I would like to try and save some money by replacing my 20" barrel with a 16" and use the same upper receiver. HELP!

I wish I had seen this post earlier.  I just bought a 20" to replace my 16".  We could have just swapped uppers.  Now I've got a 16" I don't need and you've got a 20"!  :)

It's not hard to replace a barrel.  Just need a couple of specialized tools:  A barrel wrench for the barrel nut and an action block to hold the upper receiver.  Plus a roll pin punch for the gas tube retainer pin.

Here are some helpful threads:

[url]http://www.ar15.com/forums/topic.html?b=3&f=4&t=164030[/url]

[url]http://www.ar15.com/forums/topic.html?b=3&f=4&t=164199[/url]

And finally this one...it has a couple of great links about barrel nut torque:

[url]http://www.ar15.com/forums/topic.html?b=3&f=4&t=163946[/url]

I'm in need of a 16 barrel. Would you be interested in selling yours?
Thanks

I've already started a new project for the 16".  I think it's a bad sign when you use an extra barrel as an excuse to start a new rifle build.

It is as easy as pie.  I was always REALLY scared to do the barrel, until I read a similar post about barrel nut torque.  I wanted a Flat top upper and finally decided to go for it.  I was at the Funshow on Saturday and Picked up the upper, barrel wrench (save yourself some time and knuckle skin and pony up the extra bucks for the Heavy Duty Armorers wrench.  TI really helped me out, instead of the small standard ones.  Get a receiver black (A Tony's block was $30 at the show.) It makes a world of difference.  I had never done it before and I am a pro now.  ;) Now I have an upper that needs a mate.  (he he I think I need a M4 barrel, and then I cant put it on a A2 upper so I will need a new flat top and then I still have the A2 so I wil need a new 16" barrel, and then I wil need a lawyer for my divorce cause she will kill me) aww jeez it has started.  Beware it really is a sickness.  I used to laugh at the mentions of it but it really is true.  I did all of the above just to mount a NV scope.