Building a revolver
Part modifiers are applied independently and may be positive or negative. Read the mode beside every value and evaluate the full combination.
Worked example
The Long Revolver Barrel adds 1.8 accuracy and 4 projectile damage, subtracts 0.4 stability, weighs 0.3, and costs 3 Slag Metal. It is a clear range-and-damage tradeoff rather than a universal upgrade.