Rail mounted sight accuracy

[atomd]

Just talking FSB versus rail mounted iron sights.

For the last few years I've noticed the trend for the AR is long rails, some kind of optic, and flip up BUIS. So obviously the FSB started to lose some popularity. I can understand not wanting it if you have an acog/aimpoint/eotech on there. That's why they make the flip up buis anyways. I've set up a couple rifles like that myself and I liked them.

What I've noticed more recently is lots of pics of guns that have iron sights as the primary sight but they have fixed sights attached to long rails. I guess I get the point of maybe a longer sight radius but the front sight pinned to the barrel seems like it would be more accurate under most conditions and the sturdiness of the fsb has got to be hard to beat. But then again you now have a free floating rail so a sling or other things making contact indirectly with the barrel will now not be a factor.

I'd like to see some real world tests of rail mounted sight accuracy versus fsb. I've practiced with my buis on a few guns and it was fine as far as practical accuracy but I've never been able to do any real head to head accuracy tests since the setup of the ar was drastically different from the one with the fsb.

Anyone ever tested this? I've seen plenty of theories about it but never a real test with the same variables.

 

[gunnutery]

I haven't researched it, but I doubt there's really any measurable difference, as long as the rail is solidly installed.

One thing you don't see a lot of is forward mounted optics though. I've inquired about that before and IIRC, people didn't want to risk having a slight movement of the rail. Personally, I've never been that picky and would consider mounting a RDS on the railed forearm.

Back to your sights though, I agree that the fixed rail mounted sights are only adding sight radius. If someone wanted an all-time co-witness that's fine, but I'd prefer not to complicate matters and go for flippy sights.

 

[wally]

One thing you don't see a lot of is forward mounted optics though.

What you don't want is the optic spanning the rails with one ring on the handguard part the other on the receiver part -- this will stress the scope if the handguard rail moves.

A red dot with a single "ring" either will be fine unless the handguard is sloppy.