Do Heavy Bullets Cause Rifle Groups To Widen?

by
posted on May 19, 2019
heavybullet.jpg

A reader submitted a question about heavier bullets in reloads possibly causing rifle groups to widen.

Q: When I’m not on the firing line, the rest of my spare time is spent at the reloading bench and I’ve run across an odd anomaly I hope you can help me with. When I go to heavier match-grade bullets with a slightly improved ballistic coefficient, my rifle’s groups seem to widen. Any idea why?

A: Bullet length could be the culprit. To vary weight in a particular brand and caliber of a bullet, manufacturers wind up shortening or lengthening the projectile’s overall length. If everything else remained constant, and only the bullet weight was altered, your rifle’s rate of rifling could be too slow to stabilize the longer and heavier projectile. Before you abandon the heavier bullet and its improved ballistic coefficient though, try a few different reloading recipes from different manuals. Bullet length is only one of the many possible causes.

Another possibility, although unlikely, is the barrel getting so hot it begins to warp. Or mirage is causing an aiming issue.

Since your goal is most likely maximum accuracy, it would be wise to try a wide variety of different loads. There isn’t much predictability when it comes to knowing which your particular rifle will prefer and thus, shoot better groups.

Finally, some guns just don’t agree with certain loads. With safety in mind, keep experimenting and do your research. Eventually you will find the recipe for what you are looking for.

Please submit your questions to [email protected].

Lead photo: Berger 175-grain .308 OTM bullet.

Latest

Buildingstagespeed 4
Buildingstagespeed 4

Guide To Building Stage Speed

These tips for building stage speed in action shooting will help you rise to the top of the match leaderboard at your next competition.

More Than 6,000 Shooters Experience An Improved Range: 1961 National Matches

A refurbished range greeted the more than 6,000 competitors at the 1961 National Matches, a number which broke attendance records.

Rich Combination Of History & Shooting On Display At Creedmoor 150 Match

A weeklong competition with period and recreated rifles was held in October to recognize the 150th anniversary of the original 1874 Creedmoor International Match.

NRA Announces 2025 National Matches Locations & Schedule

The 2025 NRA National Rifle and Pistol Championships will be held at the Cardinal Shooting Center, Alliance Rifle Club, Oklahoma City Gun Club and Winnequah Gun Club next June and July.

2024 Holiday Gift Guide: Rifles

Five rifles that are excellent presents for competitive shooters this holiday season.

All About The 2024 USPSA Alabama State Championship

The 2024 USPSA Alabama State Championship was held at Cavern Cove Competitive Shooting Range in Marshall County, Ala., May 16-18.

Interests



Get the best of Shooting Sports USA delivered to your inbox.