Looking for ideas regarding what works (or doesn't). I am thinking of the following: (1) TRIGGER - reduce creep and pull weight. (2) ACTION BEDDING - on the sides of the action. (3) BARREL BEDDING - just behind the barrel band. Care to share experiences/comment?
Accurizing the M1 Carbine
- Thread starter JEC
- Start date
Not a whole hang of a lot you can do with them. A good, tight fit at the recoil plate is important. The barreled action should lock into the recoil plate and hang just out of contact with the stock at the forend. Make sure there is no contact between the barrel and anything else. The third type of barrel band with the bayo lug is best for accuracy. You can tweak the screw a bit to tighten/loosen the band and do some trial shooting with different screw settings as this can make a difference. If you are getting a 2 inch group @ 50 yds you are doing OK.
Thanks for the comments and the link ... The barrel is actually floating and being pulled down by the barrel band, which is why I thought a bit of bedding compound just back of the band would be good to reduce stress. (Apparently that stress is a good thing). I did sand the bottom of the handgaurd to eliminate stress where the plate locks into the action.
I am not a stranger to accurizing bolt guns but this little carbine is ... well, different. I should be able to start reloading within the next week and will start shooting some groups. Next, I will need to figure out to use a peep.
It is not a GI issue, a new AO.
I am not a stranger to accurizing bolt guns but this little carbine is ... well, different. I should be able to start reloading within the next week and will start shooting some groups. Next, I will need to figure out to use a peep.
It is not a GI issue, a new AO.
I have a National Postal Meter with it's original '43 dated barrel that will put 10 rounds into 3" at 100m.
I haven't done anything to it other than feed it ammo it really likes.
I use Vihtavuori N110 powder, Winchester brass, Sierra 2200 or 2205 series FMJ bullets and small rifle match primers.
The ammo makes a huge difference.
I haven't done anything to it other than feed it ammo it really likes.
I use Vihtavuori N110 powder, Winchester brass, Sierra 2200 or 2205 series FMJ bullets and small rifle match primers.
The ammo makes a huge difference.
Well, lots of M1 Carbines which may be original are in sad condition. Many have rusted/worn/pitted bores and gas pistons rusted in place beyond repair. Doesn't seem to matter if they are USGI or one of the commercial makers later on. Corrosive ammo had a lot to do with rusted out barrels.
IMHO, any M1 Carbine that shoots into 3-4 inches at 100 yards is doing what it was intended to do with the ammo available at the time.
At the moment I am installing new barrels from Tradex which finish just slightly over 470mm. Legal but it has to be done right the first, every time. Here's where the problem comes in. I measured the case lengths after pulling the bullets on 11 different cases that were made by 11 different manufacturers. The case lengths measured from 1.280in to 1.298in.
Here's the kicker 30M1 cases are all over the place from below minimum length to over maximum length by a fair bit. Most of these handy little carbines will digest all of these without issues because they have very generous chambers which aren't conducive to really good accuracy. I had a Universal that was made in the early seventies with all GI parts other than the barrel. I don't know who made the barrel but in had a 1-15 twist rate and looked exactly like the micro groove rifling found on Marlin lever actions at the time. It was an honest 2in shooter at 100 yards. I converted it to a non restricted and accuracy was about 3in.
What I learned from that rebarreling and later on a model 5 Winchester was that the chambers have to be generous unless you are hand loading and making sure your cases are trimmed to suit your chamber. I saw one carbine that was short chambered by a few thou that the bolt didn't rotate all the way into battery and often bulged the case at the base. It must have had just enough engagement that it held and didn't have an out of battery KaBoom. I pulled the barrel for the fellow and cut his chamber .004 deeper. It indexed perfectly so nothing else needed to be done. No more bulged brass.
Tight chambers and accuracy go hand in hand.
Another issue with many M1 Carbines, both USGI and after market clones is that the bevel on the chamber isn't cut deep enough and they will only feed ball ammo. A couple of the AO M1 Carbines I've seen have this problem and the owners usually blame jams and misfeeds on poor magazine feeding. Maybe but I would look into the bevel as well. Military chamber bevels are deep. Deeper than what I see on the Auto Ord offerings and some of the other knock offs.
I have also made up a non restricted length barrel for one Carbine that is made by sleeving a rear assembly, including the gas piston over a match grade take off 30 cal barrel from a gun show bucket. The finished barrel is 22in long and the OD is much larger than a regular Carbine barrel. I have shot it without the gas piston hole drilled and it is basically a bolt action. The thing is, it shoots very well. There is a scope mount on this receiver which is removable but screws to the side. Whoever threw it into the scrap box I found it in had broken off a couple of taps and made a mess. That's OK because I can play with it and not worry about ruining anything valuable or collectible.
One thing I have noticed with the front barrel bands is that it doesn't matter if it's one of the typ I, II or III as far as good accuracy goes. The type III is the best but the real pesky kicker is the little hanger clamp utilized to keep everything in line. Likely to protect the op rod. That's why the type III works best. It doesn't seem to clamp tightly to the barrel.
The present rifle I'm working on with a heavy barrel doesn't have the same front band system. I had to modify the stock and handguard by relieving the wood around where the barrel sits. None of the regular bands will fit so they were eliminated completely and an old Mauser band was modified to do the job but only holds the upper guard in place and only utilizes the band spring retainer. It doesn't touch the barrel in any way. This just may be the solution to the accuracy issues with the M1 Carbine.
The model 88 Winchester has a similar issue with the barrel. Different but still in the same area.
IMHO, any M1 Carbine that shoots into 3-4 inches at 100 yards is doing what it was intended to do with the ammo available at the time.
At the moment I am installing new barrels from Tradex which finish just slightly over 470mm. Legal but it has to be done right the first, every time. Here's where the problem comes in. I measured the case lengths after pulling the bullets on 11 different cases that were made by 11 different manufacturers. The case lengths measured from 1.280in to 1.298in.
Here's the kicker 30M1 cases are all over the place from below minimum length to over maximum length by a fair bit. Most of these handy little carbines will digest all of these without issues because they have very generous chambers which aren't conducive to really good accuracy. I had a Universal that was made in the early seventies with all GI parts other than the barrel. I don't know who made the barrel but in had a 1-15 twist rate and looked exactly like the micro groove rifling found on Marlin lever actions at the time. It was an honest 2in shooter at 100 yards. I converted it to a non restricted and accuracy was about 3in.
What I learned from that rebarreling and later on a model 5 Winchester was that the chambers have to be generous unless you are hand loading and making sure your cases are trimmed to suit your chamber. I saw one carbine that was short chambered by a few thou that the bolt didn't rotate all the way into battery and often bulged the case at the base. It must have had just enough engagement that it held and didn't have an out of battery KaBoom. I pulled the barrel for the fellow and cut his chamber .004 deeper. It indexed perfectly so nothing else needed to be done. No more bulged brass.
Tight chambers and accuracy go hand in hand.
Another issue with many M1 Carbines, both USGI and after market clones is that the bevel on the chamber isn't cut deep enough and they will only feed ball ammo. A couple of the AO M1 Carbines I've seen have this problem and the owners usually blame jams and misfeeds on poor magazine feeding. Maybe but I would look into the bevel as well. Military chamber bevels are deep. Deeper than what I see on the Auto Ord offerings and some of the other knock offs.
I have also made up a non restricted length barrel for one Carbine that is made by sleeving a rear assembly, including the gas piston over a match grade take off 30 cal barrel from a gun show bucket. The finished barrel is 22in long and the OD is much larger than a regular Carbine barrel. I have shot it without the gas piston hole drilled and it is basically a bolt action. The thing is, it shoots very well. There is a scope mount on this receiver which is removable but screws to the side. Whoever threw it into the scrap box I found it in had broken off a couple of taps and made a mess. That's OK because I can play with it and not worry about ruining anything valuable or collectible.
One thing I have noticed with the front barrel bands is that it doesn't matter if it's one of the typ I, II or III as far as good accuracy goes. The type III is the best but the real pesky kicker is the little hanger clamp utilized to keep everything in line. Likely to protect the op rod. That's why the type III works best. It doesn't seem to clamp tightly to the barrel.
The present rifle I'm working on with a heavy barrel doesn't have the same front band system. I had to modify the stock and handguard by relieving the wood around where the barrel sits. None of the regular bands will fit so they were eliminated completely and an old Mauser band was modified to do the job but only holds the upper guard in place and only utilizes the band spring retainer. It doesn't touch the barrel in any way. This just may be the solution to the accuracy issues with the M1 Carbine.
The model 88 Winchester has a similar issue with the barrel. Different but still in the same area.
Lots-of-great-info-with-your-post--Thanks..!
fingers284
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I have a '42 inland that with all original USGI parts was a 3" shooter at 50 yrds. I replaced the barrel with one of the Tradex non-restricted barrels a few years ago, it is now an honest moa rifle at 100. A few caveats to that tho... it is 'short-chambered and as Bear states, requires a handloaders touch of shortening the brass 12 thou so "lock-up" is secure, second is that it has a scope mounted on it (some mount I picked up at a gunshow that slides into the regular sight dovetail, no mods and works beautifully) . All my mags are GI issue and don't have the feeding problems Bear talks of with the new barrel however I don't have any hardball projectiles and use Sierra or Hornady 110 gr softpoints (I hunt and have shot deer with the gun).
30 Carbine ammo was never corrosive, it was the first cartridge in wide production that never used corrosive primers.
Fifteen years ago I bought an IAI M-1 Carbine. New made, investment cast, receiver, new make barrel and new made chunky wood stock all other parts original gov't contract. I just couldn't swing the nearly $1000 for a shot out military gun not when a shootable repro was just over $400. My IAI will give a good shot, one better than me, around 3 inch groups at 50 yards. The guys in the club who have GI carbines get about 5 to 6 inch groups at 50 yards. I've read that IAI made the barrels to tighter specs than gov't called for. So if your carb has a shot out barrel and you don't go with a GI one a tighter spec'd barrel might help.
But my father, a Second World War combat veteran, once described the M-1 Carbine as a gun intended to hit an enemy soldier at 100 yards or less, not be a sniper's weapon.
But my father, a Second World War combat veteran, once described the M-1 Carbine as a gun intended to hit an enemy soldier at 100 yards or less, not be a sniper's weapon.
Does anybody know anybody that actually put a bedding block under the barrel just back of the barrel band? It seems to me that if the barrel band snugged the barrel down into the bedding, it would force it to remain centered?
Any experience with how to reduce trigger creep?
Any experience with how to reduce trigger creep?
As long as it wasn't made offshore from what I gather. I have a bin with a dozen or so rusty/pitted beyond use M1 Carbine barrels. I can't see any other reason for the corrosion. I realize that all US made Carbine ammo was non corrosive but to think only US made ammo was used in them ???????????????
Fingers, those barrels are short chambered so that the smith can set headspace by cutting the chamber slightly deeper with a reamer to set headspace. Those first barrels look the same as the recent batch but they were better made. The latest batch is OK but the previous batch indexed without having to take any metal off the shoulder. The new barrels don't leave a whole lot to work with. They are still fine but I would have liked to have seen a couple of more millimeters of length.
I checked out Winchester/Saginaw/Inland/Postal Meter chambers and all varied by a few thou from each other but all were chambered deeper than the Auto Ordnance chambers.
As far as trigger pull, there are a lot of things going on in the Carbine trigger housing assembly. I'd be inclined to experiment with several sears and see what happens.
The Carbine was basically intended to be a pistol replacement so there shouldn't be a high expectation of precision accuracy. My USGI tech manual is packed up for house renos, but it has a diagram which shows the targeting/accuracy standard, which wasn't great.
The Carbine was basically intended to be a pistol replacement so there shouldn't be a high expectation of precision accuracy. My USGI tech manual is packed up for house renos, but it has a diagram which shows the targeting/accuracy standard, which wasn't great.
