Some of the aspects affect others. Here are some of those interactions:
The balance point of the firearm is the front-to-back location at which there is an equal weight both in front of that point and behind it. The further forward that the balance point is located, the more "tip heavy" the firearm feels and the more effort is required to hold up the front end of the firearm (both pistol and rifle).
The barrel does a number of things as the firearm is discharged:
There are some techniques for modifying the barrel of the firearm to change the handling and performance of the firearm.
Grooves along the length of the barrel are carved. Especially for rifle barrels this will reduce the weight of the barrel while maintaining the structural integrity of the barrel.
Slots are drilled in the top of the muzzle end of the barrel. Those slots allow the expanding gas to escape as the bullet gets close to exiting the muzzle. Those gases push down on the tip of the firearm, counter the perceived recoil.
The components of the firearm are designed and built for a specific size and pressure ammunition. Ammunition that is too small will not seat properly when chambered and too large will not chamber.
The capacity of the firearm refers to the number of rounds of ammunition that it holds. For semi-automatic pistols and rifles, this can include one more than the total in the magazine--the round in the chamber--if the firearm is carried in conditions two, one, or zero.
The angles of the handles of the two kinds of pistols are different, based on the differences in styles of shooting during the times in which they were created.
The design of revolver's handle was designed for pistols that are drawn from hip and fired from waist level, with the angle appropriate for firing from that position. If you hold a revolver pointed straight in front of you with a natural wrist position, the barrel will point 20 to 30 degrees too high.
The design of the semi-automatic pistol's handle was designed for pistols that are fired with your arm straight in front of you, with the angle appropriate for firing from that position. If you hold a semi-automatic at your waist level with a natural wrist position, the barrel will point 20 to 30 degrees too low.
Additionally, if you discharge a semi-automatic with your wrist bent like you would a revolver, you will get hit with the slide as the action cycles.
The frame of the firearm can be made of a few different materials.
The different materials each have different characteristics
The firearm will be rated for certain pressure ammunition. Some firearms can only handle standard pressure ammunition; in those firearms high-pressure ammunition can cause a catastrophic failure.
The internal and external mechanisms that must be deactivated in order to discharge the firearm.
The type of trigger governs from what hammer or striker position(s) the firearm can be discharged.
The total weight of the firearm affects how easily it is handled. Especially for people who are less physically fit or who have disabilities.
This is the kick felt as the firearm is discharged. This is especially important for people who lack the grip strength to control the firearm during the discharge.