I can answer that question as the topic comes up when prospective shoppers are looking at the options .
OEM 5 rd + dummy extension - 9.8 oz
7 rd FFT Ti tube 5.6 oz
One of my 7 rd thin wall 4130 steel tube 8.8 oz
I don't have a weight on the OEM 7 rd steel, but likely heaver that mine
after you load them all up with OO buck you will not likely notice the difference.
Joe B
Stamp came back. Very handy setup! Started as a 11721 LE, and now maintain the option to switch back easily with the 18.5" barrel and OEM magazine extension. Also shown with B&T handguard and EOTech.