rifle upper on carbine lower

[jlambert2016]

have a 308 carbine I use for hunting. Was thinking of building a 243 rifle length upper to use for precision shooting and long range hunting. unclear if the carbine lower will cycle the bolt properly with a rife length system on top

 

[ORD]

Re: rifle upper on carbine lower

It'll be fine...but depending on which buffer weight/spring you are running, going from the .308 to the .243 may cause issues but not likely.

I have a couple different uppers that I switch out on an Armalite pattern AR-10 lower that has a UBR (carbine buffer setup) installed. One upper is a shorty 16" AR-10 length carbine gas setup while the others are 20" and 24" rifle-length gas systems and they all function flawlessly on the same lower.

 

[Doug Shooter]

Re: rifle upper on carbine lower

You might have to change the buffer and the spring but thats it. Very simple to switch though.

 

[jlambert2016]

Re: rifle upper on carbine lower

its a dpms sportical 16" barrel im not sure what buffer weight or spring is in it other then its a carbine. how would I be able to tell

 

[ORD]

Re: rifle upper on carbine lower

The stock buffer in the sportical is a basic, 3.4oz-3.8oz carbine buffer and basic spring. Nothing special. The concern is if you are running a non-standard part. Personally, a heavier buffer would be better across the board for both your carbine and rifle uppers in either caliber (something in the 5.5oz range or so) like those offered by Slash (aka - Clint Butler) seen here: http://www.heavybuffers.com/ar10carbine.html

 

[Ballista One]

Re: rifle upper on carbine lower

You'll need the equivalent of an H3 Carbine buffer (5.3 ounces).

 

[Inogame]

Re: rifle upper on carbine lower

Shoot it, if it cycles you are good to go. Only look at a new buffer and or spring if you have problems.