It has come to my attention, that due to the different contour and shape of the Vltor MUR-1A upper receiver, that my Model1 action block will likely not fit over it.
I’m intending on putting a new barrel and a new Vltor MU-1A uper receiver together. (ie; I’m not looking to take apart an already assembled Vltor and barrel)
My question to you is what tool should I use for the assembly of the Vltor upper and a barrel? Some guys say that the DPMS “claw” block (pictured below)exerts too much pressure on the lugs.
I don’t have one but I use the Panther and have put 60 ft-lbs on a Grendel upper when putting a JP/VTac rifle length rail on and haven’t heard anyhing about putting too much pressure on the lugs. My LMT upper has ben taken down a couple times and had different barrel nuts installed. Most recent is a YHM with 55ft-lbs on my torque wrench. Had I known about the PRI when I ordered my Panther I think I would’ve just gone with that one. Picatinny rail attachment is a nice option.
While I’m at it, here’s a great barrel nut wrench.
I’m definitely going to get that PRI barrel wrench.
It really PO’s me that I went to order it tonight on Midway (it is advertised in their mailed circular), and they were out of it. I should have ordered it last night when they had it, because I could also have saved $10 on their Burris P.E.P.R mount which I intended to order and is on sale through tonight, Sept 30. (Midway sucks that they will not hold a complete order on the side for you for a week until they have everything. They send every little part as they get it in, and will charge you full shipping each time they ship each back-ordered item to you).
If worse comes to worse, I’ll invest another $35-$40 on the dpms panther claw. I feel better putting a Delrin block in a receiver instead of a solid aluminum block like that PRI block. Some-how, perhaps it’s better to have the receiver starting to torque in the delrin block (and give advance warning), then bend or get damaged in a non budging aluminum PRI block.
SHIVAN, thanks for the suggestion of using wood blocks, but I’d only resort to that if what I buy just won’t work.
I’m a tradesmen and no stranger to making my own tools and contraptions when necessary, Here’s a stockade styled tool I made in which two halves lock around a 308 DPMS fftube with dowels that pass through the openings in the tube. I used it to torque off a stuck FF tube while the DPMS upper is locked in a delrin 308 claw in my vise;
There was no strap wrench, WD40, or torch that I tried that was going to remove that FFtube without that 2"x4" stockade turning it off!
The problem is that I’m anal and prefer to use real tools first when possible. I can’t stand scuff marks, marring, slipping, etc.
I take what you recommend seriously, being you’re opinions carry a lot of experience and clout. Was it the aluminum PRI block in the photo that’s posted that you are suggesting?..
Or, are you suggesting the “PRi AR-10/AR-15 combo block” that you mentioned in your post “will also work.”
What tool is that? I looked for it on the web, and couldn’t find it. Thanks.
i use the one you have pictured - you’ll see that although it’s held in place by the lugs, the top part actually engages the charging handle channel inside the upper and supports it there, and at the lugs.
it supports it more than the PRI, which uses the lugs only, if that’s what you’re concerned about.
i’ve used the panther claw for a couple years now… it’s done a few murs, and everything else i’ve done in that time. definitely the only upper block i need. i don’t have any fears. i’ve had some barrel nuts that took my biggest torque extension to crack off- no warped nor cracked receivers.
i’ve done the two blocks in the vise thing- it works, but there are more than a few people who’ve broken receivers doing it like that. puts too much stress on the ejection port cutout. there was a thread here about a guy who broke his doing exactly that a couple weeks ago.
I’ve used the DPMS delrin Panther claw upper block for 60+ installs and have had no problems.
If you’re worried about somehow harming the upper you can use a block of wood across the top of the reciever and turn the upper in the vise sideways with the top of the receiver against one jaw of the vise and the bottom of the DPMS block against the other.
I have two of these DPMS blocks and modified one so that it fits with Daniel Defense Lite Rails. You have to remove material from the front edge of the block so that it doesn’t bind up the aluminum plate that the 6 screws fasten through to the rail.
Excellent thread. It’s now grown chock full of all kinds of helpfull info on the topic.
I’ve already purchased the Model1 armorer’s bock. I’ll just be glad I’ve got it already and focus it mainly on taking apart some of the factory builds which can be pretty tough. (they don’t always put lube on the threads at the factories).
Now I’ll also go ahead and buy a DPMS “claw” and focus that mainly for assembling stuff. (while I save the Model1 block primarily for disassembly chores )Being it works on the inside of receivers, (and not the outside) it can be used for that uniquely shaped Veltor, or most other AR15 receivers out there too.
I’ve concluded that it doesn’t hurt to have an assortment of different tools at $35-$45 a pop. There’s certainly bigger expenses to worry about in life, and not that.
Thanks again guys for all the help. BTW;That You-Tube video link is neat.
most, if not all, the instances of broken receivers i’ve seen have been during removal. like i said, i’ve personally done more than a couple installs with the blocks, and probably some removals.
Im getting ready to do a Aero Precision C.O.P. with a DD CHF barrel,so I think I’ll get a set of the blocks and give them a try for this build.
The way the barrel nut goes on/in the COP,having the receiver turned sideways is a must,and I think that block set is the answer…at least it is according to Armalite.
I’ve used something similar to the PRI block up there, but made of delrin, several times on VIS and MUR uppers.
I turn the upper sideways in the vise, so the vise clamps the bottom of the block on one side and the top of a hardwood block on the other (which in turn is up against the top of the flat-top).
I’ve never had any problems with it, and I’m using a torque wrench so I’m not getting into crazy ft-lbs of torque anyways. It works particularly well when you have a barrel nut that you don’t have to line up with the gas tube.
