change out upper receivers?  i'm thinking of getting one of the RRA A4 flat top uppers from Pete in NH for my Bushy XM15-E2S 16".....most 'work' i've done on my rifle so far (besides field stripping for cleaning) is change out the handguards and install a forward grip
thanks for the help

also, what are your thoughts on the Elevated Optical Platform upper from RRA?

Propper tools make the job a snap, good barrel wrench, receiver block, lube and torque wrench, we change uppers for anyone who buys em (or barrels) from us (not a cheesy sales pitch but we do 3-4 a week)

The eop is nice, if you plan to do some iron sight shooting in the future (ya never know) you can run into problems my reccomendation is buy a riser on a std A4

Robert
www.rbprecision.com

I have recently changed my A3 reciever for an A1 reciever.  The most difficult part is to buy the equipment.

Briefly (off the top of my head), here is what you need to buy:

1) Upper block (got mine direct from Bushmaster)
2) Armorer Barrel wrench (got mine direct from Bushmaster)
3) 1/16 pin punch (from Sears Hardware)
4) 4" vice (got mine from Lowe's)

And then there is the in-fighting amoung us about if a torque wrench is needed to assemble the barrel.  In my opinion, forget the damn torque wrench.  Go to the next notch that affords a snug-to-tight fit.  The next notch after that is beyond reach.  How does a torque wrench help in this situation where your options are so restricted.

BTW, after you learn to put on a barrel, you will never need to fear the dreaded canted front sight.  You will be able to fix a canted sight yourself.