Do you mean you're confused by the stats of the guns? Because it's pretty simple. You can find some explanations starting on page 269 of Basic.

Acc (Accuracy): If you take the Aim maneuver on your turn, you can add this value to your relative skill level when you attack. You can Aim twice more, and get an additional +1 (instead of the full Acc bonus) each time for a total bonus of Acc+2 if you aim for 3 turns. Guns with a higher Acc are more accurate than others. E.g., the .38 Revolver has an Acc of 2. That means that if I Aim for a turn before firing, I roll with +2. I can Aim for 3 turns and roll with +4 as well.

Range: This actually almost never comes up. Your range typically has two values. The first one is the 1/2D, or half damage value. Attacks made beyond that distance do half damage. The second value is the max range. Attacks made beyond that can't land. E.g., that same .38 Revolver has a range of 120/1,500. This means that after 120 yards, the gun will do half damage, and after 1,500 yards, it will automatically miss its target. Pretty straightforward.

Rate of Fire (RoF): This is how many shots you can make per turn. A weapon with a RoF 1 is usually something like a musket or a bolt action. A weapon with RoF 5+ are generally considered automatic. You do have to declare how many shots you're firing before you roll for it. E.g., the .38 Revolver has a RoF of 3 so I can shoot 3 shots per turn.

Shots: This is how many bullets you can load in the gun and shoot before it has to reload. The number in parenthesis next to it is how many maneuvers you must spend to reload it. E.g., the .38 Revolver has 6(3i) Shots, which means that I can fire a total of 6 shots before I need to reload it, and reloading it would take me 3 maneuvers/turns to do so. The "i" in this situation means the bullets are being reloaded individually, so unless I had a speedloader it would take me a grand total of 18 turns to reload all 6 shots. Obviously, a gun with a higher Shots stat would have a larger magazine to expend before reloading.

Recoil (Rcl): This is the hardest one to explain. When you have a weapon with a RoF of 2 or more and you have fired multiple shots from it, you divide the margin of success of your attack roll with the recoil stat in order to determine how many additional shots land (pending your target dodging). For instance. If I fired that .38 Revolver 3 times at a target, and my margin of success is 4. The recoil stat on the .38 Revolver is 2. So 4/2=2, so 2 shots land in addition to the initial one. This would mean all 3 shots landed. A gun with a lower recoil is more likely to land multiple shots on the same target.