Need help replacing upper receiver on AR

[hoghunting]

I'm asking for information or advice for my AR. I have a Colt AR with the carry handle upper receiver and I want to replace the receiver with a flattop. Besides the gas tube and the other parts in the upper, is removing the barrel nut and barrel and installing them on the new flattop all that is needed for installation? Do I need to do anything else? I will be using a receiver block for the barrel removal and install. I haven't worked on an upper receiver before just want to be aware of any surprises.

Thanks for your help.

 

[nicholst55]

Sounds like you've pretty much got it. I believe that AR-15.com has the Army TM online, so you can see how it's done with the minimum amount of tools and equipment.

I can't access that site from my location without running a hotspot shield, or else I'd give you a link. You can also access it from Bigger Hammer.net, here: http://www.biggerhammer.net/manuals/

 

[loadedround]

Hoghunting: One small additional suggestion, If you are mating a Colt receiver with an aftermarket upper, you will need to get a pivot pin adapter to mate the Cole lower to your new upper since the pivot holes are different diameters. This is true with the older Colt lowers and I'm not sure if Colt ever changed over to the standard size. This happened to me wihen I bought a DPMS flattop upper for my Colt. This adapter is available from Brownell's or MidwayUSA for about five or six bucks.

 

[hoghunting]

Thanks to both of you for the help. I checked AR15.com and confirmed what I thought I needed to do. I have an offset receiver pin as I also have a completed upper in 7.62x39. But I ordered an extra one when I ordered the tools. If I hadn't gone through the process of installing a different upper, I would not have known, so, thank you for the suggestion, as someone else might also learn from it.