Ah you guys were right, the pins are hollow... not sure how to take them out without damaging theme though.
I found this M4SI handguard rail, and seems to be pretty cool.
http://www.evike.com/product_info.ph...ducts_id=38524
Would my old style TM Delta Ring fit this or would I need to purchase a delta ring with the teeth (btw what do you call the delta rings with teeth?).