[ARCHIVED THREAD] - stupid question

Posted: 7/22/2009 10:37:44 AM EDT

excuse my ignorance but what exactly is the difference between a 5.56 lower and a 6.8 lower? Can you put a 6.8 upper on a 5.556 lower, or vice versa? I was entertaining the idea of purchasing a Stag 7H upper but was unsure if it could fit on my 5.56 lower. I assumed it would until I saw specially stamped 6.8 lowers, the only other time I've seen this is with the ar10 in.308. Again I apologize for my stupidity just trying to learn every thing I can about this damn sickness I seem to have caught. TIA

ellswj

Posted: 7/22/2009 10:45:16 AM EDT

[#1]

Yes, you can put a 6.8 upper on a lower stamped 5.56 and vice versa. The only difference between a 6.8 AR and a 5.56 AR is the barrel and bolt.

ETA: and the magazines, if you want to get really technical.

Posted: 7/22/2009 10:45:22 AM EDT

[#2]

One in the same.

Posted: 7/22/2009 10:54:31 AM EDT

[#3]

sweet, thats what I thought but I had just never seen any lower stamped for a different caliber like that

Posted: 7/22/2009 10:55:46 AM EDT

[#4]

Essential arms makes a lower stamped 6.8 if you are wanting one that matches.

Posted: 7/22/2009 1:31:51 PM EDT

[#5]

all lower receivers will accept a 6.8 or 5.56 upper (or lots of other calibers for that matter). only difference in 6.8 and 5.56 upper is the actual barrel and the bolt. you'll also need different magazines for 6.8 and 5.56

Posted: 7/22/2009 2:13:41 PM EDT

[#6]

Quoted:
sweet, thats what I thought but I had just never seen any lower stamped for a different caliber like that

Many lowers don't have a caliber listed and instead are stamped "MULTI".

MEGA for instance:

[ARCHIVED THREAD] - stupid question

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[ARCHIVED THREAD] - stupid question

[ARCHIVED THREAD] - stupid question