ar lower compatability for 308 vs 223 - The Firearms Forum

lslubecki · 05-10-2006, 06:05 PM

Can I put a 308 upper on a 223 lower? I found a RRA 223 lower reasonably priced locally and when I asked if a 308 would fit he didnt know. He said it was a 223 lower and didnt have any 308 lowers. I didnt know there was a difference. Thanks for any answers.

Steve Lubecki

southernshooter · 05-10-2006, 09:15 PM

That I don't know. But You can get a .50 kit

wolfgang2000 · 05-10-2006, 10:17 PM

The short answer is NO. The magazine well on the 308 is larger than the 223 version.

LDBennett · 05-11-2006, 06:58 AM

Islubecki:

The magazine well is not long enough for the 308 cartridges. You can do the 50 cal because the conversion is to a single shot bolt action one and the AR lower is used for a handle and as a hammer/trigger system. The magazine well is not even used (the 50 cal conversion is a single shot).

The AR10 (308cal) is a pysically bigger receiver but I think the internal trigger system is interchangable between the AR15 and AR10 (???). The upper receiver, of course, has to be longer as well so that the bolt area will accept the longer fatter 308 cartridge. What is possible is the several roughly 25 caliber wildcat cartridges like the grendel (at least one other) but these are not yet readily available either for ammo or for conversions. There are 22LR conversions avaiable where it is an insert in the original barrel or a complete new upper receiver.

LDBennett

lslubecki · 05-11-2006, 08:18 AM

Thanks for the reply. I never even thought about cartridge size. DUH! It all makes sence now.

Steve Lubecki

southernshooter · 05-11-2006, 11:03 PM

ISLU the .50 cal kit I found is semi-auto with a 7-round mag from http://www.cabelas.com/cabelas/en/te...RFX_xtspring06

lslubecki · 05-12-2006, 09:00 PM

OOOO! Bolt on .50! My wallet feels lighter already.

Steve Lubecki

tankerman · 05-14-2006, 03:31 PM

What kind of upper is it? If you can't find lower in your price range I may be interested in buying the upper

05-10-2006, 06:05 PM	#1
lslubecki V.I.P. Member Join Date: Mar 2005 Posts: 81	ar lower compatability for 308 vs 223 Can I put a 308 upper on a 223 lower? I found a RRA 223 lower reasonably priced locally and when I asked if a 308 would fit he didnt know. He said it was a 223 lower and didnt have any 308 lowers. I didnt know there was a difference. Thanks for any answers. Steve Lubecki -->

05-10-2006, 09:15 PM	#2
southernshooter Advanced Senior Member Join Date: Mar 2006 Location: Deep South Mississippi Posts: 5,943	Re: ar lower compatability for 308 vs 223 That I don't know. But You can get a .50 kit __________________ Only you can see this

05-10-2006, 10:17 PM	#3
wolfgang2000 Senior Member Join Date: Dec 2005 Location: Mountain Grove MO. Posts: 542	Re: ar lower compatability for 308 vs 223 The short answer is NO. The magazine well on the 308 is larger than the 223 version. __________________ Guns are like Jello, there is always room for more!

05-11-2006, 06:58 AM	#4
LDBennett Advanced Senior Member Join Date: Dec 2003 Location: Hesperia, CA Posts: 5,715	Re: ar lower compatability for 308 vs 223 Islubecki: The magazine well is not long enough for the 308 cartridges. You can do the 50 cal because the conversion is to a single shot bolt action one and the AR lower is used for a handle and as a hammer/trigger system. The magazine well is not even used (the 50 cal conversion is a single shot). The AR10 (308cal) is a pysically bigger receiver but I think the internal trigger system is interchangable between the AR15 and AR10 (???). The upper receiver, of course, has to be longer as well so that the bolt area will accept the longer fatter 308 cartridge. What is possible is the several roughly 25 caliber wildcat cartridges like the grendel (at least one other) but these are not yet readily available either for ammo or for conversions. There are 22LR conversions avaiable where it is an insert in the original barrel or a complete new upper receiver. LDBennett Last edited by LDBennett; 05-11-2006 at 07:00 AM..

05-11-2006, 08:18 AM	#5
lslubecki V.I.P. Member Join Date: Mar 2005 Posts: 81	Re: ar lower compatability for 308 vs 223 Thanks for the reply. I never even thought about cartridge size. DUH! It all makes sence now. Steve Lubecki

05-11-2006, 11:03 PM	#6
southernshooter Advanced Senior Member Join Date: Mar 2006 Location: Deep South Mississippi Posts: 5,943	Re: ar lower compatability for 308 vs 223 ISLU the .50 cal kit I found is semi-auto with a 7-round mag from http://www.cabelas.com/cabelas/en/te...RFX_xtspring06 __________________ Only you can see this

05-12-2006, 09:00 PM	#7
lslubecki V.I.P. Member Join Date: Mar 2005 Posts: 81	Re: ar lower compatability for 308 vs 223 OOOO! Bolt on .50! My wallet feels lighter already. Steve Lubecki

05-14-2006, 03:31 PM	#8
tankerman Member Join Date: May 2006 Location: OC Posts: 3	Re: ar lower compatability for 308 vs 223 What kind of upper is it? If you can't find lower in your price range I may be interested in buying the upper