AR15.Com Archives
 Multi-caliber AR-15 lower receiver
szairborne  [Member]
10/31/2011 3:21:19 PM EST
I have a quick question. For my build im using a Multi-caliber lower receiver. From my understanding i can use pretty much 5.56, 223,6.5 creedmoor, 6.8 spc, 5.7, 243, 5.56x54 uppers. Am i correct on this statement?


Thanks in advance
Shayne
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TCBA_Joe  [Team Member]
10/31/2011 3:38:35 PM EST
Yes, but not because it's engraved "multi".

You can run whatever AR upper (regardless of caliber) on any AR lower (regardless of markings)
Browning_guy  [Member]
10/31/2011 3:52:46 PM EST
Originally Posted By szairborne:
I have a quick question. For my build im using a Multi-caliber lower receiver. From my understanding i can use pretty much 5.56, 223,6.5 creedmoor, 6.8 spc, 5.7, 243, 5.56x54 uppers. Am i correct on this statement?


Thanks in advance
Shayne


If I'm not mistaken, you CANNOT use 6.5 creedmoor in an AR-15 lower. I think that requires an AR-10 lower, but I could be wrong. You might have meant 6.5 Grendel in which case you would be good to go for any of the calibers you mentioned.
szairborne  [Member]
10/31/2011 3:57:40 PM EST
Thanks guys!
thepinkmist  [Member]
10/31/2011 4:00:32 PM EST
Originally Posted By TCBA_Joe:
Yes, but not because it's engraved "multi".

You can run whatever AR upper (regardless of caliber) on any AR lower (regardless of markings)


+1. the caliber engraving does not lock a lower reciever into a certain caliber. most AR lowers now come with multi for the caliber because variants are becomming more and more popular so the manufacturers decided putting multi would be a little more appropriate. you can use google or look in the AR variant forum and find all the other 92 cartridges that can be fired from a standard ar15 lower.


243 will not work in an ar15 upper IIRC, it needs an AR10 lower.
Russ4777  [Team Member]
10/31/2011 4:02:51 PM EST
There are many other caliber uppers besides what you have mentioned that can be fitted to an AR-15 style (short action) lower.
szairborne  [Member]
11/1/2011 2:28:53 AM EST
This is good information, thanks for the clarification on the 243. Im trying to get a setup that is fun for me, but also for my two daughters who also love to shoot.

Thanks
Shayne
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