To remove and install a barrel do you recommend a multi-tool like DPMS or just use the USGI tool with a torque wrench.
To grease up the threads, I know everyone says to use moly grease but I bought a bushmaster armorers DVD and they assembled using only motor oil on the threads.
(just an FYI, bushmaster used a USGI tool and torque wrench for the barrel nut)

If I don't need moly grease then I won't buy any but that seem to be the standard here.
A lot of people here also say not to waste money on a torque wrench, and just use the multi-tool until tight.

They also did not use an action block but used a barrel vice but I am going to get an action block.

I have to buy everything to do this so keeping the "extra" tools that I don't need off the list would save me some cash.

Any suggestions would help.
Thanks

I have done 3 barrels so far, and use standard automotive grease (good up to 320* F), an action block (highly reccomended), and the armorer's wrench Bravo Company USA sells (which is much like the DPMS tool IIRC).  

I'd recommend a "multi-tool" armorer's wrench over the standard USGI wrench. The USGI wrench only has three pins, which makes it easier to strip the teeth on the barrel nut. The "multi-tool" wrenches grip most of the barrel nut's teeth, and make slipping less likely.

I'd also recommend the action block, as it is too easy to damage something trying to barrel an upper using barrel blocks. That's probably the reason so many Bushmaster uppers are showing up with canted barrels.

The reason lubricant is used on the barrel nut threads is to make sure everything is nice and smooth during the tightening process. I recommend a torque wrench in order to avoid under or over torquing. The specs say to tighten to 30#, then toss the torque wrench as it is no longer needed. If the barrel nut doesn't have a notch aligned for the gas tube at 30#, you are supposed to tighten (without the torque wrench) until the next one aligns.

I use the DPMS block and DPMS wrench. I also use grease on the upper threads.

I recently did my first upper build.

I bought my armorers wrench and upper vise block from Bravo Company. I already had the torque wrench and a vise.  I got the moly grease at Auto Zone for $2 (it was a big bucket too).

With the right tools, things go together easy.  If you don't have a torque wrench or vise, those are easily borrowered from neighbors or friends to save money.

Actually the only thing I have is a vise, but I need the tools.

The tool from bravocompany looks exactly like the bushmaster one, but do you really need a torque wrench?

I don't know if I can borrow one from anyone that I know.

Quoted: ...but do you really need a torque wrench?

Many don't use one, but the key is not to overtighten. Does your elbow click at 30#?

You can buy a torque wrench for AR building for $12:

www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=239

Don't worry about it being inexpensive. Its only use is to reach the 30# minimum.

Thanks for the linky, normally I would have looked at sears or home depot, and then looking to dish out over $50 for one.

I just got the multi-tool from DPMS. It list for 33.95 but had a 13.00 multi-tool discount for a total of 20.95. Cant hardly beat that. And any order over 25.00 is free shipping.

If you grease up the threads, won't that cause a false torque reading or are there 2 different torque specs, one wet and one dry?

Several car parts stores have tools you can rent. You put a deposit down and they let you have it a day or so.  When you bring it back, you get your deposit back.  I am almost certain that they would have torque wrenches.  Just an idea.

Quoted: If you grease up the threads, won't that cause a false torque reading or are there 2 different torque specs, one wet and one dry?

AR-15/M16 barrel nuts are supposed to have lube on their threads, so it's safe to assume that the torque specs will be for "wet".

Quoted: To remove and install a barrel do you recommend a multi-tool like DPMS or just use the USGI tool with a torque wrench.

You can use either.  If you read the thread tacked at the top... you will understand why a torque wrench is not required.  It doesn hurt for the incredibly anal, however.  

To grease up the threads, I know everyone says to use moly grease but I bought a bushmaster armorers DVD and they assembled using only motor oil on the threads.

The bushmaster video is fine.  However, it does not follow the TM in that respect.  The point is to get a wet torque setting, and to stop any binding/galling during the tightening of the barrel nut.  Using Moly Grease (or any generic high temperature grease) will ensure that the barrel can be disassembled in the future without any damage to the upper receiver threads.

(just an FYI, bushmaster used a USGI tool and torque wrench for the barrel nut)

Which isnt bad... but I dont consider Bushmaster the authority on barrel installs.... nor do I know that they actually use the same methods in their video... in their shop.

If I don't need moly grease then I won't buy any but that seem to be the standard here. A lot of people here also say not to waste money on a torque wrench, and just use the multi-tool until tight.

I use grease (a $1 tube will last your lifetime) and do NOT use a torque wrench.

They also did not use an action block but used a barrel vice but I am going to get an action block.

That shows how old and outdated that video, or armorer is.  That is the old way... and puts stress on the barrel extension indexing pin to the uper receiver slot... which increases the likelyhood of a canted FSB.  Get an action block.

I have to buy everything to do this so keeping the "extra" tools that I don't need off the list would save me some cash. Any suggestions would help. Thanks

I suggest you read the thread tacked at the top, which pretty much covers all of this.  

Quoted: Many don't use one, but the key is not to overtighten. Does your elbow click at 30#?

Mine does.  

Ordered everything I need (except moly lube) it cost me about $112 for everything.

DPMS Multi-tool -dpms
USGI tool (got this just incase) -dpms
1/2 clicker torque wrench - harbor freight
snap ring pliers - harbor freight
3 piece action block - bravocompanyusa

Should be ready to go.

Get a decent little punch set?  I use craftsman punches, so I can return the 1/6" punches and get new ones when I break them.  I use a cheap brass punch set for misc stuff.

You need to get some wood blocks to support the barrel for drivinh out FSB pinis, or the brownells block.

I have a steel punch set I picked up at Lowes.  Works good for roll pins.
It has a 1/16" and 1/8" basically all you need right?

Quoted: It has a 1/16" and 1/8" basically all you need right?

For the most part.  I use 1/4" brass ones sometimes... but it aint required.  Just be careful when using steel punches.  Brass allows for a little more "fudge" factor.... and tend not to spread/damage a roll pin when they are really tight.

I am kind of like Adam Sandler in Happy Gilmore........ Just tap it in.... give it a little tapy tap tap....

By the way the action block that I ordered, 3 piece set,  looks like it comes with a long T shaped piece.   Where does that go?

www.bravocompanyusa.com/Page5.html

The T shaped piece replaces the bolt and carrier , and charging handle.

Quoted: The T shaped piece replaces the bolt and carrier , and charging handle.

Yep - it is supposedly to keep you fron crushing your upper receiver.  In my opinion... it isnt needed.... if you crush your clamp hard enough to bend the aluminum... that piece might save you from totalling it... but some damage is likely already done.  I guess it is something like idiot insurance....  You just dont clamp down on the action block tightly... just tight enought to hold it in place without falling.

I just took off my FSB. I was having trouble with the tiny 1/16 punch bending so I used a 1/16 hex head bit with a 3 inch extention, worked great. The FSB pins took plenty of wacking, dinged up the end of a brass punch real good. Once the pins were started I used a larger hex head bit in the same extention to finish driving them out. The hex head bits seem a little sturdier to work with (if you dont have the right tools).

but I bought a bushmaster armorers DVD and they assembled using only motor oil on the threads.
(just an FYI, bushmaster used a USGI tool and torque wrench for the barrel nut)

Nice that Bushmaster was mentioned... they were famous for their canted front sight bases.

I just use a GI barrel wrench and a 1/2" breaker bar, no torque wrench.

Grease... wheel bearing grease usually contains moly disulfide.  Also, regular grease as is used in a grease gun will work just fine.  Nothing special needed.