hey guys, so I just got my bcm upper (with barrel installed) in the mail a few days back (happy!) and I'm having trouble getting the handguard installed on it. this is my first build so I'm probably just doing something wrong. I can't seem to slide the handguard on. seems its catching on the grove near the barrel nut. do I just need to manhandle the sucker on? I tried to get some pictures.. but lighting isn't great. Take a look and any advice would be greatly appreciated.