I suggest that asking anyone that question is unreliable. That person does not have your gun, you do. You must measure that yourself to be sure. This is easy on airguns because most rifling is pressed into a thin wall barrel tube from the outside. So marking a start spot with say a marker or simple tape then measure one complete revolution from the starting mark. If you have a button rifled thick wall barrel, then you can use a tight fitting cleaning patch on a rod works just as well. Mark start on the rod then push the rod forward one revolution and mark the rod again. Then measure the distance on the rod between marks. Very easy.
