I have a pretty big head and it's a challenge. But I have a lot of stuff in my bucket as well. I have 4 fans, an icomm unit, and an audio amp along with the 12v power supply to drive it all. Plus I added a little hearing assist system that I designed. But I'm still able to fit my head because I removed all the padding except in the top and replaced the rest with very thin black EVA foam all around for lining and for looks. It's a process to put on and off but it fits comfortably when it's on. So even if you don't have a lot of stuff in there, removing the pads should help a lot. I also had trouble with the s trim wanting to come off for the same reason but I glued it all the way around with E6000 to take care of that. I wouldn't trim the opening except as a last resort. Sent from my SM-A546U using Tapatalk