Abstract <p>This paper established three simulation models of the typical 5.8 mm small caliber firearm and evaluated the validity of the model. The three models adopted different geometric models and loading methods. Experimental verification is conducted for the numerical models. The muzzle velocity of the bullet, vibration of barrel, posture of the bullet of the experiment and simulation were compared and analyzed. And the accuracy of the models is evaluated. The calculation results of the three models were evaluated which included velocity of bullet, relative swing angle of bullet, simulation calculation time and pressure of barrel inner wall. The results indicated that these three models could be used in different scenarios as required. When only the motion of the bullet in the chamber is studied, the analysis can be carried out using Model no. 1 with simple barrel and load method, which has a shorter computational time. Model no. 2 takes into account the actual effect of propellant gas pressure in the barrel and is suitable for the study of the inner wall of the barrel. Model no. 3 is the closest to the actual gun situation and is suitable for considering the study of gun system. Combined with the calculation time and simulation results, the three models can have different application scenarios.</p>