Brownells - Measuring for Front and Back Sights

Published on August 20, 2012
Duration: 3:29

This guide details the process of calculating the correct heights for front and rear firearm sights. It emphasizes establishing measurements from the bore centerline to the top of the barrel at both the front and rear sight locations. The method involves measuring barrel diameters, dividing by two, and then using the chosen rear sight height to calculate the necessary front sight height for proper alignment.

Quick Summary

Calculating firearm sight heights involves understanding the bore line. Measure barrel diameter at sight locations, divide by two for bore-to-barrel-top distance. Add rear sight height to this for overall rear sight height. Subtract front barrel dimension from overall rear sight height to find the required front sight height.

Chapters

  1. 00:00Introduction to Sight Height Calculation
  2. 00:08Understanding the Bore Line
  3. 00:20Measuring for Rear Sight Placement
  4. 01:11Calculating Rear Sight to Barrel Top Dimension
  5. 01:40Selecting and Measuring the Rear Sight
  6. 02:04Determining Overall Rear Sight Height
  7. 02:22Measuring for Front Sight Placement
  8. 02:45Calculating Required Front Sight Height
  9. 02:58Optimal Sight System Combination

Frequently Asked Questions

How do you determine the correct height for a firearm's rear sight?

To determine rear sight height, first measure the barrel diameter at the desired sight location and divide by two to find the distance from the bore centerline to the barrel top. Then, add the physical height of your chosen rear sight to this measurement for the overall rear sight height.

What is the key principle for aligning firearm sights?

The fundamental principle is that a firearm has only one continuous line: the center line of the bore. All sight calculations and alignments are based on ensuring the sights are aligned with this bore line for accurate shooting.

Where should a rear sight typically be placed on a rifle barrel?

A common placement for a rear sight on a rifle barrel is approximately three to five inches from the receiver. This placement is often chosen for aesthetic reasons and provides a good sight radius.

How is the required front sight height calculated?

The required front sight height is calculated by taking the overall rear sight height and subtracting the dimension from the bore centerline to the top of the barrel at the front sight's location. This ensures proper alignment with the bore.

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