223 Rem - 75gr Hornady BTHP with AR-Comp

Published on October 4, 2021
Duration: 33:09

This guide details a method for creating a custom bullet seating stem for .223 Remington 75gr Hornady BTHP bullets, addressing issues with inconsistent seating and bullet marking. The process involves using JB KwikWeld epoxy to form a precise mold of the bullet's ogive within a standard seating stem. This technique, demonstrated by a high-level reloading expert, ensures better bullet alignment and more consistent overall length (OAL) in reloaded ammunition.

Quick Summary

The optimal Overall Length (OAL) for .223 Remington loads using 75gr Hornady BTHP bullets and Alliant AR-Comp powder is 2.254 inches, achieving a 0.59-inch group size. Average velocity for this load is around 2730 FPS. Addressing bullet seating stem fit and minimizing runout are key to achieving such precision.

Chapters

  1. 00:00Introduction and Seating Stem Issues
  2. 01:04Customizing a Seating Stem
  3. 03:52Concentricity and Runout Testing
  4. 09:13Test Methodology and Load Data
  5. 15:40Runout Analysis of Test Batch
  6. 17:23Range Testing and Equipment
  7. 20:05Group Results and Analysis
  8. 26:48Conclusion and Bullet Comparisons

Frequently Asked Questions

What is the optimal Overall Length (OAL) for .223 Remington 75gr Hornady BTHP loads with Alliant AR-Comp powder?

The optimal OAL for the 75gr Hornady BTHP with cannelure using 22.9gr of Alliant AR-Comp powder was found to be 2.254 inches, which produced the best group size of 0.59 inches during testing.

What average velocity can be expected for a .223 Remington load with a 75gr Hornady BTHP bullet and Alliant AR-Comp powder?

A .223 Remington load featuring a 75gr Hornady BTHP bullet and 22.9gr of Alliant AR-Comp powder averaged approximately 2730 FPS during testing with an 18-inch barrel.

How does bullet runout affect accuracy in .223 Remington reloads?

Excessive bullet runout, such as 5 thousandths, can significantly impact accuracy by causing flyers in groups. Measuring and minimizing runout, especially with precise loads, is crucial for consistent performance.

What is a common reloading challenge when seating 75gr Hornady BTHP bullets?

A common challenge is finding a seating stem that perfectly matches the bullet's ogive profile, leading to inconsistent seating depth, bullet marking, and increased runout. Customizing a seating stem with epoxy can resolve this.

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