Colt 6720 tritium front sight post?

AR/M4 AR Technical Discussion
1

Hi,

I’m about to purchase a a colt 6720 that I plan to use only with iron sights, but I have a question about the front sight post. I plan on adding a meprolight tritium fsp to it but I’m not sure if that setup will fit. I understand the 6720 uses a taller fsp to compensate for the smaller barrel/fsb. Can I still use the meprolight fsp with the 6720 fsb and still have everything line up correctly? I plan on using a carry handle rear sight if that matters.

2

I have some Meps & Trijicon Tritium FSP in my Daniel Defense & other (home-made from Bravo parts) ARs with no sighting problems with vertical adjustment. I don’t know if this helps re: Colt, but my F marked FSB are paired with flat top uppers & the standard FSB is with either A1 or A2 uppers.

The biggest compalint I hear about my front sights is that they are “too wide” making shooting small targets (like a clay pigeon on the ground at 100 yards) more difficult.

Hope this helps.

3

The geometry of the .625 FSB is the same as a .750 FSB.

4

Are the meprolight and trijicon the same width? I was specifically looking for a mepro because it looked thinner than the trijicon. Any experience with xs sights? I liked their small tritium front but the sight looked very wide overall to me.

The 6720 does not use an F marked FSB so I know an F marked FSB is shorter than the one on the 6720. My question is, is standard the height FSP ok to use in a non F marked FSB?

5

I just measured these with a caliper. The XS front AR sight I have with vertical tritium vial is 0.10"wide

The Mep is a little dot and is 0.08" (it’s A1 configuration ) wide, so it’s thinnest, but the dot is smallest.

The other Trijicon with a single dot is 0.10" wide. It’s dot is bigger than the Mep, but it’s a wider sight.

The U.S. NRC (Nuclear Regulatory Commision) mandates how much metal surrounding the tritium vial is required for safety, or so I was told by Trijicon about 12 yrs ago when I was looking for a custom pistol sight that was 0.10", instead of 0.125".

Hope this helps

6

Trijicon specs their front sight post at .09" wide.