I've got a 20", bone stock RRA Varmint rifle in .223 that I'd like to swap out the aluminum tube for a free floated rail. I've assembled a lower receiver or two and done some other minor gunsmithing (note: NO machining...simply assembly/disassembly/tinkering/adjusting/etc.) on various makes/models of firearms, but I've never messed with an upper receiver. I've read, read, and read some more and have only become more confused. I found a thread on m4carbine.net that says that I'll need a new barrel nut, but that the Wilson barrels that RRA used on these uppers have an oversized barrel tenon that won't fit through a standard barrel nut and the barrel will need to be turned down or the barrel nut opened up. THIS task I'm not comfortable with, as I don't have the tools required and I'd like to keep the .75 MOA accuracy that I'm currently getting. I'd be more comfortable doing this and screwing it up without asking any questions if I hadn't read about the barrel tenon being 1.050" and the barrel nut being only 1.000". But that reading required that I beg the question.
I'm not dead-set on the make/model of rail I'd like to use and don't really have any brand loyalty regarding this issue, so I'm open to suggestions here as well. One question I do have is what length would be desirable? I'd rather not have to change the gas block, as I'm already looking at buying a quad-rail, barrel nut, and maybe even a delta ring ass'y.
I'm not dead-set on the make/model of rail I'd like to use and don't really have any brand loyalty regarding this issue, so I'm open to suggestions here as well. One question I do have is what length would be desirable? I'd rather not have to change the gas block, as I'm already looking at buying a quad-rail, barrel nut, and maybe even a delta ring ass'y.
