Carbine receiver to bbl thread problem - Gun Hub
Gun Hub

Go Back   Gun Hub > Battle Rifles > M1 Carbine

Reply
 
LinkBack Thread Tools Display Modes
Old 01-22-2006, 10:12 AM   #1
Senior Member
 
LOADER's Avatar
 
Join Date: May 2003
Location: Southern Ohio
Posts: 106
Carbine receiver to bbl thread problem

Started another project, this time using a Quality receiver, ser # 1619xxx, and it is the type that uses an op spring housing, which is new to me. I have scrubbed it thoroughly but a barrel does not thread into it although the receiver threads appear undamaged. Ive tried several different bbls, but all refuse to enter more than a 1/2 twist or so. All of these barrels easily screw into a variety of other receivers I have so I am guessing that my older eyes arent showing me a crossed thread in there but I havent really used much force and havent started applying tools to them yet. It doesnt seem like a good idea to "force" this marriage and I dont want any damage to this older receiver, so I defer to the more experienced members of this forum for sound advice......


Time for dumb questions.....

Are the bbl & receiver thread sizes all the same throughout the USGI series ?

What size / tool can I use to "chase" the receiver threads ?

Best source for orig op spring tubes ?



***** Thanks !
LOADER is offline  
Old 01-22-2006, 07:08 PM   #2
Senior Member
 
Join Date: Oct 2004
Location: N.E.Ohio
Posts: 3,218
With the exception os a few very early Winchester barrel receiver combos, ALL USGI receivers and barrels were interchangeable. That was the primary requirement of all carbine parts. If the barrel deosn't fit in the receiver, then there is definately something wrong.
just watch the internet auction sites for the spring tubes. They are easy to find and not expensive.
jimb16 is offline  
Old 01-23-2006, 05:25 PM   #3
Senior Member
 
LOADER's Avatar
 
Join Date: May 2003
Location: Southern Ohio
Posts: 106
o.k, thanks !, I think I will dress the threads better.
LOADER is offline  
 
Old 07-06-2014, 09:47 AM   #4
Junior Member
 
Join Date: Jul 2014
Location: lavalette west virgnia
Posts: 3
help with a m1 carbine kit build

hello I am searching all over and just cant find what, is the exact, thread, 3/4 what .. on the barrel, for the receiver, and to be honest if any one has a good drawing on the receiver, that would be a blessing, instead on me tearing my inland apart and guessing, it would be great to know just how and where all the receiver holes need to be, sizes and depths, I have been searching for two days since I got my receiver casting from Numrich, and actually they look really good very little needs to be done to finish to a complete receiver, and the hardness I will be doing in a synthetic oil and salt, the sin oil wont burn away like normal oil, or I say something I can make up called super quench, that's is mostly a brine solution. I built Aks, AR-15, FAL, Hk, Uzi, and enjoy building them all and found a lot on the internet, on them all. but on this I am stumped, other than calling the C.M.P. where I got my only inland, they might help me.....well if you can help thanks....larry street
larrystreet is offline  
Old 07-07-2014, 07:39 AM   #5
Senior Member
 
Join Date: Dec 2004
Location: Northern Nevada
Posts: 5,678
Quote:
Originally Posted by larrystreet View Post
hello I am searching all over and just cant find what, is the exact, thread, 3/4 what .. on the barrel, for the receiver, and to be honest if any one has a good drawing on the receiver, that would be a blessing, instead on me tearing my inland apart and guessing, it would be great to know just how and where all the receiver holes need to be, sizes and depths, I have been searching for two days since I got my receiver casting from Numrich, and actually they look really good very little needs to be done to finish to a complete receiver, and the hardness I will be doing in a synthetic oil and salt, the sin oil wont burn away like normal oil, or I say something I can make up called super quench, that's is mostly a brine solution. I built Aks, AR-15, FAL, Hk, Uzi, and enjoy building them all and found a lot on the internet, on them all. but on this I am stumped, other than calling the C.M.P. where I got my only inland, they might help me.....well if you can help thanks....larry street
If the threads were cast into the receiver, then that tells me the factory used a specific threading tap to clean up the threads. You need to determine what the threading is from one of your barrels and then go in search of that tap. I'm betting it's going to be a cast iron beech finding one. It would have been better had they just left the barrel channel completely un-threaded, then you could cut the threads on a lathe. It's an ACME thread IIRC. I've never seen a tap for an ACME thread, but I'm a gunsmith, not a machinist; so for all I know they could be common. The way to find out the barrel thread is to determine how many threads per inch, then cross reference that with a lathe threading chart. Or take the barrel to a machine supply store and see if they have a die that will screw onto your barrel, and then just look at the thread pitch on the die.
Kevin Gibson is offline  
Old 07-08-2014, 01:30 PM   #6
Senior Member
 
Join Date: Sep 2005
Posts: 2,163
If Kevin is correct that the threads are Acme, it'd probably be cheaper to buy a different receiver than to buy an Acme tap. Do check with a couple of local places that sell tooling to industry. We might both be wrong about price and somebody has to make the things. You can figure thread pitch by putting a scale (ruler) against the barrel threads and counting threads per inch. Kevins idea of taking the barrel along to use as a thread gauge has merit too.

I was about to suggest checking local machine shops, but leaving the receiver at a shop without an FFL would be a violation of Federal Law. However, they just might have a tap that works and be willing to do it while you wait (take the barrel too), which would be legal. A very good gunsmith/machinist could setup the receiver in a lathe and single point the threads until the barrel screws in.

However, this will probably involve making a threading tool-which also ain't gonna be cheap.

Just thought of: if you've got a barrel with good threads and a scrap bore (or is otherwise unusable) a good machinist can make the threaded shank into a tap good for a couple of uses.

Last edited by William R. Moore; 07-08-2014 at 01:44 PM.
William R. Moore is offline  
Old 07-08-2014, 01:57 PM   #7
Senior Member
 
Join Date: Dec 2004
Location: Northern Nevada
Posts: 5,678
Quote:
Originally Posted by William R. Moore View Post
I was about to suggest checking local machine shops, but leaving the receiver at a shop without an FFL would be a violation of Federal Law. However, they just might have a tap that works and be willing to do it while you wait (take the barrel too), which would be legal. A very good gunsmith/machinist could setup the receiver in a lathe and single point the threads until the barrel screws in.
I'm betting it's not finished enough to be considered a "gun".


Quote:
Originally Posted by William R. Moore View Post
Just thought of: if you've got a barrel with good threads and a scrap bore (or is otherwise unusable) a good machinist can make the threaded shank into a tap good for a couple of uses.
Now that's a slick idea. Pop that thing on the lathe, even out the shank, square the end for the wrench. Then cut flutes with a ball end cutter on the mill at a 30 degree angle to give an under-cut on the cutting side. Heat treat as hard as you can get it, and I'll bet that just may work. There's not a whole lot of barrel thread to work with, but you wouldn't need much anyhow. The tap would have to be made like a bottom tap anyhow. Makes for a very tough cut, but I'll bet that would work.
Kevin Gibson is offline  
Old 07-08-2014, 02:05 PM   #8
Senior Member
 
Join Date: Dec 2004
Location: Northern Nevada
Posts: 5,678
One complication, the chamber. When you cut the threads over the chamber, it may weaken it too much to use as a tap. Tough call, now I'm not so sure it would work...didn't think about that.
Kevin Gibson is offline  
Old 07-09-2014, 02:45 AM   #9
Senior Member
 
Join Date: Sep 2005
Posts: 2,163
Never having seen a naked carbine barrel shank I have no idea how much metal wold be left. Quite a few taps really don't have all that much metal in the flutes anyway. What I had in mind was a 1 flute gun style tap. However, the chamber could always be plugged with a tightly fitted steel piece either shrunk or silver soldered in. I suppose it could be tigged in place, it'd normalize during hardening.

Last night I realized that we both forgot to specifiy that if he buys a tap, it should be a bottoming tap. I think we both assumed he knew that.
William R. Moore is offline  
Old 07-09-2014, 09:01 AM   #10
Senior Member
 
Join Date: Dec 2004
Location: Northern Nevada
Posts: 5,678
Quote:
Originally Posted by William R. Moore View Post
Never having seen a naked carbine barrel shank I have no idea how much metal wold be left. Quite a few taps really don't have all that much metal in the flutes anyway. What I had in mind was a 1 flute gun style tap. However, the chamber could always be plugged with a tightly fitted steel piece either shrunk or silver soldered in. I suppose it could be tigged in place, it'd normalize during hardening.

Last night I realized that we both forgot to specifiy that if he buys a tap, it should be a bottoming tap. I think we both assumed he knew that.
Yeah I did mention that you would want to cut that shank into the style of a bottoming tap, but good point; you'd want to specify that if you bought a tap.
Kevin Gibson is offline  
Old 07-17-2014, 11:47 PM   #11
Senior Member
 
Join Date: Sep 2005
Posts: 2,163
Son of a gun (no pun intended), I did a quick internet search (bored to tears tonight) and found there's two common 3/4 inch Acme threads. 3/4-6 and 3/4-8 at MSG tooling supply. Right hand thread taps in those sizes run about $120 each. That does seem excessively coarse for barrel threads of that diameter.

Common form thread specs for 3/4 inch are 10 and 16 threads per inch. Special fine threads start at 20 tpi and range upward. Taps of those specs are less expensive but not cheap. A long time ago I bought a 3/4-16 bottom tap for a rebarreling project.

Last edited by William R. Moore; 07-17-2014 at 11:49 PM.
William R. Moore is offline  
Reply

  Gun Hub > Battle Rifles > M1 Carbine


Search tags for this page
m1 carbine bareel shank diameter
,
m1 carbine bareel shank dimensions
,

m1 carbine barrel thread size

,

m1 carbine barrel to receiver assembly

,

m1 carbine barreled receiver

,

m1 carbine receiver threads

,
m1 carbine tap for reciever threads
,
what are the thread dimensions on an m1 carbine barrel
,
what is the thread size of a m1 carbine barrel that screws into receiver
Click on a term to search for related topics.

Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Problem with Win springtube receiver nfield4 M1 Carbine 7 11-17-2008 06:13 AM
New SAI receiver, possible problem roadwarrior762 M14 1 03-12-2008 05:50 AM
03 receiver sight problem Subsnypr Rifles 2 02-28-2007 02:28 PM




Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © 2002 - 2017 Gun Hub. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.