7 mm Merrill

by
posted on November 10, 2014
** 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. **
ram.jpg

I am pleased to say that the original idea for this wildcat cartridge was mine. Since I am the most un-mechanical male on the planet, the actual development of the cartridge had to be done by Bob Smith and (mostly) Jim Rock of RPM (Rock Pistol Manufacturing). These guys know about mills and lathes and all. We all wanted a moderate velocity handgun cartridge in 7 mm, as that bore size looked to be just the ticket for long-range handgun work. It was the 70s and the heyday of IHMSA (International Handgun Metallic Silhouette Association) matches. Targets were the thick steel cutouts of animals, placed at as much as 200 meters from the firing line. Since the targets were heavy, it took a pretty powerful blow to topple one. That’s particularly true of the 200 meter ram, which weighed 54 pounds. The range mandated an accurate cartridge with a flat trajectory.

It was a blue-collar sport and the founders were sensitive to the economics of shooting, so inexpensive single shot pistols were the order of the day—Contenders and Merrills. In these guns, a rimmed cartridge was clearly superior to all others, so I spent a lot of time pouring over ammunition manuals and loading books. I wanted a rimmed case (for easy extraction) with a medium powder capacity and convertible to 7 mm. There were no super computer programs to do the searching for you in those times.

After no small amount of effort, the lightbulb over my head went blink one night. My base cartridge was the .225 Win. It was based on the venerable .30-30 and designed by Winchester to replace the .220 Swift. Unlike a couple of other 7 mm wildcats, we gave the 7 mm Merrill the same shoulder angle as the 7 mm Rem. Mag. Using medium- to heavy 7 mm bullets in neck-expanded and fire-formed .225 cases, we got power, flat trajectory, accuracy and (barely) bearable recoil. I was happy to be associated with the project.

Latest

001 Ssocom W Cover 01
001 Ssocom W Cover 01

Review: SAR USA SAR9 SOCOM Compact

The SAR9 SOCOM Compact from SAR USA packs popular tactical features into a compact package.

A Jakl In Bullpup Clothing: Palmetto State Armory's Olcan

Palmetto State Armory adapted its piston-driven Jakl rifle design into a bullpup configuration it calls the Olcan.

150,000 NFA Applications Filed On Day 1 After $0 Tax Stamp Becomes Official

Approximately 150,000 NFA enthusiasts filed their paperwork through ATF’s electronic system in just the first 24 hours of 2026, the first day after the $0 tax stamp for most NFA items became official.

Gun Of The Week: Caracal USA CMP9K

Caracal's CMP9K pistol is based on a design originally produced to replace the aging stock of Heckler & Koch MP5s in United Arab Emirates service.

The Armed Citizen® Jan. 9, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Preview: Roundhouse Provisions Ultimate Campout Kit

Founded by Chuck Norris (yes, that Chuck Norris), Roundhouse Provisions is a company that produces emergency foodstuffs designed to be quickly and simply prepared that will stay fresh for years.

Interests



Get the best of American Rifleman delivered to your inbox.