Most weapons differ in damage, ammo stock, and the following ways:
- Aim assistance. This is a special cone in front of main character where targets can be auto-selected while you just tap Fire button.
- Shooting accuracy. Accuracy decreases if you fire in long bursts (pay attention to the Aim Element on the HUD while its size increases).

As a general rule: the more powerful weapon is, the trickier it can be to handle.