[ny32182]

I have Troy front and rear, and I just about had to bottom out the front to get it on target at 100yd with Q3131. I expect it probably has something to do with using sights designed for an AR15 height-over-bore, on an XCR where that dimension doesn't match.

Just remember they are called "Back Up Iron Sights" for a reason... and they will serve that purpose fine. I think the standard recommendation is going to be to get a red dot or other optic as a primary sight.

 

[ny32182]

But both sights are rail mount, so the position of the sight line on an M-16 isn't an issue, right? Is the nominal height of the sight line, above the rail, not more or less standardized for flat-top AR-15'sh rifles?

I wouldn't think so... think about an extreme case. Say the sights were a foot over the bore. Think about how far you would have to lower the front to get it on target at 25, or 100yd or whatever.... it would be well past impossible.

I believe the XCR places the sights a little higher than an M4 flat top type rifle. It stands to reason that you will have to adjust the front further down to get on target than you do on an M4.

 

[ny32182]

2MOA per click? I don't know about the rest, but that number at least, sounds way high to me...