Upper receiver tools

[jackary]

I am a fan of the Midwest URR but I also have a Magpul bev block and a clamshell vice block, the URR is my favorite of the three. Give school of the American rifle a follow, lots of good technical info on the platform.

 

[Cold Smoke]

I’m sitting here cogitating on all the responses which I appreciate immensely. I’m sweating details which really don’t matter. It reminds me of when I was building turbines years ago. When we started final alignment it was all done two hours after dark and would cease as soon as the first ray of sunlight landed on any part of the assembly. Of course all of our sag and operating thermal effects were calculated in by guys with two pocket protectors.

A guy can get all wound around the tolerance axle on the front side and it all flies out the window after the first rapid fire magazine. Probably time better spent for bore uniformity and surface finish. At least try to induce some level of uniformity in the bullets shuddering from the chamber to the muzzle.

It would be interesting to bore gage a barrel every 25 degrees F to see what happens. I suspect it gets tighter the hotter it gets. That and the granular structure probably expands like one of those pooping dog fireworks.

 

[mouthpiece]

Midwest URR

 

[KurtM]

Make sure the receiver is square to the extension, this helps a bit. Thermo fit the extension to the receiver, this help a lot especially when jamming the front end around on a bipod. Make sure there is the very minimum of drag to none on the bolt carrier key to the gas tube. Use good barrel and check that crown. Now you got a great upper.

 

[Cold Smoke]

Make sure the receiver is square to the extension, this helps a bit. Thermo fit the extension to the receiver, this help a lot especially when jamming the front end around on a bipod. Make sure there is the very minimum of drag to none on the bolt carrier key to the gas tube. Use good barrel and check that crown. Now you got a great upper.

Thanks a lot Kurt! As a gemini with OCD issues you have sent me down one heck of a rabbit hole. I may be able to verify whether or not the earth is actually hollow before I’m done.

I’m off to see if anyone has developed a hemispherically floating bolt yet. I can see it in my mind so it has to have been done already.

 

[Camo]

I use a reaction rod and armors wrench. Only special tool needed. Shims when needed to get the hand guards to line up, all other tools are very general.

 

[Cold Smoke]

I use a reaction rod and armors wrench. Only special tool needed. Shims when needed to get the hand guards to line up, all other tools are very general.

Found out the proper name for what I was calling a trunnion bar. I can see how you might fubar the alignment notch on an upper if the pin is the only anti-rotation element during a torquing sequence.

I’m coming to understand that while building these is a lot like playing with Barbies, they’re more like Faberge’s version.

 

[Camo]

Found out the proper name for what I was calling a trunnion bar. I can see how you might fubar the alignment notch on an upper if the pin is the only anti-rotation element during a torquing sequence.

I’m coming to understand that while building these is a lot like playing with Barbies, they’re more like Faberge’s version.

Guess some people call it by a different name but the tools name is a reaction rod. That’s how you order them by name.

 

[JEVapa]

Found out the proper name for what I was calling a trunnion bar. I can see how you might fubar the alignment notch on an upper if the pin is the only anti-rotation element during a torquing sequence.

I’m coming to understand that while building these is a lot like playing with Barbies, they’re more like Faberge’s version.

It's called something different by each manufacturer. I figure if you use "action" and "rod" in the same sentence, everyone will figure out what you're saying. Or "Trunnion Bar" I knew what you were saying even though you violated AR15 in-flight repair protocols and offended all of AR15DOTcom. lol

Geissele calls it a "Reaction Rod"
Wheeler calls it an "Action Rod"
Midwest Ind calls it a "Receiver Rod"
Real Avid (the guys with all the Klingon looking weapons/tools) calls it a "Lug-Lok Vice Block" No Action or Rod anywhere...some real avid rebels.

Brownells has one called a barrel extension torque nut or something. It's pretty cool because you put the barrel nut wrench in a vice horizontally, put the URG barrel down in the wrench, stick the torque rod nut thing in the extension, and use a 1/2 drive torque wrench to turn the whole thing. It's probably more complicated than it's worth.

AR-15/M16 BARREL EXTENSION TORQUE TOOLS | Brownells

Handy tool aids in applying straight-line torque for fast, easy installation of the barrel nut without scratching the exterior of the upper receiver. Helps ensure the right amount of torque is evenly applied, while maintaining proper alignment of ...

www.brownells.com

 

[Cold Smoke]

It’s kind of funny. I was watching an interview with the guy who owns Foxtrot Mike. They were discussing some of the details that he put in hs own designs after doing contract design work for other companies. The flats milled on the barrel behind the muzzle device was probably the biggest face palm idea ever for ARs. LOL His reutilization of the AR 180 recoil system makes me wonder why we still fight the buffer tube/receiver extension. The charging handle is favorable to the rear number all day.

I’m starting to make myself wonder why I even want to mess with the dang things...