Lightweight build:
Barrel assembly is a DD 16" LW CHF and A1 receiver is from Fulton. To zero at 25m I had to dial the front sight so far down, it might be bottomed out. Is this an issue from using an A1 upper and an FSB meant for a flat-top upper? Does anyone make a short front sight post? I think something like 2 mm or more needs to be taken off the top of the post for it to be at base height.
https://www.m4carbine.net/showthread.php?t=70448
I remember coming across that recently. The difference between FSBs shouldn’t be that huge. If it bothers you, you could always just file off a bit of your sight post.
Yes, your issue is the F marked FSB. I don’t think they make a short one. Disregard my idea of shortening the threads. I just remembered that’s not where it’s bottoming out.
Also a 100 yard Zero is all around better . Sweet carbine!!! That is how I like them!
Are the rounds striking high or low?
Rounds were striking high. It’s zero’d now at 1" below POA at 25 yards, but the post is all the way down. This annoys me because if it needs more downward adjustment when I try it at 200 and 300, I will be out of luck.