advice for installing barrel assembly?

[technique]

don't forget to use and Anti seize when installing a barrel....you will thank me later.

I have to agree with Technical Ted on the torquing method.

[technique]

and by the way....where the heck are all you "get the right tool" guys when there are 10 n00bs in one thread talking about a LPK install with channel locks.....jeez people, expect a PM with a link to any improper gunsmithing threads from me to you from now on.


TAG

[Blacktail 8541]

If you are close to the Oroville area, you can come by and use my vise and action block and what ever else tools you need. If you need any help I will be there to advise.

[CHS]

and by the way....where the heck are all you "get the right tool" guys when there are 10 n00bs in one thread talking about a LPK install with channel locks.....jeez people, expect a PM with a link to any improper gunsmithing threads from me to you from now on.

I'll defend this one.

First off, there are only 2 tools that you really need in order to install an LPK, and that's a 5/32" punch and a 1/8" punch. Yes, you can install those with a pair of channel locks.

All the other parts of a LPK pretty much go right in with your hands very easily.

Also, installing stuff wrong in the lower can't ever lead to a catastrophic failure of the weapon[*]. Doing stuff wrong in the upper, however....



[*] = I don't consider doubling or going full-auto to be a catastrophic failure (eg: installing the trigger components wrong)

[dchang0]

Out of curiosity, what kinds of catastrophic failure could occur with an improperly mated barrel to receiver?

[freakshow10mm]

I'll defend this one.

First off, there are only 2 tools that you really need in order to install an LPK, and that's a 5/32" punch and a 1/8" punch. Yes, you can install those with a pair of channel locks.

I use a 2 sets of vise grips to set the trigger guard and bolt release pins. Tape them off to prevent scratching. I have them tensioned just right so I squeeze the pins in place in one shot then tap with the correct punch to make flush. I can put a LPK in a bare lower in about 12 minutes or less.

[SFFRONTMAN]

+1 for using the right tools. Post you location so people can offer help if needed. If you are in the San Francisco/ Daily City area I would be more than glad to let you use my vice block and armorers wrench.

[CHS]

Out of curiosity, what kinds of catastrophic failure could occur with an improperly mated barrel to receiver?

Out-of-battery explosion.

I'm not saying it's easy to cause, or that it's likely. I'm just saying that there is always a risk of catastrophic failure in an upper, and almost never a risk in the lower.

[technique]

This walked into a shop I worked at one day....

[dchang0]

Wow, and that was due to an improperly-mated barrel to upper?!

[technique]

Wow, and that was due to an improperly-mated barrel to upper?!

could have been a number of things related or unrelated....He just wanted the stuck case removed from the chamber. So I removed it and that was all.

This is what a failure looks like though...would you like this or anything like this happening close to your face???

[dchang0]

LOL--nope, of course not. I wonder what caused his little problem...

[unamused]

im thinking about picking this up.. any good?

http://cgi.ebay.com/Flat-Top-Receiver-Action-Block-Set-MAGPUL-ACOG_W0QQitemZ290309564363QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4397cc67cb&_trksid=p3286.c0.m14&_trkparms=72%3A1240|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A1|293%3A1|294%3A50

[JohnBrian]

don't forget to use and Anti seize when installing a barrel....you will thank me later.

I use a little white lithium grease. Has always worked well for me!

[JohnBrian]

ARMY TM 9-1005-319-23&P Page 3-40 through Page 3-43

9. Using combination wrench (10) and torque wrench, torque barrel nut assembly (9) to 30 ft-lb (40.5 N-m).

Torque is measured when both wrenches are used together.

NOTE Three times torquing procedure provides for a better thread fit and prevents barrel nuts from becoming loose.

Do not use the torque wrench for loosening.

10. Make certain all three drive pins on combination wrench are engaged with barrel nut assembly (91 Loosen and repeat torque operation. Then loosen the barrel nut again.

Note that the Army technical manual was written in 1996 and calls for the use of aluminum barrel vise blocks, which weren't widely availabe at the time.

My military tech manual is an older version (1970's ?) and doesn't mention the three-torque method. Also, it says to use 25 ft/lbs torque.

I wonder what else I haven't done!