ArmaLite AR10A4 Carbine

[Glockrocks]

Question about the ArmaLite AR10A4 Carbine, the model with scope mount is $50 cheaper than the same model without scope mount?
Do these also accept 3rd party mags as well?

Thanks in advance.

[Atlantic Firearms.com]

Glockrocks unfortunately we are sold out of all Armalite rifles at this time