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3/7/2010 9:16:47 AM EDT
Fast question if I may. Back in the late 80’s picked up a Colt Match H-Bar put 10
rounds thru it, cleaned and stored till now. Know how to clean it and shoot it but that’s
about it. Back when I picked it up everything was 5.56 now I see 308 and 5.45 are just
as common. Can I change the just the upper to change the caliber? If so what kind of mags do I use?

Thanks to all in advance and remember be kind to an old man.
3/7/2010 9:24:18 AM EDT
[#1]
For 5.45 you should be able to just swap uppers and be good.  I seem to remember S&W throwing in increased-power hammer springs on their dedicated 5.45 rifles for the hard Soviet Bloc primers, but I'm not sure if that's critical or just CYA.  C-products makes magazines.



You won't be able to do .308 on an AR-15 lower.
3/7/2010 9:24:27 AM EDT
[#2]
You can indeed swap an upper of a different caliber onto your lower.
3/7/2010 9:25:45 AM EDT
[#3]
Yes to 5.45, no to .308, which won't physically fit inside the magwell.

Your other common centerfire rifle calibers are 7.62x39 and various flavors of 6.8mm.  There are tons of other, more rare caliber choices in centerfire rifle, and at least a dozen pistol calibers to choose from, as well.
3/7/2010 9:25:58 AM EDT
[#4]



Quoted:


You can indeed swap an upper of a different caliber onto your lower.


Not .308.



There are many other choices though 6.5 6.8 5.45 and lots more....



 
3/7/2010 9:35:33 AM EDT
[#5]
One other question if I may. I seem to remember something about the front pins on the Colts Large v Small ?
Everything should be standard with now with everybody making them. Who is making the best upper now ?
3/7/2010 10:11:43 AM EDT
[#6]
Check out BCM for some nice uppers. Adco can solve the pin issue for $80
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