I have a 6br using 10 round AICS mags and I am having difficulty with reliable feeding. Mainly using 107gr. The last three rounds seem to nose dive in magazine, the bolt rides over the case head and does not pick up the round. I've seen the video clip and guide by Dave Bergen. Has anyone out there actually got this mod to work? If you have please give me more details of how you modified the mags? When compressed the spring is almost the full width of the magazine so how did you get it to work with the front spacer? Any pictures or more advice anyone who has done this can give me will be much appreciated. I've pm'd DB but not had a reply - is he still a forum member?