A normal 18.5 inch standard profile carbine barrel is around 29 oz. Replace with a lightweight aluminum bull barrel in the same length and it is around 19 oz. Go to a 16.5 inch and the weight savings is greater. A carbon fiber barrel will get you down even more. Seems that the only other way to save weight would be in the stock and scope (if used). A fixed power scope is usually lighter than a variable power.
See Whistlepig lightweight barrels at https://www.wpgbc.com/
Magpul Hunter X22 stock is a lighter stock option, has a barrel channel that is reversible for either standard profile or bull barrel, or remove the barrel channel entirely for most weight savings. See at https://www.brownells.com/rifle-part...prod79484.aspx
Brownells has a sale today at 15% off and free shipping which brings it down to less than Midway's or amazon's price.