Refer to the INI file for a list of settings you can adjust to your needs. Weapons purchased from Ammu-Nation will always grant a full progress bar (a conditional value of 100%) whereas a weapon picked up from the ground will be much more closer to jamming. You may only attempt to unjam your weapon once per second.
This value ranges from 0% to 100% and once it reaches 0%, your weapon will jam, rendering it unusable until the jam is cleared by tapping the E key (or D-Pad Right on a controller). The progress bar (above the mini-map) indicates the condition of your current weapon. Weapons will gradually degrade when firing them, causing them to jam when the progress bar reaches empty. Introducing weapon jamming, a feature designed to make shootouts more challenging, now available for GTA V! It's a shame that most other shooter games lack this feature, until now. Weapon jamming was one of my favorite things from Far Cry 2.