Airgun pressure chamber barrel length and muzzle velocity calculation

Airgun pressure chamber barrel length and muzzle velocity calculation calculator can be used to determine the optimal barrel length for a given muzzle velocity based on gas expansion principles and to calculate the muzzle velocity from the barrel length and pressure chamber specifications.

Input Parameters

Calculation Results

Calculation Formula

Muzzle Velocity (fps) = √(2 × P × V ÷ W)

Where:
P = Initial Pressure (PSI)
V = Chamber Volume (cc)
W = Bullet Weight (grains)

Optimal Barrel Length (inches) = (Muzzle Velocity ÷ 700) × 0.5

Where:
Muzzle Velocity is in fps

Airgun pressure chamber barrel length and muzzle velocity calculation Calculator Usage Guide

Learn how to use the Airgun pressure chamber barrel length and muzzle velocity calculation calculator and its working principles

How to Use This Calculator

  1. Enter the chamber volume of your airgun in cubic centimeters (cc)
  2. Input the initial pressure of your airgun in PSI
  3. If you already have a barrel installed, enter its length in inches
  4. Enter the weight of your projectile in grains
  5. Select the type of powder you're using
  6. Click the "Calculate" button to see the results

Understanding the Results

  • Muzzle Velocity: The calculated exit velocity of your projectile in feet per second (fps)
  • Optimal Barrel Length: The recommended barrel length for your current setup to achieve maximum efficiency
  • Energy at Muzzle: The kinetic energy of your projectile at the point of exit in foot-pounds

Calculator Formula Explained

The calculator uses the following simplified physics formulas:

Muzzle Velocity = √(2 × P × V ÷ W)

Where:

  • P = Initial Pressure in PSI
  • V = Chamber Volume in cc
  • W = Bullet Weight in grains

The optimal barrel length is calculated using the approximation L = (v ÷ 700) × 0.5, where v is the muzzle velocity in fps.

Important Notes

This calculator provides approximate values based on theoretical calculations. Actual performance may vary based on:

  • Specific powder burn characteristics
  • Barrel efficiency and bore diameter
  • Airgun valve characteristics
  • Temperature and atmospheric pressure

For precise results, it's recommended to test fire your airgun and measure actual performance.