11/12/24 - edited to add that I just watched the video that Aaron suggested…it goes over the 3 tools. 

In a nutshell, the finned URR from Midwest is 1….but not 100% idiot proof cause there is some slight slop.  The BB is okay.  The clam is ok.  On tuff jobs, he uses the URR and clam together

He thinks unfinned RR’s are ok for muzzle devices




My old post before seeing the video:
All 3 should be fine for barrel nuts as all 3 hold the upper  right? (clamshell holds exterior, bev and RR hold the locking lugs)

For a properly installed barrel nut (60-80lbs), it sounds like using all 3 (clam, BB, RR) are ok for installing muzzle devices. I assume because of the pressure between the receiver/barrel/nut they become “one”.  So you can just hold the receiver instead of the barrel itself when installing MDs

I read somewhere that alluded to manufacturers (rock river, noveske, windham/bushmaster) using RR’s to build their rifles

That said I still rather be safe than sorry when installing MD’s.  So I still put my barrel in a clamp

My reason for asking is I’m thinking of getting a Midwest URR reaction rod.   But when I think it thru….. I don’t think I really need it.  My clam and BB are good enough for barrel nuts

That said, a URR reaction rod does seem more versatile and/or easier to use in some situations.

What are you folks using? 

Does the fin on URR make a big difference compared to an unfinned RR?

Considering just getting a barrel vice instead….a cheap wheeler vice $90 or bison vice $75

clamshell works well but it may not fit all upper receivers i.e. proprietary designs, billets. If installing handguards like the Larue the clamshell will need to be relieved to accommodate the locking ring. The barrel nut is torqued onto the receiver so obviously that needs to be held. The RR holds onto the barrel extension lugs and transfers that torque to the index pin when engaging the barrel nut. The Midwest and the improved  Geiselle RRs have parts that engage the upper receiver and should transfer the torque across the receiver instead of the pin. Clamshells are cheaper but take up more room than a RR. An RR would replace barrel clamps when installing a muzzle device. Clamshells shouldn't be used to install muzzle devices though the torque specs on a typical FH is smaller than a barrel nut. The torque would transfer to the indexing pin if installing a muzzle device with a clamshell.
I'm tempted to get a Midwest RR but I always pull myself back with why? Clamshell and barrel clamps work well and many barrels later. $100 gets me a few plate lunches at Times and that's a month's worth of gas for my car....Pake life is hard....

Ren
Thanks for the explanation.  You saved me from spending money on a URR and a barrel vise.  My pake ancestors also thank you :-)

I haven’t assembled an upper in a while and forgot the locking lugs are part of the barrel extension….not the upper receiver

Barrel nut:
I guess the BB and the unfinned RR’s are not ideal ….but generally still work because properly made receivers and index pins can handle the 60-80 ft lbs of torque to install a barrel nut

Muzzle device:
So after more reading - the extension is screwed on to a barrel at 150-175 ft lb

An unfinned RR or BB should be fine for MDs because only 20-35 ft lbs of torque are needed for a muzzle device

I assume the MD is threaded so that any torque would only “tighten” the barrel nut onto the barrel (barrel extension won’t tighten anymore from only 20-35 ft lbs ….same as if I tried to torque the MD with my fingers l)

And 20-35 ft lbs, even if in the other direction would not be enough to unscrew the barrel from the extension.   Extensions are very difficult to remove…..so no stress on the index pin or the slot for the pin…torque goes to the extension…which goes to the RR or BB

I use MI URR. The spine that goes down the charging handle channel ensures nothing twists. That said I've done plenty of uppers using some knock off reaction rod that's similar to geissele reaction rod by botach. I forgot the name. Kleyzon??

But now I only use the URR.

https://youtu.be/7FemsC5JStw?si=DMjnASVjEXpH7lK6

Watch that video. Very informative IMHO.

The feature I like about the G RR over the MI RR, is that when you're assembling the upper, you can clock the receiver to give you the best angle for whatever you're doing at the moment.

I have both.

I personally wouldn't use a clam-shell for torquing a barrel nut.  nerd-geek reasons.

Aaron - thanks!  That’s a good video.. linked it again in my first post

Rpol - good point about the G RR