Meeting Major Power Factor With A 4-Inch Revolver Barrel And Moon Clips

by
posted on April 8, 2020
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
moonclip-1.jpg

From the vault: A reader submitted this question about meeting Major Power Factor (PF) while shooting a revolver with a 4-inch barrel. The principles outlined in the response still apply today. From the July 2006 issue of Shooting Sports USA.

Q. My revolver is loaded with a moon clip and therefore requires a load with a Power Factor of 165. What loads do you suggest to reach 165+ in a 4-inch revolver? Can the round be loaded to longer length than what is specified for autoloaders?

A. While it is true that loads described in manuals were developed for autoloaders, it is not necessarily true that none of those same loads will make Major PF in a revolver.

As a reference, the Speer Reloading Manual #13, cites velocities that were obtained from a 4-inch pistol barrel. Some of these loads exceeded 185 Power Factor.

Through research and experience, it can be seen that there is a very small difference in velocities from the same loads fired in both types of pistols—revolvers and autoloaders. Even if there was some loss in velocity due to the barrel/cylinder gap, many loads would still make the Power Factor. Even though this may be true, it is still recommended that you chronograph your loads in the specific pistol you are using in order to get the exact velocity. The Speer manual offers plenty of options to start with.

The round loaded can certainly be in a longer overall length cartridge, however this may lead to a slightly lower velocity and an outcome that is the opposite of your goal.

Have a question about the shooting sports? Please email us at [email protected].


See more: Why Does Ballistic Coefficient Improve With Heavier Bullets?

Latest

Daisy Bone Collector 1
Daisy Bone Collector 1

Daisy Puts Bone Collector Branding On Its 1999 Lever Action

Daisy’s Bone Collector 1999 Lever Action BB gun brings True Timber camo and Bone Collector branding to a sub-$50 youth trainer.

Connor Daniel Wins Junior Crown at 2026 NSCA U.S. Open

Team Winchester/White Flyer shooter Connor Daniel broke 187 of 200 to win the junior title at the 2026 NSCA U.S. Open in Hudson, Wisconsin.

Jessie Harrison Captures Ladies Open Title at 2026 USPSA Race Gun Nationals

Jessie Harrison topped Ladies Open at the 2026 USPSA Race Gun Nationals, finishing more than 30 points clear of the runner-up.

A New Era Begins: 1996 National Matches

Congress privatized the Civilian Marksmanship Program in 1996 as first-time champions Brian Zins, Tom Whitaker and Web Wright, III, claimed titles at the National Matches.

Remington Adds Three Subsonic Rifle Loads for Suppressor Use

Remington expands its Subsonic Rifle line with 360 Buckhammer, .308 Win. and .45-70 Gov't loads, all now shipping to dealers.

New: Springfield Armory 1911 DS Prodigy 3.5" AOS 9 mm

Springfield Armory’s 1911 DS Prodigy 3.5" AOS pairs a short bull barrel with a full-length grip module for 18+1 capacity, all for less than $1,600.

Interests



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