Building the AR-308 is a slightly complicated task, because it was never widely adopted by the U.S. military. Thus, there is no mil-spec for this rifle, like there is with the AR-15. Our AR-308 80% lower receivers are based on the DPMS generation 1 pattern, so when purchasing upper receivers and magazines, make sure that they are that pattern as well.
The original design for this rifle was done by Armalite, and it was called the AR-10. However, Armalite AR-10 pattern upper receivers do not match up with our AR-308 pattern lowers. It’s good to do some of your own research, and make sure that everything matches up to our DPMS generation 1 pattern lower receiver.
A good website to use as a reference on this matter is https://308ar.com/articles/compatibility/.
You can see the major differences in the image below. The Armalite AR-10 (top) has a very slanted and angular cut on the lower and upper receiver, whereas the DPMS Generation 1 pattern AR-308 (bottom) has a rounded cut on the lower and upper receiver.
Once you have found a good DPMS generation 1 pattern AR-308 upper receiver, the next question is figuring out whether your rifle requires the high profile or the low profile upper receiver. The difference can be seen in the image below.
Generally, users use the low profile version for their builds, however the high profile uppers will still work. Low profiles are often used because they look more aesthetically pleasing.
When it comes to the lower parts kit, most AR-15 parts will work, but there are a few exceptions. The bolt catch for the AR-308 is larger and has a threaded pin, instead of a roll pin. In addition, the pivot and take down pins are also a different size. Below you can find various parts kits that are compatible with our AR-308 DPMS generation 1 lowers. Custom AR-15 triggers and pistol grips also work with the AR-308.
Below, you can find a list of suppliers that we and our customers have used to great satisfaction.
Palmetto State Armory
https://palmettostatearmory.com/ar-10.html (Despite the AR-10 designation, the upper receivers are still DPMS generation 1.)
Delta Team Tactical
As always, if you have any questions about parts and compatibility, call us directly at 512-584-8013 (Option 1 for Sales) or email us at email@example.com.