My Love of the M1 Carbine

My first exposure to the M1/2 carbine was in Korea in 1960-61, then again in Vietnam 1966-1967. I carried around 20 different weapons during my 22 years in the Army, and the M1/2 Carbine was my overall favorite.

Most of this information is for use with a M1 Carbine in good condition, but most likely should not be done with a Collector Quality Carbine, since it may harm its value.

The .30 caliber M1 Carbine has a lot going for it as a self defense weapon. It is light weight, easy to shoot, simple to operate, and it is reasonably accurate. Ammunition is readily available and is not too expensive to shoot. About $20 to $24 for fifty rounds of FMJ ammo and between $24 and $35 for fifty rounds of HP or SP ammo.

The ballistic performance of the .30 caliber round is rather modest relative to other long guns. The ME at 100 yards is about 600 Ft pounds at 1500 fps. At 100 Yards the 30 Carbine has the energy of the best 357 Magnum loads at the muzzle. Typically ME is approximately 950 FP and roughly 2000 fps MV. Sighted in for 100 yards, zero crossing at 25 and 100 yards the drop at 150 yards is roughly 4" low and about 1/2" high at 50 yards.

I recommend the following books as being very helpful in learning various aspects of the carbine.


1. The M1 Carbine Owner's Guide by Larry Ruth and Scott Duff. (This book has excellent buying, owning, and maintenance information)

2. Department of The Army TM TM9-1276 CAL..30 CARBINES....1953. I have this at the bottom of my main page in pdf format that you can download.

3. U.S. M1 Carbines, Wartime Production 5th edition by Craig Riesch. An essential guide for identification of parts identification and descriptions of the various war time changes that enhanced the M1 Carbine's reliability.

Interesting and highly detailed

4. War Baby, and War Baby Returns by Larry Ruth. Three volume set. The most complete description of the M1 Carbine's history available. Volume III covers post WWII developments and has considerable information about non GI M1 Carbines. Everything that is in vol 1 & 2 is covered in vol 3.

5. The U.S. .30 Caliber Gas Operated Carbines, A Shop Manual. This the most detailed shop manual for the M1 Carbine, 225 pages, that I am aware of. Available at Brownell's or directly from Heritage Gun Books.

During WWII there were an ongoing series of changes incorporated that either aided reliability or permitted more rapid production of the M1 carbine. Original GI parts will fit any of the ten other sub contractors carbines. This was part of the WWII manufacturing requirements for an M1 Carbine: Interchangeability of all parts.

For example an Inland bolt, barrel slide, hammer, sear, and ETC will drop into a Standard Products, Quality Hardware, Winchester Carbine, or any other WWII without modification. The thing to be alert for is after market counterfeit parts. They are not made to the same mil spec standards and can be really poorly made.

At the end of these articles I will list several dealers and eBay sellers that I have had very good luck with.



Many M1 Carbine barrels suffer from muzzle erosion. Worn rifling at the muzzle end is going to be asymmetrical. This will negatively affect accuracy in the same manner that a damaged crown does. The cause for this muzzle erosion is cleaning from the muzzle end under combat conditions.

There is a quick test for muzzle erosion. Use a standard .30 caliber Carbine ball round and insert its bullet into the muzzle end. There should be at least 1/16th of an inch, preferably 1/8" (or more) of the bullet visible when inserted into the barrel. Do not use a .30 caliber M2 round (30-06), since M2 ball round will show an additional 3/16" of bullet relative to a round of carbine ball ammo.

The military salvaged barrels with muzzle erosion by counter boring the muzzle by .05" to .2". This makes a bullet test meaningless. You can tell a counter bored barrel by noting the rifling does not quite reach the muzzle. The two counter bored barrels I've owned shot acceptably but were less accurate than barrels having a non eroded muzzle.

Replacement GI barrels for M1 carbines are still available in excellent to mint condition. Barrels were manufactured by Underwood until about 1949. There was another batch made during Vietnam, that came with the type 3 barrel band and a unmarked front sight. These are very rare.

Changing barrels on a carbine is fairly easy, IF you have a receiver wrench and barrel wrench intended for the M1 carbine. Without these tools it is very easy to damage the Carbine's receiver during removal and re-installation. This job is better left to a gunsmith having the tools and experience working on M1 Carbines.

POLISH the feed ramp on your .30 caliber carbine. Typically there is no problem feeding FMJ. I've read about, and experienced failure to feed, using SP and HP ammunition. The Winchester HP round has a very small HP cavity, however, this can cause feeding problems when there is a rough surface on the feed ramp. Polishing the feed ramps on the carbines that would not feed these HP rounds solved the FTF problem.

A Dremel tool with hard felt spuds and 220 grit up to 400 grit polishing compound will polish without altering the geometry of the feed ramp. DO NOT alter the feed ramp's geometry !! Gentle pressure is all that's needed when using a Dremel-Tool to polish feed ramps. Using narrow strips of sand paper going in the direction of the bullet travel only, will do just fine by starting with 250 grit, then 400, and finishing with metal polish. Using the narrow strip method is a good idea following any Dremel use also to remove and small marks going across the feed ramp.

The gas piston assembly needs to be checked and cleaned. You really do not know how many rounds have been fired in most used carbines. There is a carbon build up that occurs on the piston during 1000's of rounds of firing. The baked on material is very difficult to clean without the use of toxic chemicals that are also air pollutants. IE Carbon Tetrachloride. My recommendation is to replace the piston and piston nut rather than heroic cleaning attempts.

Remember to thoroughly clean the expansion chamber before installing your new piston and piston nut. (make sure the piston nut is the "Late" style). A piston wrench is necessary and they are available cheaply. The gas piston nut must be staked in place!! This can be done without using a lot of impact force. Too much impact force can damage/warp the gas piston housing. The Army TM discusses removal and re-installation of a gas piston. Riesch's book details the changes made for old and new gas piston nuts.

Bolts & Operating Rod (Slide) Assemblies:

These are a critical wear out items. The Carbine's bolt a life expectancy of about 5-6,000 rounds. The components in carbine bolts were gradually up graded to include improved ejector, improved extractor, improved firing pin, and a round bolt body.

1. The later round bolt AKA "M2 bolt" is much preferred over the earlier flat top bolts. The bearing surfaces of the round bolts are larger and provide better support during operation. The rear caming surfaces provide a slightly longer dwell time than the flat bolts.

The bolts rear caming surfaces MUST be in excellent plus condition. NO PEENING. The rear area of the bolt locking lugs are critical for safe operation. Again no peening, cracks or deformation of the bolt lugs. The receiver locking areas must be straight and not overly worn. After sixty odd years it is best to get a new bolt whenever possible. Yes, complete un-issued bolts show up on eBay. Post WWII Underwood bolts are an excellent choice. These post WWII Underwood bolts are not sought by collectors and tend to be more reasonably priced. Underwood bolts are two color. The rear 1/3 of the bolt body was given additional heat treatment. The blue finish is closer to OD finish on the rear of a properly heat treated bolt. There is also a drain hole about mid way on the bottom of the post WWII Underwood bolts.

2. The only safe way to take a bolt apart is to use the G.I. bolt tool unless you have four hands. These tools are available for under $50 ea. With a new bolt disassembly is still recommended to clean out the 50 year old grease in the firing pin channel. The firing pin must be able to slide freely within its channel. Please refer to Riesch's book for pictures of the latest Firing Pins, Ejectors, and extractors and make sure you're using the latest versions. Purchasing a complete underwood bolt is perhaps the easiest way to insure all parts are the latest.
M1 Carbine Bolt Repair

3. There are six types of operating rod assemblies. The only ones I consider meaningful in a reliable shooter are the type V and VI (M2) slides. These two operating rods incorporate a slightly longer dwell time than the series I-IV type operating rods.

At the bottom rear of the slide assembly is a small bearing surface that engages a slot on the right side of the receiver. The minimum width for safe operation is about 0.080" with 0.09x inches as being preferred. These bearing surfaces do wear and need to be measured since a refinished slide assembly can look great, but still be badly worn.

With enough wear the slide assembly can become unattached from the receiver and present a serious problem. I prefer Inland slides since they are typically cheaper than the late Winchester slides. This reflects the larger production of Inland Carbines. Also type V and VI slides are less sought after by collectors. This is particularly true of the VI slides. I've had the best luck fining "as new" type VI slides at a reasonable cost (bearing lug width of 0.095"). The type VI slide is an M2 Carbine part. A type VI slide differs from a type V slide in that it has been modified to accept the trip lever used in a select fire carbine. The type VI slide is a legal part semi auto part. It was incorporated in very late M1 carbines (Inland & Winchester)


There were five basic stocks issued for the M1 Carbine. Two were early non select fire, two later types modified to incorporate select fire components, and the last was the Paratrooper stock. I owned several M1A1 paratrooper carbines. I've had issues with all of the Paratrooper stock due to wobbly lock up when extended. Original paratrooper stocks have tremendous collector's value and can probably be sold for enough for a complete Carbine overhaul or many years supply of ammunition. ($1000 plus for an original Paratrooper stock)

Fitment of the stock and receiver to the Recoil Plate, and proper fitment of the barrel to the stock is very important for accuracy. Here is how the recoil plate, receiver, and stock connect to make a solid good shooting rifle. If you have a few recoil plates, see which one fits to the receiver the best. I also posted the proper fit of the barrel to stock fit.

The above, along with a barrel in good condition, quality ammo, and normal shooting techniques, should get you on target. This takes you to the next item, "Sights".


Early M1 Carbines used a flip rear sight that should be replaced. Be careful in your removal of the flip rear sight, since the flip rear sights can bring $200 or more from a Carbine collector. The adjustable rear sight is rugged, easy to use, and either style (milled or stamped) is fine. The rear sights need to be staked into place on the receiver. (See Army TM) Once the rear sights are set for windage and elevation, they stay set.

Front sights typically do not need any attention. New front sight assemblies, or those included with a new barrel, may need height adjustment. During WWII manufacture the front sights were filed to provide proper elevation during test firing at 100 yards. (raising the point of impact by reducing the height of the front sight post) A front sight with a top that is almost a point has not been filed.

What I typically do is use the 200 yard rear sight setting and adjust the front sight, if needed, for a 100 yard zero. This allows a "Point Blank" aiming out to 150 yards of +1" (50 yards) and -4" (150 yards) One reason for using the 200 yard setting is to get a higher line of sight and avoid front sight blockage by the hand guard. (more about this later)

Here comes a Doc Lee original observation and fix. The sighting groove in the later, and more rugged, hand guards does not provide a symmetrical front sight picture. The right side of the sighting groove is taller than the left side. I sort of noticed this in Vietnam. I'd go to spare parts and sort through hand guards until I found some that gave me a good sight picture. These were the early hand guards. At the time I had no idea about the various production changes. I've made similar changes, including after market vented hand guards, with all my shooters. I noticed the difference in aiming ease when I tried to quickly sight several of my late production Collectors Grade Carbines.

Since self defense and combat both require a quick and accurate sight picture, I believe that you should check your sight picture and determine if the right side asymmetry affects your ability to rapidly gain a decent sight picture.

There is only one scope sight arrangement that I have used that is satisfactory. Forget about the inexpensive bases that only fit in the rear dovetail after removing the rear sight. Redfield makes, or made a one piece mount that utilizes the rear dovetail and a screw that must be drilled and tapped into the top of the breech area with the identifying "US Carbine Caliber .30 M1" (two lines). This mount stays in place and uses standard Redfield rings. Redfield part # 511146.

There is a newer replacement hand guard that accepts Weaver rings used with a Scout Rifle Scope (long eye relief) or Red dot sight. It looks substantial, but I have zero experience with it. (Fulton Armory)


Unfortunately the price of GI magazines, both 15 round and 30 round have gotten rather high. There are some decent 15 and 30 round after market magazines, however, GI magazine is preferred by most. I have found that the Korean made ones are very good. I have a few of the original USGI ones, but use only the Korean ones for shooting.

All original magazines should be disassembled, cleaned and have the spring replaced. 15 Round magazines do not have a last round bolt hold open followers. Sarco currently is selling 30 round rebuild kits with these hold open followers. I strongly recommend a last round bolt hold open versus a last round and an "CLICK" on empty. In the military we'd add a tracer round or two as the last couple of rounds. These tracers do cause fires and are not recommended for civilian use.

30 Round magazines are TOUCHY. There are a LOT of JUNK 30 magazines for sale. There are many aftermarket 30 round magazines that are worthless. As with the 15 round magazines clean and replace the spring. The original 30 round magazines had problems with people loading 30 rounds and letting them sit for a while. A weak spring shows up first on full auto, but it is a problem with semi auto as well. Use Wolf springs on any 30 round magazine you get. They are cheap insurance as is loading 26-28 rounds per magazine. I'm not sure that the 30 followers allow for long term storage of fully loaded magazines. I believe there may be an over compression of the spring. Also sixty years of flexing may have work fatigued the spring metal. The 15 and 30 round magazines that have beeb recently made in Korea, that have a U on the 15 round ones, and UU on the 30 rounders are as good as USGI mags as far as performance, but are made of thinner metal. You can use my link here M1 Carbine Magazines to order some.


To use a 30 round magazine in a 30 caliber carbine the magazine release assembly should be changed to the updated M2 version. There is a small finger on the left end of the magazine release that mates with two protrusions on a 30 round magazine. This provides proper support for the extra weight and lever arm of the 30 round magazine.

Trigger housing parts:

The safety selector was changed from a push button to a lever type during WWII. This was to avoid confusing the magazine release with the safety during combat conditions. I recommend changing to the later safety at the same time you replace the magazine catch assembly.

Inspect the face of the hammer for galling or peening from the rear of the bolt. Replace worn hammers. This is one of the harder jobs in an M1 carbine, since the hammer plunger is under very heavy spring tension. The hammer plunger and spring can present a real challenge when trying to re-assemble. I mount the trigger housing in a soft jawed vise when removing or re-installing the hammer plunger and spring.

Hammer springs were changed fairly early from 22 coils to 26?? coils. Avoid the 22 coil springs. They significantly increase the trigger pull and were replaced for this reason. The only reason for a 22 coil spring is for an early Collector Grade Carbine.

G: Lubrication:

I've been conducting long term testing with Mobile 1 5W-30 and 10W-40. IMCO there is no difference use which grade ever you have on hand. :) I use Mil-Tech Lithium grease for the rear of the bolt, the operating rod channel on the right side and the two barrel rails that the slide mounts to. A drop of oil on the magazine release track and safety assembly is a good idea as lubrication of the trigger housing pins for the hammer and trigger. Remember a "Little Dab Will Do Ya"

H: Spare parts & accessory items:

Remember the WWII M1 Carbine parts were required to be interchangeable between vendors. Inland and Underwood are two safe bets for most small parts.

Spare Parts:

Slide Spring: 2ea
Complete slide assembly (optional) 1 ea
A complete spare bolt, plus
Firing pin 1 ea
Ejector and spring 2 ea
Extractor 2 ea
Extractor Spring and plunger (easy to lose) 2-3 ea
Hammer spring 1 ea
Hammer plunger 1 or 2 ea. (these tend to go flying and hide)
Trigger housing pins 1 of each type (hammer, trigger, and mounting)
Trigger return spring 1 ea
Gas piston and nut 1 ea

Bore Snake is a useful cleaning tool that's easy to use and cleans from the chamber to the muzzle. 1-2 ea.

Single piece coated cleaning rod intended for .30 caliber and your choice of spuds and cleaning agents. I use JB Compound for very dirty bores and a foam spray cleaner for removing copper fouling.

GI Bolt tool 1 ea
GI Gas Piston Wrench 1 each
Barrel block and receiver wrench (optional a good set is $75+)
Front sight removal and installation tool (Optional and necessary
for safely removing and re-installing front sights)


Original sling and oiler arrangement is not necessary for Self defense use. Get a current front carry sling that will allow you to use both hands while still having ready access to your weapon.

Probably not needed:

Muzzle break, GI, only for M2 carbines. These are helpful on full auto fire and totally unnecessary for semi auto fire.

Flash hider is probably not necessary with today's ammunition or for self defense.


110 Gr Surplus Ball ammo has pretty much dried up. There are several companies selling good quality 110 gr fmj ammo for Target shooting.

For small game hunting and home defense, PPU and Monarch are very good. Monarch is actually made for Academy Sports by PPU. The price for there Soft Points is only about $1 over FMJ prices. These are my prefered ammo for my Carbines.

You may have to polish the feed ramp to feed the soft points. Be sure to function check at least a couple mags of any ammo in a carbine that has already proven to function reliably.

The Best Defense Ammo that will feed 100% in the M1 Carbine, is Horady Critical Defense, but it cost about twice the price of the above. I keep a couple magazines loaded with Critical Defense for Home Defense, and several loaded with PPU SP for SHTF, and of course, several loaded with FMJ for the Range.

There are many dealers and eBay and Amazon, but most offer repo parts and accesories

Dealers with web sites: Amherst Armory, FL Fulton Armory, MD U.S. Armory Both of the dealers below have SOME original parts for M1 carbines. Both have a fair number of after market parts as well. Numrich Sarco

Below is my SHTF Page


 History of the M1 Carbine     M1 Carbine Ammo Information   
 M1 Carbine Forum  M1 Carbine on Facebook
 M1 Carbine on Facebook   M1 Carbine Bolt Repair
 TM9-1276 M1 Carbine Manual  Complete M1 Carbine Manual
 Detailed Disassembly with Photos  M1 Carbine Magazines
 M1 Carbine Markings  M1 type Sling on a Carbine
 M1 Carbine Tech Tips  Shooting the Advisor Pistol
 My Carbine Guestbook  Head Space
 Repair the Trigger Housing  Self Defense Hand Guns