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Posted: 12/22/2002 5:19:08 PM EST
I am wanting to Build an Upper.
I would like to build an A2 Car with a 16" barrel.

Is it cost effective to build it yourself?

What Tools are envolved with the assembly of the upper?

What about torque requirements?

I have the instructions for the lower assembly.
Is there any thing like that for the upper?

If i am forgeting anything please let me know.

Any Help would be appericated.

Batchman
Link Posted: 12/22/2002 7:30:30 PM EST
batchman, Checkout this [url=http://old.ar15.com/books]Link[/url] then download TM 9 1005 319 23. It is about 2.5mb in size, but worth it. Page 153 has the Upper Receiver and Barrel Assembly, Reassembly section. Hope this helps, Jamie
Link Posted: 12/22/2002 9:34:02 PM EST
Unless you know someone you could borrow the tools from You'll need to buy a barrel wrench for aprox $25 and an upper receiver action block to properly hold the upper in a vice for $30-$40. Also want to add at least one headspace guage (field guage) for approx $20. If you knew you were only going to get one then it would be wise to buy one already assembled.
Link Posted: 12/22/2002 10:21:38 PM EST
Originally Posted By Princeton: If you knew you were only going to get one then it would be wise to buy one already assembled.
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Yeah sure. Wait until he gets that one rolling :) AR building is adictive. Once you see how easy it is and the fast turnaround when you DIY it there is no comming back.
Link Posted: 12/23/2002 7:41:35 AM EST
Jamie: Thanks for the download. I will study throughly before it attempt to build my first upper. Princton: There is a fellow that i work with that has most of the tools that one would need to assemble an upper. The only thing that he does not have is a headspace gauge. A few years back he built a few and then quit. During the whole time he never checked the headspace. The reason that i would like to do this. It has to be cheaper to build your own and also the pride in knowing that i did this. Thanks Again everyone Batchman
Link Posted: 12/23/2002 8:37:50 AM EST
I would highly advise using an action block and insert, rather than barrel vise jaws. There is less chance of twisting the barrel in the receiver, and having the front sight offset. When you torque the barrel nut, first lubricate with moly grease... ordinary wheel bearing grease is fine. Torque to 30 ft-lb, back off, torque up a second time, back off. This smooths the threads and allow a truer torque reading. Now, the third time is the charm, torque to 30 (minimum is 31) then continue until the next notch lines up for the gas tube to enter the receiver. You can use a 6" piece of 1/8" dia piano rod as you do this. Stick in thru and wiggle it side to side. When it swings equal distance from side to side, the holes are lined up well enough. This is NOT rocket science. So, whatever torque over 30 needed to get the next notch to line up is OK. It should be less than 80 ft-lbs, but rarely do I see it go over 50 lb-lbs to obtain alignment. Also note that more torque is not better. And don't go excessive on the grease. As far as torque on the nut of a CAR stock, Duh, clean well, apply some Locktite, and tighten by hand with a CAR stock wrench. That is not a critical thing. You can feel when it is tight, and the Locktite will keep it from backing off. And if you got the lower together, the rest of the upper is easy.
Link Posted: 12/23/2002 10:20:26 AM EST
Originally posted by A_Free_Man ------------------------------------------------ I would highly advise using an action block and insert, rather than barrel vise jaws. There is less chance of twisting the barrel in the receiver, and having the front sight offset. ------------------------------------------------ Is this a visual thing? How do you make sure that you do not get the barrel and the receiver cocked from each other? About headspacing. After reading the information that FiFI gave me it seems that you are checking to make sure that there is enough head space. This is done after the barrel is torqued to the proper spec and gas tube hole aligned. If i read it correctly the bolt should not lockup. Is this correct?
Link Posted: 12/23/2002 1:24:00 PM EST
[Last Edit: 12/23/2002 1:24:40 PM EST by Dano523]
You can use a sight bar, which is inserted into the carry handle and has a point that end just short of the front tower. Or, you can WESCSOG and use dental floss down the middle of the handle and continue to the front sight. What you are going for is that the front sight is to be indexed with the center line of the carry handle, or top of the receiver if you are using a flat top.
Link Posted: 12/23/2002 6:49:34 PM EST
Can you buy a parts kit (similar to the lower kits)? I have a barrel, and in the midst of looking for the receiver, but I would hate to order all those little parts separately. [:)]
Link Posted: 12/24/2002 10:57:40 AM EST
Originally Posted By Dano523: Or, you can WESCSOG and use dental floss down the middle of the handle and continue to the front sight. What you are going for is that the front sight is to be indexed with the center line of the carry handle, or top of the receiver if you are using a flat top.
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Slick idea. I will give it a try. Never thought of dental floss. I will be on the lookout for a upper parts kit and barrel and reviever. Thanks for all of your help.
Link Posted: 12/24/2002 11:10:21 AM EST
I've done a couple of uppers, and switched barrels around, ect. and everything said here is all good. The amount of torque involved doesn't really require a vice, or "vice blocks", and I've never used them. You just need a strong, padded, work platform with an overhang. [;)]
Link Posted: 12/31/2002 10:37:58 AM EST
Batchman, it does not matter how much the barrel is torqued, headspace is not affected. The only things that affect headspace are the bolt, and barrel extension and chamber. With new parts, you will not have a problem. You, as the assembler, cannot adjust the headspace. Headspace may be increased by certain machining operations, but if it is excessive, nothing can be done but get new parts. That being said, with new barrels and bolts from reputable suppliers, you will not have a problem. But if you are assembling a rifle from a kit of used parts, you must check headspace. Look at your fired brass just above the case head. Do you see little shiny rings running around the circumference? This is a sign of stretching in that area, and with just a little more wear and tear, case head separation.
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