I read the tutorial here on how to replace this with a non-nuetered version, but since Bushmaster doesn't sell the FSB seperately, I'm wondering a couple things:

1) Which FSB to use (DPMS, Rock River, etc.), and which will have the best match to the Bushy finish.

2) Will using a different manufacturers FSB make the installation any more complicated, i.e. different pins.

Thanks for the help!

It's going to be a nightmare any way you look at it. Two FSB's from even the same company will most likely have the two holes drilled in different places. There is no set spec for where the holes are drilled.

If anybody can do it and get it right the first time these guys can!
www.adcofirearms.com/shopservices.cfm?page=shop

Thanks for the info. I was watching American Rifleman and they assembled a DPMS AR-15 from parts on the show, and they didn't drill the FSB out, so I figured it would be much easier. I was going to send my upper to ADCO to have the barrel threaded and maybe shortened, and I was going to do the FSB myself. After reading all this though, I think I'm just going to buy a receiver block and wrench, and buy the barrel assembly I want, as this would be just a little more expensive than paying ADCO to cut/thread the barrel and install the f/h, and replace the FSB.