I have 2 SBR builds that I will be doing uppers for soon (my first upper builds).  One is a conventional free float upper - the other is an Aero Arms Monolithic upper.  I am under the impression that a barrel clamp is the preferred method to hold the upper while torquing on these.  That said that is pretty impossible with an SBR and a Monolithic upper.  What is the next best solution.  I suspect that the gas block and flash hider could be installed with a barrel clamp before installing the barrel - I am currently going to be using a thread on suppressor until this gun gets its dedicated suppressor (with a trifecta attachment).





What is the general sequence of installation (barrel nut, flash hider, gas block) and how does that need to be changed with a monolithic upper (with essentially -0- fully exposed barrel (bottom half is exposed) and and a covered gas block).





The lower castle nut is also not up to torque yet - assume best method is to install it on a stripped lower held in a clam-shell block, with the alternative of using a magwell block.  That said - saw plenty of discussion about 40 ft/lbs being somewhat excessive.  Feedback on this would also be appreciated (second lower should be in the mail today).





Should either of these threads be greased?

 

this and only this geissele reaction rod nothing else is needed for holding anything when building a upper ... and its always barrel nut then gas block then flash hider ... use a slide on gas block and install the tube first to the block then slide it on as one unit and since the bottom is open a set screw block or bottom clamp one should be used

forgot yes you should grease the threads of the barrel nut with areoshell and if you are going to be taking the flash hider or can off a lot you might put some but many don't .... this is the only place I have found that sells areoshell in small amounts and isn't a arm and a leg areoshell

I ended up buying from this guy. Quick shipping too.

http://www.ebay.com/itm/AeroShell-Grease-33MS-Synthetic-with-Moly-for-Extreme-High-Temp-Pressure

Used the ebay grease.  Good price and should work as needed.  Went with a Brownell style tool (from LGS) rather than the Geissele one, as it was $40.  Good news is it worked for one of the 2 builds, bad new is sheared the barrel pin on the other.





I will keep the tool for muzzle brakes - but probably not use it often to mount barrels since now I have to deal with a damaged barrel.  Please insert list of curse words here.  FWIW I read other posts where people had similar issues with barrels from that manufacturer (they used the Geissel tool and Giessel made it right for them).  I highly suspect the pin was too soft.  Does not really matter though - if I would have clamped the upper, no stress would have been on the pin.  It sheared at 60lbs, which is what I had to do to get the index on the front free float tube correct.



I used punches to insert the gas tube pin and gas block pin.



At the end of the day, not really enjoying assembling uppers.  Inserting those pins has to be a job more suited to a tool.

I just went through just about all of Aero's site and didn't find anything about how THEY suggest assembling their monolithic uppers.  Did anything instructional come with the upper, like a specific torque to tighten the barrel nut to?  I would think that they'd provide that sort of information with their products.

I guess I will fill in this additional info.  I was building an Aero Monolithic and a standard free float.  I had no problems with the Aero because their nut does not need to be indexed.  I torqued a bit light - but I think it will be enough.  I might check it after a few rounds.  



The problem was a standard upper with a freefloat tube.  It indexed poorly, tried again, then gave up and tightened it 10lbs at a time to get it indexed (but keeping under the spec max).  When it was niced and indexed I saw the gas port hole was about at 1pm, and stripped it down knowing exactly what happened.  There is also some damage to the upper - but I think it is not critical (threads got banged up near the pin hole)