Introduced in 1970 — a good 11 years after Winchester had released the popular .22 WMR — the modern-looking, bottlenecked 5mm RRM arrived loaded with potential. Here was a hot, fast, varmint number capable of propelling a 38-grain .2045" diameter, hollowpoint bullet to 2,100 fps.

It was 150 fps faster than the fastest .22 WMR of the day. With the improved sectional density offered by the 5mm bullet, it was effective out to 150 yards or so on varmints. In fact, in my home state of Arizona, the 5mm RRM was approved for hunting javelina, legally considered a big game animal.

And it was a complete 5mm flop, due in large part to the existing .22 rimfire rifles in which Remington chambered the exciting new cartridge. The Model 591 clip-fed and the Model 592 tubular-fed 5mm rifles were 5 pound, little wands with atrocious triggers.
Those who I knew owned them, loved them and killed everything with them. Yet, Remington chose to discontinue the models and any future chamberings a brief three years after the new cartridge was introduced!

In short, the quality of the rifles did not match the performance and expense of the ammunition.

Remington 5mm was comparatively expensive. In 1974, 50 rounds of 5mm cost $4.20 while .22 WMR was selling for $2.95 and a box of high-speed .22 LR for $1.20. The production of 5mm RRM ammunition lingered a slower death, but the cartridge finally bit the dust in 1981.

Shortly after Hornady surprised the world with its .17 HMR, I asked a high level member of the Remington corporate staff if Remington might consider reintroducing their 5mm. The answer was an unusually vocal, “Never!”

“Dangerous Dave” Cumberland, The Old Western Scrounger, toyed with the idea of underwriting a limited run, noting there were approximately 52,000 Remington 5mm rifles and 30,000 T/C Contender 5mm barrels in circulation just starved for ammunition, but the project never materialized.

What did materialize were various methods of converting the 5mm Remington rifles into centerfires and forming replacement cases from .22 Hornet brass. In fact, Steve Schroeder of Schroeder Bullets in San Diego still sells a complete conversion kit based on a new bolt head plus formed cases, custom 40-grain 5mm bullets and reloading dies to breathe new life back in those old Remingtons.