I think the reaction rod comment is because different billet uppers, depending on their exterior dimensions, may or may not fit into whichever upper vice block you have. But, a reaction rod will always be able to mate up with the barrel extension.
As far as I know, that's the only way to install the barrel nut on a billet upper. I've never seen an upper vice block made for billet receivers, and even if there were you'd have to have one for every different receiver on the market, whereas the reaction rod will work with all of them. Magpul also makes something called a bev block, but the reaction rod is far superior.nate, very cool build! i'm working on something like that myself
grampa, yep and thanks. I'm a big fan of the KMR and have built several rifles with them. You lost me on the billet upper comment though. Why do they need a reaction rod?
definitely allowing all types including varmint. the "carbine course" is really just a couple hours to familiarize them with the concepts of mag changes and malfunction drills. I'll loan them a carbine if they can't safely manipulate their 20lb bench gun
will definitely review people's BOMs to make sure they are going to work.
I'm assuming you're talking about those DPMS blocks. Those are fine for certain things, but they're not okay for installing barrel nuts or muzzle devices. They place way too much stress on the receiver, especially if you're going up towards 80 ft lbs. There's a reason why not many people use them.If a billet upper will fit on an AR lower, it will fit on an upper receiver vice block
thanks nastynate!
guys, i'm really just crowdsourcing templates to make it easy for n00bs. for example, if they like the way nate's rifle looks, here's the list of stuff to go buy to build one like it.
I've never heard of the Reactor Rod, but it sounds like a knockoff. The Reaction Rod from Geissele (the one with the NSN number) is by far the best tool for the job. You're not going to hurt anything as long as you stay inside the 80 ft lbs max. It's used by untold numbers of armorers and no issues.
The DPMS style block puts all the stress on the takedown lugs, which weren't meant for that. It's the absolute worst tool for the job. People report snapping off the front takedown lug with those on a regular basis. I can't imagine why they still sell them.
If you don't want to spring for the reaction rod, then your next best option is to put the receiver into the vice sideways with some sort of stiff padding. Cutting boards seem to work the best. I've never tried this, but it's reported to work. Personally, I would just spend the 100 bucks on the reaction rod. You'll look more professional, nothing will get broken, and you'll be more likely to get good word of mouth.