The M1 Carbine: The Most Prolific American Small Arm of World War Two

The M1 Carbine is one of the most recognizable and long-serving military firearms in the world. Though many consider it to be the anemic kid brother of the legendary M1 Garand, the carbine has its own unique story, operating features, and role. Anyone interested in guns has, at a minimum, seen the M1 Carbine movies, but most don’t know it was the most prolific American rifle of WWII — even more so than the Garand. As the years tick away and the tenure of the M1 Carbine fades into history, fewer people know its story, how it works, and how fun they are to shoot.

M1 Carbine Specs

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• Cartridge: .30 Carbine
• Barrel: 17.75 inches
• Bolt: Two-lug
• Operating System: Short-stroke gas piston
• Capacity: 15- or 30-round detachable box magazines
• Stock: Black walnut, yellow birch
• Trigger: Two-stage, 4.5 to 7  pounds (spec),  4 pounds, 14 ounces (measured on my IBM model) 
• Parkerized finish
• Sights: Protected front blade, rear peep (L-type or adjustable)
• Weight: 5 pounds, 10 ounces (measured with empty magazine, GI web sling, and oiler)
• Price: $1,100 and up

A Brief History of the M1 Carbine

In the years leading up to WWII, America’s military was making changes to address lessons learned in the first world war, and stay relevant on an evolving potential battlefield. The government adopted the M1 Garand in 1936 and, in 1940, ordered the US Army Ordnance Department to come up with a more portable weapon. 

The goal of this new weapon program was to bridge the gap between the Model 1911 pistol in .45 ACP and the M1 Garand. The average infantry soldier carried an M1 rifle, but the military is made up of much more than just riflemen. Supply soldiers, vehicle drivers, NCOs, officers, and any other soldier who didn’t need or want to carry the full-sized M1 battle rifle had limited options aside from the 1911 or the expensive and heavy Thompson submachine gun. The idea was to develop a small, portable weapon that was more accurate and effective than a pistol, and wouldn’t impede the troop’s primary job. A good example of how this played out in the movies is shown in the series The Pacific, where Eugene Sledge and other mortarmen carried carbines.  

According to Schiffer Military’s book The M1 Carbine: Markings, Variants, Ammunition, Accessories, the criteria for this new weapon were to weigh less than 5 pounds, be able to be carried on a sling, and provide effective fire to 300 yards. As for ammunition, neither the .30/06 M1 Garand ammo or the standard-issue .45 ACP were appropriate. For the project, Winchester designed and submitted a new 7.62mm cartridge, the .30 Carbine, based on the rimmed .32 Winchester Auto.

The M1 Carbine As We Know It

Prototypes for this new carbine were tested by the Ordnance Department in 1941, and they included submissions from Springfield (designed by John C. Garand), Auto Ordnance, Savage, H&R, Woodhull, Colt, and Bendix Aviation. 

Winchester’s submission was partly the result of work they had been doing on updated versions of the M1 Garand, namely a short-stroke gas piston developed by David Marshall Williams. Their team famously created a prototype carbine in 13 days, which beat the competition in September, 1941. This would become the M1 Carbine we all recognize. 

In mass production during WWII, M1 Carbines were made in largest numbers by Inland Manufacturing (a division of General Motors) and Winchester, but also by Rock-Ola Music Corporation who made jukeboxes, Standard Products, Quality Hardware, National Postal Meter, Saginaw Steering and Gear, Underwood, and IBM. That’s right, the IBM that would become known for its computers but which started as International Business Machine and made products such as time clocks and hole-punch technology.

A Long History of Service

More M1 Carbines were made during WWII than M1 Garands (approximately 6.1 million vs. 5.4 million) and the carbine’s service generally outlasted that of its larger service companion. Both were primary U.S. service weapons during WWII and the Korean War, and both were issued to Americans in some numbers during the Vietnam War — one of my high school teachers was issued a Garand on his first trip to Vietnam — and the M1 carbine continued to be used in large numbers by South Vietnamese and indigenous troops throughout the conflict. 

The M1 Carbine has lingered as an active combat arm in many parts of the world for decades since its retirement from the U.S. military. A buddy of mine who spent a decade in the 10th Special Forces Group told me that they encountered Taliban soldiers using them in Afghanistan just a few years ago. He also queried some of his SF buddies, who said that though they weren’t actively being used, they’ve seen M1 Carbines in military arms rooms in parts of Africa recently.

How the M1 Carbine Works

In looks and function, the M1 Carbine is indeed a smaller sibling to the M1 Garand. Ironically, the carbine that John C. Garand submitted for the competition was beaten by one that borrowed many elements from his M1 Rifle. For all their similarities though, the two arms have key differences, and in some ways, the carbine is simpler and more versatile. 

Short-Stroke Gas Piston

The most unique feature of the M1 Carbine, especially for its time, was its early adoption of a short-stroke gas piston to drive the semi-automatic action. What this means is that the system uses a short, captured piston that has a compact range of travel. The piston is held in the gas block under the barrel and concealed by the stock. When a shot is fired and the bullet passes the gas port, the gas block directs gas down from the gas port, and against the back of the piston, driving it back towards the action. The piston’s quick impulsive movement knocks the operating slide to the rear, after which the recoil spring drives the operating slide back forward and a new round is chambered.

The M1 Carbine has a bolt, actuator, charging handle, and receiver that are similar and work in the same way as the M1 Garand’s system, but the key difference is that the M1 Garand’s charging or operating handle, operating rod, and long-stroke gas piston are all one piece. Gas from the Garand presses directly against the end of the operating rod to drive the action with one long movement. On the M1 Carbine, the piston is separate, bridging the gap between gas and the operating slide, cycling it with a short, fast movement.

This was the first major use of a short-stroke gas piston system, and it was later adopted in rifles such as the SKS and, in modern day, the piston-driven AR-15 and similar rifles. The most prolific example of a long-stroke piston in modern times is the AK-47.

Magazine and Trigger Group

A feature that set the M1 Carbine up for success was the use of a detachable box magazine. Standard-issue was a 15-round double-stack magazine, but manufacture of 30-round magazines kicked off in 1945. This was a simpler and more versatile design than the Garand’s internal magazine, which was driven by linkages connected to the recoil spring. For how reliable the Garand was, it depended on good timing and a number of small parts that the box magazine design of the M1 Carbine skirted around.

The trigger group of the M1 Carbine is in a solid steel housing. There is some variation between manufacturers, and some are machined out of entirely one piece. Others incorporate folded studs and folded metal trigger guards. The trigger group is connected to the receiver at two points: a winged stud on the top/rear of the trigger group slides into a slot at the rear of the receiver, and the stud at the front is secured with a drift pin. The connection of trigger group and receiver is similar to, and may have inspired that of the Ruger 10/22.

Evolution and Variation of the M1 Carbine

As the M1 Carbine was issued en masse shortly after its conception, the design was tweaked and modified to help it better fill its role as it gained combat experience. Most gun-savvy folks recognize the regular M1 Carbine and the folding-stock M1A1 Carbine that was issued to many paratroopers. Prototypes of the select-fire M2 Carbine were tested in 1944, but the war was over before large numbers of them could be fielded. 

In addition to model variants, many parts and pieces of the M1 Carbine were updated during WWII, and carbines were retrofitted with these during the war. An informative book for any M1 Carbine owner or enthusiast, the Department of the Army Technical Manual for Cal .30 Carbines M1, M1A1, M2, and M3  from 1953 prescribes the protocol for inspecting, repairing, and upgrading every part of the M1 Carbine. It details differences between older and newer parts, and identifies which are acceptable, and which need to be replaced. It’s a step-by-step guide for the depot armorer on everything from updating the sights to repairing a cracked buttstock. 

If you pay attention, you’ll notice that the individual parts and features can vary greatly on vintage M1 Carbines. Carbines that exist as they left the factory are extremely rare and, because manufacturers often used other manufacturers’ parts, many guns never made it out the door with matching parts. For rifles that were issued, nearly all were overhauled and updated at some point. Most are a mish-mash of parts and were upgraded as required. Here are some of those parts.

Safety 

Initially, the M1 Carbine came with a cross-bolt safety just like the one on a Ruger 10/22. These were issued for much of WWII, but they were easy to confuse with the magazine catch button just in front of the safety. When trying to disengage the safety for immediate use, the shooter would sometimes accidentally drop the magazine free — something that I’ve done several times with this style. Because of this, a rotating, switch-style safety was designed. It points down in the “safe” position, and is rotated back towards the trigger into the “fire” position.

Rear Sight

Many M1 Carbines were issued with a simple L-type rear peep sight, which could alternate between two different peephole heights for 150- and 300-yard ranges. The sight was fixed in a dovetail atop the receiver and not adjustable. 

In 1943, a machined, adjustable rear sight was adopted and many carbines were retrofitted with it. The technical manual I listed earlier describes the process of pressing out the old L-type sight, peening the dovetail, pressing in the new adjustable sight, and staking it to prevent movement. This new type of sight had a knob for windage adjustment, a graduated ramp with pre-marked yardage adjustments for elevation, and an adjustable zero reference plate on the rear of the sight base. Later, another adjustable sight was adopted, this time made with stamped metal parts.

My own carbine was retrofitted with one of the machined sights, which I found to be slightly loose. I removed it, cleaned the dovetails, added a bit of thread locker to the dovetail, reinstalled the site, and re-staked it as prescribed in the manual. So far, so good.

Operating Slides

The operating slides of the M1 were altered slightly over the years, and they’re distinguishable by the machining and shapes of the actuator — the part that actuates and moves the bolt. Beginning in 1945, operating slides were made and modified to be used for the full-auto M2 carbine. The technical manual tells the armorer which should be used on M1 and M1A1 Carbines and which were to be reserved for M2 Carbines at the time.

Bolts

The M2 Carbine was developed to use a fully cylindrical bolt, where the M1 and M1A1 originally had a flat-topped bolt. The newer round bolts work in an M1 Carbine, but they’re made to withstand the rigors of full-auto fire in an M2.

Barrel Bands

The M1 Carbine started off with a thin barrel band, which held the stock, barrel, and handguard in place. Eventually this was replaced with a wider barrel band that could be loosened with a cartridge case via a single screw at the bottom. By late 1944, another iteration had been designed that incorporated a slip-over bayonet lug.

Magazine Catches

The Army technical manual describes three different styles of magazine catch, two being acceptable in 1953. The basic M1 carbine used a magazine catch with two studs to support 15-round magazines. The latest design had an additional stud that fit on the side of the magazine and supported a third tab on the heavier 30-round magazines.

Shooting and Maintaining the M1 Carbine

LIke M1 Garands, M1 Carbines and ammunition were once plentiful on the civilian market, and cheap. Lots of shooters grew up with an M1 Carbine in the closet, and it is a wonderful plinker for shooters of any age. The little .30 Carbine cartridge generates minimal recoil, and ammunition is compact. I’ve heard and read accounts of soldiers and Marines complaining about the efficacy of the cartridge, which is essentially a light, glorified pistol round, but the platform’s longevity speaks to its effectiveness in practice.

The .30 carbine typically fires a 110-grain FMJ bullet at about 1,900 fps — not exactly lighting in a bottle. It’s a little baffling as to how it was effective at all, but the platform did seem to be well-liked. I’m sure that at some point my Grandpa — a BAR man that served in both the 101st and 82nd Airborne Divisions from 1944 through the end of the war— eyeballed somebody’s carbine with envy when it came time for a long march. 

I own a 1943 M1 Carbine made by IBM and, for this story, picked up two modern Auto Ordnance reproductions: their M1 and M1A1. I’ve torn them apart countless times and fired more than 2,000 rounds through the trio in the past few months — in Bastogne-like conditions between -10 and 30 degrees. All the carbines are a joy to shoot, but they aren’t exactly precision instruments. I recorded 46 10-shot groups at 50 yards with the three rifles across seven types of ammunition, and the overall average group size was 2.69 inches. My IBM carbine was the most accurate with an average of 2.45-inch 10-shot groups, but the results were quite consistent. For reference, I also fired 10-shot groups with my M1 Garand, which averaged 1.76 inches.

M1 Carbine Ammo

Stocks of GI 110-grain ball M1 Carbine ammo were once plentiful, but that’s no longer the case. Despite production of the little .30 Carbine taking a back seat to more popular rounds during recent ammo shortages, I was able to gather up 7 different types of factory ammo and reload some ammo myself. Here’s what I had:

• Hornady Critical Defense 110-grain FTX ($1.28 per round)
• PPU 110-grain FMJ ($0.72 per round)
• PPU 110-grain Soft Point ($0.76 per round)
• Winchester 110-grain FMJ ($0.94 per round)
• Remington UMC 110-grain FMJ ($1.10 per round)
• Remington Core-Lokt 110-grain ($2.28 per round)
• Freedom Munitions 110-grain FMJ ($0.72 per round)

Reloading for the M1 Carbine

Along with factory ammo, I did a bit of reloading for my M1 Carbines, producing effective plinking ammo. I used a 110-grain FMJ bullet and 14.0 grains of Hodgdon H110 to get close to 1,900 fps and stay below maximum. It plinked just find and functioned well in the guns.

Qualifying with the M1 Carbine

Another informative book for M1 Carbine owners is FM 23-7, U.S. Carbine Caliber .30 M1 and M1A1 Basic Field Manual, which details the courses of fire and qualification scores for servicemen issued the M1 Carbine. After seeing an average of 2- to 3-inch 10-shot groups at 50 yards, I was quite curious about the requirements for a soldier who was issued an M1 Carbine. 

As prescribed in the field manual, a soldier would shoot qualifications at 100 and 200 yards in different positions, incorporating reloads, for a total of 40 shots for record. At 100 yards, they fired at a “Type A” target, and “Type B” target at 200 yards. These were bullseye-style targets marked from 5 points for a bullseye, down to 2 points for being on paper. Scores of 140, 165, and 180 points would qualify the shooter for Marksman, Sharpshooter, and Expert respectively. For shooters using the non-adjustable L-type rear sight, the threshold was 5 points lower for each level. I can attest that the adjustable rear sights shoot more accurately.

What does the 1944 standard for M1 Carbine proficiency mean? I couldn’t find exact specifications on the bullseye size of the Type A and Type B 100- and 200-yard targets, but I would assume that they correspond closely to the modern NRA 100- and 200-yard service rifle targets, which have bullseyes of 6.25 and 13 inches respectively. To qualify as Expert, a shooter had to average better than 4 out of 5 in the bullseye from each distance over 40 shots. Based on the accuracy I saw with my carbines, I’d say it’s challenging but not impossible. 

To feel out how effective my IBM carbine would be at 200 yards, I hung a two-third-sized IPSC steel plate at 200 yards. After a few shots to get my windage and elevation dialed in, I could hit the target easily with every shot. How effective is the .30 Carbine at 200 yards? At that distance, it’s down to about 1,250 fps — so about like a 9mm. 

M1 Carbine vs M2 Carbine: Controllability

Though the M1 Carbine has very little recoil, the diminutive rifle is so light that it does jump around a bit, especially when compared to a refined platform like an AR-15. Rifle design, and how rifles were fired, was different when the M1 Carbine and M1 Garand were designed. Just as the 1911 pistol was developed in a time where pistols were intended to be shot with one hand only, the M1 Carbine wasn’t necessarily built with recoil impulse and control in mind. Still, shot in a modern style, the M1 Carbine can be fired quite quickly and precisely. I’m not sure that the same can be said for the select-fire version, the M2. Fortunately, my friends at a local gun store and shooting range, Alaska Ammo, let me take their M2 for a test drive and I was able to find out for myself.

I was able to compare the three different styles of the carbine, the M1, the M1A1, and the M2 head-to-head. To evaluate precision and controllability under the timer, I decided to run Bill Drills with each — a 6-round rapid fire drill from 7 yards. From previous shooting, I expected the pistol grip of the M1A1 to give it the edge, but after a few iterations, I was matching time and shooting more precisely with my worn-out old IBM. Though fun, and about 30 percent faster, I couldn’t keep the M2 from stringing rounds vertically. That’s great at 7 yards, but at any distance, full-auto fire would be pretty ineffective. 

Maintaining and Lubricating the M1 Carbine

Look to the internet for advice, and you’ll see any number of recommendations for properly lubricating your M1 Carbine, but the field manual FM-27 details it specifically. When in storage, generally all metal parts should be wiped with a light coating of preservative oil, and moving parts and bearing surfaces should be coated with lubricating oil for normal use. Disassemble into major components, but don’t remove the gas piston unless you know what you’re doing, the retaining nut should be staked into place and can come loose if not re-installed properly.

The M1 Garand requires the use of rifle grease, and that is prescribed for certain parts of the M1 Carbine in wet or other unfavorable conditions. This rifle grease, which is likely Lubriplate 130-A that was used for Garands, is to be dabbed with a finger onto the recess in the operating slide/actuator, under the lip of the receiver above the bolt, into locking recesses of the receiver, and on the bolt camming lug on the face of the hammer. 

Most of us don’t have buckets of spare parts to replace ones that wear out, and I’m not taking my carbine into combat, so I’m a bit more liberal with the grease. For recreational shooting, I’ve found that GAA Grease (Grease, Automotive and Artillery), if you can find it, works great for lubricating, and it’s much easier to clean off than Lubriplate. 

Buying Your Own M1 Carbine

There are still lots of vintage M1 Carbines around, and they can satisfy both collectors and folks who want a fun, historic firearm to plink with and ride along in the truck. They are a reasonable self-defense firearm, and there are some options for quality M1 Carbine ammo that fulfill that purpose. You can find carbines at gun shows, the occasional pawn shop, and they’re regularly for sale on sites like Gunbroker. Good vintage carbines are reliable and will last another lifetime, but do some research. Even books like the technical manual listed above can give you great insight into what to look for and how to spot problems.

Modern M1 Carbines

Unlike the M1 Garand, modern iterations of the M1 Carbine are still being made by Auto Ordnance. Not every part is directly interchangeable with GI carbines, but they are pretty true to form. I got both the M1 and M1A1 versions, and both came with nice walnut stocks and handguards (which do fit GI carbines). 

Both models resemble early-model M1 Carbines, but feature an interesting mix of “older” and “newer” style parts. For example, they both feature some older-style parts, like a second-iteration barrel band and push-button safety, two-rivet handguards, and L-type rear sights. But they also have newer-shaped actuators/operating slides and newer-style three-lug magazine catches to use 30-round magazines. 

The Auto Ordnance carbines shot well and were pretty reliable, though they did seem to be finicky about magazines and some ammo types. The feed ramps aren’t quite as deep as on my vintage IBM carbine, which was exceptionally reliable. I think that considering the price of vintage carbines, if you aren’t sure of what you’re getting, and you just want one to bang away with, these modern replicas are a good value and lots of fun.

Auto Ordnance M1 Carbine

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Auto Ordnance M1A1 Carbine

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M1 Carbine Replicas

The downside of the M1 Carbine for a plinker or recreational shooter is that .30 Carbine ammo has gotten expensive and it’s not easy to find right now. An attractive option is the Ruger 10/22 that’s styled after the M1 Carbine, wood handguard and all. I believe that the 10/22 took some inspiration from the M1 anyway, and this will be a reliable, fun plinker that you can pass down to your kids. 

There are some other models of .22 LR M1 carbines that are quite accurate replicas and very cool, but use caution. I was testing one for this story, and blew the thing up. Some sleuthing and consulting led me to discover that the design is capable of firing when not fully in battery (something the .30 Carbine is designed to prevent), and if you get enough build up of wax or fouling, it can prevent a cartridge from chambering fully. Fired out of battery, it will break the gun and maybe you.

Ruger 10/22 M1 Carbine

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If you want an M1 Carbine to plink in the back yard with your kids, Springfield Armory has a really cool M1 Carbine replica BB gun that’s semi-auto and powered by CO2. It’s got a plastic, not walnut, stock, but it’s otherwise an accurate replica and a hell of a lot of fun. The bolt blows back and cycles with each shot, and with the weighted magazine, it doesn’t feel much different than the real thing.

Springfield Armory M1 Carbine BB Gun

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FAQ

Can you legally own an M1 Carbine?

Yes, in most states, you can legally own an M1 carbine.

How much are M1 Carbines going for?

Typically, M1 Carbines are selling for $1,200 to $2,500. Rare collectibles fetch even more.

Is the M1 Carbine still produced?

Yes, Auto Ordnance makes new M1 carbines, though they aren’t always a 100 percent compatible fit with vintage parts.

What is the difference between the M1 Rifle and M1 Carbine?

The M1 Rifle or Garand is chambered in .30/06 Springfield, uses an internal magazine, and runs off a long-stroke gas piston. The M1 Carbine is chambered in the smaller .30 Carbine cartridge, uses a detachable magazine, and utilizes a short-stroke gas piston. 

Final Thoughts on the M1 Carbine

Like the M1 Garand, the M1 Carbine is one of the United States’ most significant historical firearms. For using what we would consider today an effectively useless cartridge, the miniature M1 racked up decades of military service across the globe and in parallel, influenced a generation of shooters who grew up plinking and honing their marksmanship with them. They are a remarkable pleasure to shoot, and if you can get a nice vintage model, you might just feel a spark of connection with its past.