‘Light rifle’ is a term we don’t hear very often these days. We have the “assault rifle,” the battle rifle, and the infantry automatic rifle, but the wee light rifle as a concept doesn’t get discussed much. That’s likely because there is only one really worth mentioning, the M1 Carbine. The M1 Carbine won the light rifle competition in 1942 and went on to serve its country around the world. There hasn’t been much mention of light rifles as a genre ever since, but I think we might be seeing a revitalization of the concept of the light rifle.

What is a Light Rifle?

A light rifle, as epitomized by the M1 Carbine, isn’t a pistol-caliber carbine or an intermediate rifle. It fires a real rifle caliber between your typical pistol cartridge and an intermediate rifle round. The .30 Carbine is a perfect light rifle round and exemplifies the concept. In the modern era, no one is taking advantage of the cool .30 Carbine round except for companies still producing M1 Carbine replicas.

A light rifle should be relatively lightweight and compact, even in an era of modern AR carbines. It’s designed to be light, handy, and easily used in and out of vehicles. Something you can toss over your shoulder and forget about. These guns should be semi-automatic with detachable magazines and modern ammo capacities.

The ‘LC’ in Ruger’s LC Carbine stands for light carbine…right?

Its effective range is about 300 yards max, but it’s probably best used within 200 yards. Typically, we want flat-shooting performance out to 150 yards. In a perfect world without the hated NFA, we wouldn’t be limited to 16-inch barrels either, so for that reason, a light rifle could have a barrel of around 10 inches, but not one longer than 16 inches. Maybe we’re not only talking about light rifles here, but also large pistols…that’s for you to decide.

The Modern Light Rifle Cartridge

With all the above in mind, what exactly does a modern light rifle look like? A lot of the light rifle’s use case relies on the cartridge it fires. In 2024 one of the best light rifle cartridges would arguably be the 5.7x28mm. The .30 Carbine and M1 Carbine as a whole was designed to arm troops who weren’t on the front lines. It was smaller and lighter than an M1 Garand, but offered a lot more punch than a M1911.

In the 1990s, NATO wanted a personal defense weapon, specifically a platform that functioned like the M1 Carbine. It armed noncombat troops with something better than a pistol but lighter than a rifle. The program resulted in the FN P90and HK MP7. The P90 seemed to be the more successful weapon, and the 5.7x28mm cartridge has gained a fair bit of popularity ever since.

The PS90 is certainly a light rifle, and the P90 is a PDW variant.

The 5.7x28mm round is roughly the length of a large pistol round. It’s small enough to fit inside a pistol grip and uses a spitzer-type projectile and a bottlenecked cartridge. From a rifle, the round can reach 200 yards with a reasonably flat trajectory. It also has excellent penetration up close. The little 5.7 bullet won’t be confused for a medium game cartridge, but it’s been effective on coyotes and even small hogs.

The 5.7x28mm cartridge isn’t the only option, though. There’s also 4.6x30mm, although I think only two guns on the civilian market use it: the pricey Tommy Built TP7 and the CMMG FourSix AR. One could argue the 10mm, in certain loads, isn’t far from the .30 Carbine.

The CMMG FourSix is one of the few 4.6mm carbines.

The 10mm round in a 16-inch barrel can get a 180-grain Buffalo Bore round moving at up to 1,600 to 1700 feet per second. That’s not far from the 110-grain .30 Carbine round at 1,990 feet per second. The little 10mm might be this realm’s most common ammo option.

The New Trend

This idea has been bouncing around in my head for quite some time. What spurred me to explore it further was the release of the KelTec SUB2000 in 5.7x28mm and the Ruger LC Carbine in 10mm Auto. Both guns fit the concept of a modern light rifle well. Both are lightweight, compact, and capable of reaching 200 yards or so.

Of course, they aren’t the only examples. There’s the semi-automatic FN PS90 with its bullpup format. There are numerous ARs from CMMG in all sizes and in calibers like 5.7x28mm, 10mm, and the previously mentioned 4.6x30mm. The M1 Carbine could still fill the role as well. I think having a folding stock, or in KelTec’s case, an entire folding gun, makes the gun more adept than light rifles.

The KelTec SUB 2000 in 5.7 is a solid contender for best light rifle due to its folding design.

The purpose of such a gun in the civilian context is simple. It’s lightweight, easy to store, and easy to carry. It offers more range than your typical pistol caliber carbine. The rounds tend to have better penetration and overall ballistics. It could be a camp rifle or truck gun. It would also be a great tool for someone who is recoil-sensitive.

Outside of the 10mm rifles, the 5.7 and 4.6 rounds have near rimfire levels of recoil with centerfire reliability. The .30 Carbine tends to be a fairly soft shooter as well. The 10mm rifles aren’t bad, depending on the configuration. The CMMG Banshee series with their radial delayed blowback systems is very soft-shooting, but anything straight blowback can have 5.56-like recoil.

The 10mm LC Carbine could qualify as a light carbine, but its got a bit more recoil than the other options.

The light rifle concept has little if any military application these days. It seems to be purely a civilian concept.

A Worthwhile Cause?

Like many firearms concepts, the light rifle is held back by cost. The guns and ammo are more expensive, and the concept’s benefits aren’t great enough to warrant the additional cost for most people. Things like the KelTec SUB2000 in 5.7 offer a lower barrier to entry, but the ammo price can still be a hassle.

It might be a silly little idea, but if I can get ahold of a SUB2000 in 5.7x28mm, you can look forward (or not) to me testing the concept and seeing if it holds water…or if I’m just bloviating about something silly.

—Travis Pike

Editor’s Note: This piece first appeared in our companion service Shooting News Weekly