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1/31/2016 9:14:57 PM EDT
Hi Everybody!

I have a preban Colt HBAR (.223) that I am working on (was built right before the '94 ban). Right now it is all stock except for the grip and the stock but I would like to try my hand at building an upper for it. My primary goal would be to set it up for use in 3 gun competitions. I've never built an AR-15 upper and really don't know where to start. I know with the older ARs there can be some differences you need to watch out for when it comes to the uppers but I'm not really sure where to start or what to look out for. Any advice on what I need to keep an eye on or even suggestions for how to build it would be much appreciated. The only thing I know I really want on it is a CIM handguard, other than that it's all up in the air!

Thanks in advance!
1/31/2016 9:39:29 PM EDT
[#1]
I M working on my first AR build too. Lot to learn huh?

It sound alike you got the first part figured out.

For 3 gun.  From what I read, and seen here are a few things to consider.
18-20 inch stainless steel barrel for accuracy (chrome can help in addition for longevety).  Some manufacturers have slightly moa advantages in barrel accuracy  Than others.  Rock RIver arms is an decent mid  level upper.
The ones I seen have single Picatinny rail systems for the top mount of sights.
Make sure the handguard is free floating for more for more improving accuracy.
Muzzle brake reduces recoil
The other things to consider are, light triggers such as a timney.  3-4 lb pull.
Another thing the book mentions is lighter buffer in the stock to reduce recoil.  Trial on error on this one.
Tricked our  bolt carrier that Cycles faster can help.
Adjustable gas block to reduce e recoil too.
Most these modifications will reduce reliability of the ar though.
There are two ways to go about this. You can buy a complete upper half and modified from there or buy it piece by piece.
I if u are building  piece by piece, make sure the upper receiver match the barrel. M4 to m4.  Also a check Gage helps to see if it comptaible.
1/31/2016 9:55:56 PM EDT
[#2]
Read this does a very good job of laying it all out for you in a good step by step instructional with pictures.
1/31/2016 10:44:17 PM EDT
[#3]
Do you have a "big hole" pivot pin? If so your options in uppers are severely limited, or else you have to use an adapter pin.

The type of sear block in your lower will determine what bolt carriers are compatible, unless you remove it.
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