My Dad's carbine resurrection

[Gordyf808]

Hi All!
I am new to the forum and am looking for some insight. A C&R guy and not new to old firearms.
My Dad when he passed a few years ago left all the parts to make a M1 carbine less the receiver.
In the interests of sentiment, I have decided to make a rifle out of them.
Have acquired a new Fulton receiver, and on screwing the barrel in hand tight found the witness marks to be off right at 3/16" hand tight. Looks to be shy of 1/8 turn
Any of you out there with more experience than I have any thoughts on whether the barrel will draw up this far without overtorque?.
I have not even tried yet as I am waiting for the tools and do not want to mess this thing up.
Are there fixes to reduce the draw if I need to or is a new barrel in order? This one is serviceable with good shiny bore, albeit not the best finish. I remember firing the rifle as a kid.
I am not looking for a collector, just a workable shooter.

Thanks in advance for any help
Aloha
Gordy

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[shadycon]

Hi and welcome;
When the barrel is screwed onto the reciever they must line up regardless where the lineup marks are. The books say to use parrallel bars to make sure the flats on the barrel and reciever are parrallel. If they are not lined up correctly then the slide will bind up. Hope this helps. GK

[INLAND44]

Hi All!
I am new to the forum and am looking for some insight. A C&R guy and not new to old firearms.
My Dad when he passed a few years ago left all the parts to make a M1 carbine less the receiver.
In the interests of sentiment, I have decided to make a rifle out of them.
Have acquired a new Fulton receiver, and on screwing the barrel in hand tight found the witness marks to be off right at 3/16" hand tight. Looks to be shy of 1/8 turn
Any of you out there with more experience than I have any thoughts on whether the barrel will draw up this far without overtorque?.
I have not even tried yet as I am waiting for the tools and do not want to mess this thing up.
Are there fixes to reduce the draw if I need to or is a new barrel in order? This one is serviceable with good shiny bore, albeit not the best finish. I remember firing the rifle as a kid.
I am not looking for a collector, just a workable shooter.

Thanks in advance for any help
Aloha
Gordy

Actually I would be more concerned that minimum torque would carry the barrel mark past the receiver mark. I don't know what that torque is but I'm sure it's significant for a barrel installation. This is the kind of problem you can run into assembling used parts.

[ChipS]

If I understand your description, when you look at the front of the receiver from the muzzle end of the barrel and turn the barrel into the receiver hand tight you can not turn it far enough so the index marks align and you need to turn the barrel not more than 1/8 of a full revolution (45 degrees of arc) further to get the marks to align. I have mounted about 20 USGI barrels on USGI receivers and in my opinion your barrel/receiver alignment will match up just fine. You should have no trouble turning the barrel the rest of the way (snugging) onto the receiver with the proper equipment (receiver wrench and barrel block) mounted and used correctly. I always use a pair of parallel bars on the barrel and receiver flats, not the index marks, to correctly align the barrel and receiver but that's just me and the index marks usually end up pretty close. Others may have differing opinions.

Ending up with good bolt headspace is another story but that's the crapshoot you face when you try to mate old used barrels with old used receivers. Fortunately, most serviceable bolts headspace pretty good unless the barrel or receiver is just worn out. HTH

Added: I forgot to ask, and maybe none of our business, but but if you fired the carbine as a kid what happened to the original receiver?

[manteo97]

ChipS is right, if you have about 1/8 turn to go after hand tightening, then it should tighten up OK with the receiver wrench/barrel clamp combination. Clocking up with the index marks (assuming Fulton receivers have the index mark) and then checking with parallel bars will ensure proper slide function, and alignment with front sight and rear sight too.

However, headspace is what you need to be concerned with, especially using a non-USGI receiver. Being a new receiver, it is very important to have the headsapce checked after assembly with the bolt you plan on using. Only correct way to check is with GO/ NOGO gauges.

I'd recommend a qualified gunsmith do this work for you, and by qualified, I mean someone who has worked on M1 carbines and done this (many times) before. I have have seen receiver rings cracked, front tangs snapped off, and dovetails broken( tried to remove an adjustable sight in the wrong direction) by licensed gunsmiths, because they were good generalists, but very little experience with M1 carbines.

Hope this helps you out.

[JimF4M1s (Deceased)]

Welcome to the forum. Nice, helpful group here. Guys will chime in with thought and hints. Lots of information in past threads that could be retrieved using the search feature in the task bar above.

I'm guessing not many have changed barrels. You need the correct tools. Barrel block and wrench almost a must. Keeps from marring anything up. Gauges are needed. Most do this once then the tools sit. Maybe someone has a set they can help you out with.

Sarco may have the barrel wrench and block. $50-$80

Go Gauge, the bolt should close completely on this gauge
No Go, the bolt should not close on this gauge
Field Gauge, used when a firearm fails the No Go. The bolt should not close on this gauge.

You can find these in non GI gauges "Forster" for $75-$100 a set.

Enjoy the forum. And we look forward to your input.

[browningautorifle]

I've changed my share of barrels and assembled a few from parts, not all mating marks come together. I spoke of this one other time and was told I was wrong, they (should) match. Well, I've done several that weren't even close...so beware...then use the blocks or how ever you wish to do it.

[ChipS]

As others have noted, headspace is critical. I should have been more specific above and advised that when putting a previously used USGI barrel and used USGI receiver together the headspace usually is OK unless one of the USGI parts is worn out (or monkeyed with). Both of the parts were originally manufactured and assembled separately but to USGI standard specifications. Sorry for my oversight. BUT, you are putting a USGI barrel on a COMMERCIAL receiver so you have no idea what the resulting headspace will be. It is just as bad, if not worse, to have too little headspace (short chamber) than it is to have too much headspace (long chamber).

If you don't already have the receiver wrench, barrel block and headspace gauges they will set you back about $150, so you may want to consider just sending it to a competent gunsmith to do the whole thing, including finish reaming the chamber if necessary. If you have to finish ream the chamber to get proper headspace it could cost you about another $100 to rent the reamer, and I hope you are very patient and mechanically inclined.

Not trying to discourage you but only to make you aware of reality. Good luck.