifles that are specifically made for the .22 LR only.
Even bullet shapes have a difference in the way cartridges feed into a chamber. A rifle that feeds one type or brand of ammo often will not feed another type or brand the same. Some rifles will not feed and chamber certain brands of hollow point .22s.
You might try a different brand of CB longs and see what they do.
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