"low caliber" is correct and usable in written English.
It is typically used to describe something of low quality or value. For example, "The performance was of a low caliber, and I did not enjoy it."
Low caliber handguns have virtually no kick-back.
Under the ease of use criterion, most low caliber handguns are easy to use.
This is typical of the arrogant way that this agency and its alarmingly low caliber of personnel conduct themselves in public.
There is no way you can take your organization to the next level with this low caliber of management.
At least one Red Cross official described the earthquake as low caliber, stating it was "unlikely the quake had caused a high number of casualties".
I used the very murky term "assault weapon," which can mean any semi-automatic gun with cosmetic changes and often a low caliber ammunition, confusing it with an "assault rifle," which is a fully automatic gun that is currently banned and has been for years.
It's a relatively small caliber, with low recoil and high accuracy, but still powerful enough to use for hunting small game.
They say they use rubber bullets as well as a low-caliber live bullet that is supposed to be fired at knee level or below.
No other officers reported hearing a bullet being fired — an indication, Mr. Browne said, that it came from a low-caliber weapon or pellet gun.
But defenders say that most AR-15s are chambered for.223 or 5.56 ammunition, low-caliber rounds that are less deadly than those used in many handguns.
Today, the second story of the school was pocked with bullet holes, most of them apparently from low-caliber weapons, and there were a half-dozen other holes in the school's concrete wall.
