User Panel
User Panel
User Panel
|
Posted: 1/5/2012 8:24:30 AM EDT
[#1]
Apparently, it takes expensive machinery to set headspace.
|
|
|
|
Posted: 1/5/2012 8:25:41 AM EDT
[#2]
Quoted:
Apparently, it takes expensive machinery to set headspace. to do what exactly? Are we taking material away or what? |
|
|
|
Posted: 1/5/2012 8:26:44 AM EDT
[#3]
Quoted:
I know how you check headspace but if you had to alter it, what would you be doing exactly.. Im not trying to change mine or build a rifle it was just a question i thought of last night and figured someone here would know. Lets say we are talking about Ar15s M1A's and M1 garands. Thanks! AR's set head space with the barrel extension. M14-by lapping bolt lugs M1-lapping bolt lugs and you can also ream the chamber as it is not chrome lined. If you have to ask these questions, you really need to polish up your knowledge base and skills before you change head space. 
7.62x51 NATO is 1.63215" The others, I have to open the books for.
|
|
|
|
Posted: 1/5/2012 8:27:54 AM EDT
[#4]
my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber.
|
|
|
|
Posted: 1/5/2012 8:28:31 AM EDT
[#5]
Quoted:
Apparently, it takes expensive machinery to set headspace. M14 and Garand can be lapped by hand with a hand tool and lapping compound. You can use machinists die to make sure you are lapping the lugs uniformly. It's not rocket science, but you need to know what you are doing.
|
|
|
|
Posted: 1/5/2012 8:30:33 AM EDT
[#6]
Quoted:
Quoted:
I know how you check headspace but if you had to alter it, what would you be doing exactly.. Im not trying to change mine or build a rifle it was just a question i thought of last night and figured someone here would know. Lets say we are talking about Ar15s M1A's and M1 garands. Thanks! AR's set head space with the barrel extension. M14-by lapping bolt lugs M1-lapping bolt lugs and you can also ream the chamber as it is not chrome lined. If you have to ask these questions, you really need to polish up your knowledge base and skills before you change head space.
7.62x51 NATO is 1.63215" The others, I have to open the books for.
You missed my comment that i was not attempting this. I know some things should be left to a pro. |
|
|
|
Posted: 1/5/2012 8:31:16 AM EDT
[#7]
Quoted:
7.62x51 NATO is 1.63215" You're going to need a very nice machine to actually achieve results at the 50 millionths level. Though, there is apparently one builder that claims to do so. 
|
|
|
|
Posted: 1/5/2012 8:32:13 AM EDT
[#8]
Quoted:
my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. |
|
|
|
Posted: 1/5/2012 8:33:58 AM EDT
[#9]
Quoted:
Quoted:
7.62x51 NATO is 1.63215" You're going to need a very nice machine to actually achieve results at the 50 millionths level. Though, there is apparently one builder that claims to do so.
That is minimum GO for NATO. All head space has a spec to work within. 50 millionths, not sure that clearance is wise. It certainly is not for a battle rifle. It's very easy to get within 7.62x51 NATO spec on a FAL and M14. I have never built a G3 type rifle, so I cannot comment on it's process. |
|
|
|
Posted: 1/5/2012 8:33:58 AM EDT
[#10]
Quoted: Quoted: Apparently, it takes expensive machinery to set headspace. M14 and Garand can be lapped by hand with a hand tool and lapping compound. You can use machinists die to make sure you are lapping the lugs uniformly. It's not rocket science, but you need to know what you are doing. Eh, what's the worst thing that could happen?  |
|
|
|
Posted: 1/5/2012 8:34:10 AM EDT
[#11]
Quoted:
Quoted:
7.62x51 NATO is 1.63215" You're going to need a very nice machine to actually achieve results at the 50 millionths level. Though, there is apparently one builder that claims to do so.
Fortunately, five hundred-thousandths is probably a lot cheaper. EDIT: Upon further review, I need more coffee. And to think I use math-intensive software for a living...
|
|
|
|
Posted: 1/5/2012 8:34:33 AM EDT
[#12]
Quoted:
Quoted:
Quoted:
Apparently, it takes expensive machinery to set headspace. M14 and Garand can be lapped by hand with a hand tool and lapping compound. You can use machinists die to make sure you are lapping the lugs uniformly. It's not rocket science, but you need to know what you are doing. Eh, what's the worst thing that could happen? Kaboom 
|
|
|
|
Posted: 1/5/2012 8:36:09 AM EDT
[#13]
Quoted:
Apparently, it takes expensive machinery to set headspace. with some of the guns out there one would think your right.... |
|
|
|
Posted: 1/5/2012 8:36:27 AM EDT
[#14]
Quoted:
Quoted:
my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building. |
|
|
|
Posted: 1/5/2012 8:37:56 AM EDT
[#15]
Quoted:
Quoted:
7.62x51 NATO is 1.63215" You're going to need a very nice machine to actually achieve results at the 50 millionths level. Though, there is apparently one builder that claims to do so.
Screw that .... i saw it on tv you can just eyeball it |
|
|
|
Posted: 1/5/2012 8:38:55 AM EDT
[#16]
Quoted: Quoted: Quoted: my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building.  EDIT I am sure they are way more things that are specific per rifle too.
|
|
|
|
Posted: 1/5/2012 8:40:00 AM EDT
[#17]
Quoted:
Quoted:
Quoted:
Quoted:
my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building. EDIT I am sure they are way more things that are specific per rifle too.
 No problemo hermano.
|
|
|
|
Posted: 1/5/2012 8:43:57 AM EDT
[#18]
Quoted:
I know how you check headspace but if you had to alter it, what would you be doing exactly.. Im not trying to change mine or build a rifle it was just a question i thought of last night and figured someone here would know. Lets say we are talking about Ar15s M1A's and M1 garands. Thanks! In general, increasing headspace if it's insufficient is easy, decreasing excess headspace is a bitch. To increase headspace, you simply use a chamber reamer. You go slow, cutting a little at a time, until your headspace gauges indicate proper headspace. To decrease excessive headspace, you can set back the barrel. You remove the barrel, and cut some metal off the back. Rethread and remount the barrel. You should now have insufficient headspace. Use a chamber reamer as described above to reset the headspace. Alternatively, some rifles have interchangeable bolt heads that can adjust the headspace within a fairly wide range. I know some Enfields were issued with replacement bolt heads for this purpose. With AR-15s, if you wanted to set back the barrel, I think you'd cut some material from the barrel extension. I think that's the part that sets the headspace on an AR. On most any other rifle, if the barrel has excessive headspace and the barrel needs to be set back and I don't have the interchangeable bolt head option, I'll just put a new barrel on it. The operation is of equal difficulty, and if a barrel has excessive headspace it's probably well used. If I'm going to suffer removing and remounting a barrel, it's going to be a new one. Sans interchangeable bolts, you need machine tools to decrease head space. Hand tools will pass for increasing it. Also, if you have a 16 inch barrel and need to set your barrel back, you might want to just replace it, as barrel set back does reduce length. |
|
|
|
Posted: 1/5/2012 8:46:06 AM EDT
[#19]
She: not enough headspace for that.
|
|
|
|
Posted: 1/5/2012 8:47:09 AM EDT
[#20]
Quoted:
Quoted:
I know how you check headspace but if you had to alter it, what would you be doing exactly.. Im not trying to change mine or build a rifle it was just a question i thought of last night and figured someone here would know. Lets say we are talking about Ar15s M1A's and M1 garands. Thanks! AR's set head space with the barrel extension. M14-by lapping bolt lugs M1-lapping bolt lugs and you can also ream the chamber as it is not chrome lined. If you have to ask these questions, you really need to polish up your knowledge base and skills before you change head space.
7.62x51 NATO is 1.63215" The others, I have to open the books for.
if headspace isn't too bad/far off and extensions already pinned (pre set from manufacture) but doesn't work with the specific bolt you check with and you've got a good selection of spare AR bolts sometimes you can play musical bolts to find one that's works with that barrel, and sometimes you can't. course if you've bought it from a vendor and you're having issues with headspace, call them up and return it for another one. |
|
|
|
Posted: 1/5/2012 8:49:49 AM EDT
[#21]
Quoted:
Quoted:
Apparently, it takes expensive machinery to set headspace. to do what exactly? Are we taking material away or what? Reducing headspace usually involves setting the barrel back one thread, and re-chambereing. This assuming the gas port, if any, remains in the area where it can function with other components. Some arms, like the SMLE, can replace the bolt head with a larger or smaller one to do the same thing. edit to add: nevermind. |
|
|
|
Posted: 1/5/2012 8:51:24 AM EDT
[#22]
For the AR, you can try new or different bolts if you are having an issue with exessive headspace.
If that doesn't work, a new barrel nut or new barrel will solve it. Go the cheapest and easiest route first of course... |
|
|
|
Posted: 1/5/2012 8:54:02 AM EDT
[#23]
Quoted:
Quoted:
Quoted:
Apparently, it takes expensive machinery to set headspace. to do what exactly? Are we taking material away or what? Reducing headspace usually involves setting the barrel back one thread, and re-chambereing. This assuming the gas port, if any, remains in the area where it can function with other components. Some arms, like the SMLE, can replace the bolt head with a larger or smaller one to do the same thing. This is correct with regards to the No. 4. It is not correct with regards to the SMLE. SMLE bolt heads came in one size only and were stoned to the correct size for a particular rifle. They are, in every sense of the word, hand-fitted to their respective rifle. |
|
|
|
Posted: 1/5/2012 9:00:53 AM EDT
[#24]
Quoted:
Quoted:
Quoted:
my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building. I was not taking it as step by step advice just general discussion.. I am no armoror and would not attempt such a undertaking with out hand holding from a professional.. I dont feel like having a rifle kaboom in my face. |
|
|
|
Posted: 1/5/2012 9:04:01 AM EDT
[#25]
Quoted: If you try to set the barrel back on an AR15 you will end up with the gas port clocked to the wrong position.Quoted: I know how you check headspace but if you had to alter it, what would you be doing exactly.. Im not trying to change mine or build a rifle it was just a question i thought of last night and figured someone here would know. Lets say we are talking about Ar15s M1A's and M1 garands. Thanks! In general, increasing headspace if it's insufficient is easy, decreasing excess headspace is a bitch. To increase headspace, you simply use a chamber reamer. You go slow, cutting a little at a time, until your headspace gauges indicate proper headspace. To decrease excessive headspace, you can set back the barrel. You remove the barrel, and cut some metal off the back. Rethread and remount the barrel. You should now have insufficient headspace. Use a chamber reamer as described above to reset the headspace. Alternatively, some rifles have interchangeable bolt heads that can adjust the headspace within a fairly wide range. I know some Enfields were issued with replacement bolt heads for this purpose. With AR-15s, if you wanted to set back the barrel, I think you'd cut some material from the barrel extension. I think that's the part that sets the headspace on an AR. On most any other rifle, if the barrel has excessive headspace and the barrel needs to be set back and I don't have the interchangeable bolt head option, I'll just put a new barrel on it. The operation is of equal difficulty, and if a barrel has excessive headspace it's probably well used. If I'm going to suffer removing and remounting a barrel, it's going to be a new one. Sans interchangeable bolts, you need machine tools to decrease head space. Hand tools will pass for increasing it. Also, if you have a 16 inch barrel and need to set your barrel back, you might want to just replace it, as barrel set back does reduce length. Barrel ext.'s are mostly the same and are very hard so rarely wear out. Thread tenon length is .620"
|
|
|
|
Posted: 1/5/2012 9:05:09 AM EDT
[#26]
The FAL is a little different in that you use pin gauges to find out what size locking shoulder will work with the specific bolt you have. Then it is just a matter of buying the correct size locking shoulder and installing it, it's pretty easy.
|
|
|
|
Posted: 1/5/2012 9:10:20 AM EDT
[#27]
Quoted: Quoted: Quoted: Quoted: my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building. I was not taking it as step by step advice just general discussion.. I am no armoror and would not attempt such a undertaking with out hand holding from a professional.. I dont feel like having a rifle kaboom in my face. It won't have to be rethreaded most times as if you're correcting headspace you may only have to remove a few thou. If the barrel has a gas port or a front sight, it will have to be set back exactly one thread to ensure the port to sight realigns. The bolt face clearance will also have to be reset. It's not hard to do and doesn't take very long. Headspace isn't really that important either
|
|
|
|
Posted: 1/5/2012 9:15:01 AM EDT
[#28]
|
|
|
|
Posted: 1/5/2012 9:17:10 AM EDT
[#29]
Quoted:
The FAL is a little different in that you use pin gauges to find out what size locking shoulder will work with the specific bolt you have. Then it is just a matter of buying the correct size locking shoulder and installing it, it's pretty easy. Very easy to set correctly, I've built 3 so far. Off topic: How does a gunsmith time a barrel such as the M1 Garand? How do they cut the threads so that it times? The barrel is contoured and milled out so it must time correctly for the splines of the gas cylinder. I have always wondered. |
|
|
|
Posted: 1/5/2012 9:22:05 AM EDT
[#30]
Not sure the Garand, but when rebarreling a FAL if the barrel doesn't time you shave the barrel shoulder until it will correctly.
|
|
|
|
Posted: 1/5/2012 9:24:45 AM EDT
[#31]
Quoted:
Not sure the Garand, but when rebarreling a FAL if the barrel doesn't time you shave the barrel shoulder until it will correctly. That's how I did it on my Galil. |
|
|
|
Posted: 1/5/2012 9:27:53 AM EDT
[#32]
[SonsOfGuns] Just eyeball it [/SonsOfGuns]
|
|
|
|
Posted: 1/5/2012 9:53:28 AM EDT
[#33]
Quoted:
Not sure the Garand, but when rebarreling a FAL if the barrel doesn't time you shave the barrel shoulder until it will correctly. Agreed, but how do they cut the breech end threads so that it even comes close to timing correctly? |
|
|
|
Posted: 1/5/2012 9:59:28 AM EDT
[#34]
Quoted:
Quoted:
Not sure the Garand, but when rebarreling a FAL if the barrel doesn't time you shave the barrel shoulder until it will correctly. Agreed, but how do they cut the breech end threads so that it even comes close to timing correctly? If you mean the manufacturing process, it is just a matter of installing the front sight etc. in the correct place relative to the threads or where the barrel hand times on a receiver. My guess is that all that is factored into the blue print and the barrel is turned, threaded to the correct size and pitch and assembled following them. |
|
|
|
Posted: 1/5/2012 10:33:56 AM EDT
[#35]
Quoted:
Quoted:
Quoted:
7.62x51 NATO is 1.63215" You're going to need a very nice machine to actually achieve results at the 50 millionths level. Though, there is apparently one builder that claims to do so.
Fortunately, five hundred-thousandths is probably a lot cheaper. EDIT: Upon further review, I need more coffee. And to think I use math-intensive software for a living... Lol, doh! |
|
|
|
Posted: 1/5/2012 10:36:54 AM EDT
[#36]
Quoted:
Quoted:
If you try to set the barrel back on an AR15 you will end up with the gas port clocked to the wrong position.Quoted:
I know how you check headspace but if you had to alter it, what would you be doing exactly.. Im not trying to change mine or build a rifle it was just a question i thought of last night and figured someone here would know. Lets say we are talking about Ar15s M1A's and M1 garands. Thanks! In general, increasing headspace if it's insufficient is easy, decreasing excess headspace is a bitch. To increase headspace, you simply use a chamber reamer. You go slow, cutting a little at a time, until your headspace gauges indicate proper headspace. To decrease excessive headspace, you can set back the barrel. You remove the barrel, and cut some metal off the back. Rethread and remount the barrel. You should now have insufficient headspace. Use a chamber reamer as described above to reset the headspace. Alternatively, some rifles have interchangeable bolt heads that can adjust the headspace within a fairly wide range. I know some Enfields were issued with replacement bolt heads for this purpose. With AR-15s, if you wanted to set back the barrel, I think you'd cut some material from the barrel extension. I think that's the part that sets the headspace on an AR. On most any other rifle, if the barrel has excessive headspace and the barrel needs to be set back and I don't have the interchangeable bolt head option, I'll just put a new barrel on it. The operation is of equal difficulty, and if a barrel has excessive headspace it's probably well used. If I'm going to suffer removing and remounting a barrel, it's going to be a new one. Sans interchangeable bolts, you need machine tools to decrease head space. Hand tools will pass for increasing it. Also, if you have a 16 inch barrel and need to set your barrel back, you might want to just replace it, as barrel set back does reduce length. Barrel ext.'s are mostly the same and are very hard so rarely wear out. Thread tenon length is .620"
Hadn't considered that. But changing a barrel on an AR is so easy, there's really no point to trying to set back a shot out barrel on one anyway. |
|
|
|
Posted: 1/5/2012 10:38:55 AM EDT
[#37]
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building. I was not taking it as step by step advice just general discussion.. I am no armoror and would not attempt such a undertaking with out hand holding from a professional.. I dont feel like having a rifle kaboom in my face. It won't have to be rethreaded most times as if you're correcting headspace you may only have to remove a few thou. If the barrel has a gas port or a front sight, it will have to be set back exactly one thread to ensure the port to sight realigns. The bolt face clearance will also have to be reset. It's not hard to do and doesn't take very long. Headspace isn't really that important either I don't know if I'd go quite that far. The range of safe operation on most firearms is relatively large, but there are limits to everything. Enough excess headspace invites case head separations. |
|
|
|
Posted: 1/5/2012 10:48:55 AM EDT
[#38]
Quoted:
I don't know if I'd go quite that far. The range of safe operation on most firearms is relatively large, but there are limits to everything. Enough excess headspace invites case head separations.[/div] Any idea what the range is for 7.62x39? I gotta headspace an RPD soon. |
|
|
|
Posted: 1/5/2012 10:53:15 AM EDT
[#39]
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building. I was not taking it as step by step advice just general discussion.. I am no armoror and would not attempt such a undertaking with out hand holding from a professional.. I dont feel like having a rifle kaboom in my face. It won't have to be rethreaded most times as if you're correcting headspace you may only have to remove a few thou. If the barrel has a gas port or a front sight, it will have to be set back exactly one thread to ensure the port to sight realigns. The bolt face clearance will also have to be reset. It's not hard to do and doesn't take very long. Headspace isn't really that important either I don't know if I'd go quite that far. The range of safe operation on most firearms is relatively large, but there are limits to everything. Enough excess headspace invites case head separations. Pfft.. whats the worst can happen. |
|
|
|
Posted: 1/5/2012 10:58:10 AM EDT
[#40]
Please ignore patriot73. He really doesn't know what he's talking about.
|
|
|
|
Posted: 1/5/2012 11:04:07 AM EDT
[#41]
Quoted: Off topic: How does a gunsmith time a barrel such as the M1 Garand? How do they cut the threads so that it times? The barrel is contoured and milled out so it must time correctly for the splines of the gas cylinder. I have always wondered. I don't know how the Garand works... But generally, you headspace it first, then add the other features. Depending on the model of gun you are working on of course. |
|
|
|
Posted: 1/5/2012 11:11:17 AM EDT
[#42]
Quoted: Quoted: If you try to set the barrel back on an AR15 you will end up with the gas port clocked to the wrong position.Quoted: I know how you check headspace but if you had to alter it, what would you be doing exactly.. Im not trying to change mine or build a rifle it was just a question i thought of last night and figured someone here would know. Lets say we are talking about Ar15s M1A's and M1 garands. Thanks! In general, increasing headspace if it's insufficient is easy, decreasing excess headspace is a bitch. To increase headspace, you simply use a chamber reamer. You go slow, cutting a little at a time, until your headspace gauges indicate proper headspace. To decrease excessive headspace, you can set back the barrel. You remove the barrel, and cut some metal off the back. Rethread and remount the barrel. You should now have insufficient headspace. Use a chamber reamer as described above to reset the headspace. Alternatively, some rifles have interchangeable bolt heads that can adjust the headspace within a fairly wide range. I know some Enfields were issued with replacement bolt heads for this purpose. With AR-15s, if you wanted to set back the barrel, I think you'd cut some material from the barrel extension. I think that's the part that sets the headspace on an AR. On most any other rifle, if the barrel has excessive headspace and the barrel needs to be set back and I don't have the interchangeable bolt head option, I'll just put a new barrel on it. The operation is of equal difficulty, and if a barrel has excessive headspace it's probably well used. If I'm going to suffer removing and remounting a barrel, it's going to be a new one. Sans interchangeable bolts, you need machine tools to decrease head space. Hand tools will pass for increasing it. Also, if you have a 16 inch barrel and need to set your barrel back, you might want to just replace it, as barrel set back does reduce length. Barrel ext.'s are mostly the same and are very hard so rarely wear out. Thread tenon length is .620" How would it clock the Gas port? As far as I remember it is not threaded and has a locating tab to make sure the gas port is correct. |
|
|
|
Posted: 1/5/2012 11:18:12 AM EDT
[#43]
Quoted: How would it clock the Gas port? As far as I remember it is not threaded and has a locating tab to make sure the gas port is correct. You drill it after the barrel is headspaced... Which is why you don't re-headspace AR-15 barrels  |
|
|
|
Posted: 1/5/2012 11:22:47 AM EDT
[#44]
Quoted:
Quoted:
I don't know if I'd go quite that far. The range of safe operation on most firearms is relatively large, but there are limits to everything. Enough excess headspace invites case head separations.[/div] Any idea what the range is for 7.62x39? I gotta headspace an RPD soon. Not off the top of my head. I know that the US military has, at least at times, considered a rifle that was less than 10 thousandths over viable for being issued. 10 thousandths is pretty generous, to say the least. ETA: RPD is obviously not a precision weapon. If I were doing it, I'd probably just get the chamber reamer and ream slowly, checking frequently with my gauges until the go gauge just fit. If you were building a match grade rifle, you might want to use a more precise method. |
|
|
|
Posted: 1/5/2012 11:23:14 AM EDT
[#45]
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building. I was not taking it as step by step advice just general discussion.. I am no armoror and would not attempt such a undertaking with out hand holding from a professional.. I dont feel like having a rifle kaboom in my face. It won't have to be rethreaded most times as if you're correcting headspace you may only have to remove a few thou. If the barrel has a gas port or a front sight, it will have to be set back exactly one thread to ensure the port to sight realigns. The bolt face clearance will also have to be reset. It's not hard to do and doesn't take very long. Headspace isn't really that important either I don't know if I'd go quite that far. The range of safe operation on most firearms is relatively large, but there are limits to everything. Enough excess headspace invites case head separations. Pfft.. whats the worst can happen. You could end up with shards of metal for teeth?
|
|
|
|
Posted: 1/5/2012 11:27:21 AM EDT
[#46]
I must be the only person laughing my ass off at the Sons of guns reference
|
|
|
|
Posted: 1/5/2012 11:40:03 AM EDT
[#47]
Headspacing is probably one of the reasons Savage/Stevens rifles have been the source of many home rifle projects and why there are a lot of aftermarket pre-chambered barrels kits out there.
On those you simply use the gauges, thread the barrel into the receiver to the correct depth, and lock it down with the barrel nut. |
|
|
|
Posted: 1/5/2012 3:07:48 PM EDT
[#48]
Quoted: The indexing pin is on the barrel extn and not the barrelQuoted: How would it clock the Gas port? As far as I remember it is not threaded and has a locating tab to make sure the gas port is correct. You drill it after the barrel is headspaced... Which is why you don't re-headspace AR-15 barrels |
|
|
|
Posted: 1/5/2012 3:14:10 PM EDT
[#49]
Quoted: Quoted: Quoted: Quoted: Quoted: Quoted: my understanding it depends on if it is too big or too small. if it is too big the barrel has to be re threaded and a correct chamber cut. if too small you can just enlarge the chamber. Cool.. thats what i was looking for... Thanks to all. I'd steer away from this advice as it is completely irrelevant in terms of the Garand/M14 design. An M14 has a chrome chamber and if the bolt is too tight (which is fairly common on certain batches of SA, INC. M1A receivers), you use a shorter bolt. The above process describes bolt gun building. I was not taking it as step by step advice just general discussion.. I am no armoror and would not attempt such a undertaking with out hand holding from a professional.. I dont feel like having a rifle kaboom in my face. It won't have to be rethreaded most times as if you're correcting headspace you may only have to remove a few thou. If the barrel has a gas port or a front sight, it will have to be set back exactly one thread to ensure the port to sight realigns. The bolt face clearance will also have to be reset. It's not hard to do and doesn't take very long. Headspace isn't really that important either I don't know if I'd go quite that far. The range of safe operation on most firearms is relatively large, but there are limits to everything. Enough excess headspace invites case head separations. It would have to be excessive for that to happen, and for that you would really need a field gauge, which would be about .010" longer than nogo. If you home load, you will be setting your own headspace with your dies, if headspace has stretched to that point the barrel will probably be shot out anyway
|
|
|
|
Posted: 1/5/2012 8:14:04 PM EDT
[#50]
Quoted:
The indexing pin is on the barrel extn and not the barrel The pin goes clear through the extension into the barrel. |
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
