Will the A2 competition front sight from Bushmaster (.052 inches)line up with an ARMS#40 rear sight mounted on standard A3 flattop upper with the ARMS #45 system? I hope this makes sense. I was wondering if I need to purchase the front sight for colt uppers which is suppose to match up with the ARMS#40 rear sight.

Thanks in advance,
Leadfoot

All I can say is to try it, and if it doesn't work, get the taller sight post. Not much help, huh? I had a Dissipator which worked fine with a standard front post & #40 rear sight, but when I switched to an M4 barrel, I had to elevate the front sight uncomfortably high to zero @ 50 yds.

Thanks Zardoz for the reply. I purchased the the thinner .052 sight from Bushmaster but I never zeroed the sight with the iron sight just with my aimpoint. So now I'm about to place another order with Bushmaster for one of their newer heaver bolt and carrier assemblies and I was thinking about getting the higher sight post.

I like the thinner sight because I figure it would work better at longer distances but I haven't had a change to test the sights at a range greater then 25m so it's hard to judge if I need the taller post.

Leadfoot

Leadfoot, I know the Colt front sight post is thinner as well as taller (to give the M4 the same sight picture as the M16A2). I haven't bought the Bushmaster product so I can't say; but as Zardoz said, your current sight may work fine.

Thanks for the reply BR. I'll probably go ahead and buy the colt sight for $5. I just didn't want to go through the hassle of resighting my rifle. I didn't spend a lot of time sighting the rifle in with the irons but focused on my aimpoint. Now I will have to go through the process over again when I replace the sight with the colt version. But it just gives me another reason to take my guns out for some more fun.