I just ordered what I hope will be the last of the parts needed to officially assemble my 6mm arc rifle. I knew going in that the standard upper receiver clamshell clamp wasn't going to work with the mega arms thick walled receiver. I had always kinda figured I would need an action rod like the midwest industries unit. https://midwestindustriesinc.com/upper-receiver-rod/ So I started watching videos on various ones to see if there was any down sides besides cost, and came across this video. https://youtu.be/C4AHiVGdfFQ?si=-4j5sm9itNBVrbPN

I didn't realize the barrel extension was a seperate part of the barrel. So this brings me back to the idea using a barrel clamp vise instead. Now on a barrel that is always tapering I can see them being a PIA. But my heavy profile barrel has a major constant thickness section other than the flutes that could be tricky to clamp to maybe? I have read, and it makes sense that the barrel vise is the safer way to torque the barrel nut down and muzzle device as the barrel takes all of the load.


Any thoughts?

It's always seemed to me that when torquing the barrel nut, the force is being transferred to the upper receiver, so that's what should be held. The risk when clamping the barrel is the barrel index pin can deform its notch in the upper, and the barrel will rotate in the upper. The MI rod seems like the best way to go when a clamshell won't work, maybe better than a clamshell since it holds the barrel in line with the upper. I've used the Magpul BEV Block, with a bolt carrier added for support, on at least one build. The BEV Block extends into the charging handle slot like the MI tool, to a lesser extent.

I've read contrary opinions on this from folks that sounded like they knew what they were talking about, so, YMMV.
Ideally, clamping the barrel and the upper would be the way to go.

Clamp the barrel for muzzle device work. I unscrewed a Wilson Combat 308 barrel extension using a barrel extension wrench when changing a muzzle device. Might have been undertorqued, WC replaced the barrel.

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ive done a few builds now with the Midwest URR. Ive got both the ar15 and the 308 versions. I havent had any issues with them but these have been new builds so the threads were all good. I did use them to remove some muzzle devise as well (moving them around) and never had issues either.

Think the main thing with them is making sure things are torqued correctly. And also using heat or whatever is needed on muzzle devices and not just brute strengthing them off.