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Guest post by "Zixinus"
Theresa may be examaning whether the weapon's barrel is rifled or not. Likely it is not, considering the comment.

For those who don't know, an unrifled barrel's inside is a smooth pipe. They have the advantage of being more tolerant of what kind of things you shoot out of it. For this reason they still use them in shotguns where you can fire different kind of ammunitions from it (a packet of metal balls of various sizes to a one-piece slug to exotic stuff like flares and grenades). This also makes producing them simpler. Militaries still use them for special situations.
 
Rifled barrels have a spiral pattern on the inside that encourages the bullet to spin and thus become more stable in its flight, thus much more accurate than a smooth bore. They are more difficult to make and the ammunition you fire must be optimized to the barrel's spiral pattern, thus you can't vary to much in the ammunition's design. They require more work than smooth barrels but the increase in accuracy is worth it. Almost all military guns are rifled, from pistols trough rifles to machine guns (and more).