Hi folks,

I've got a CMMG upper with an 'F' marked front sight base, and just picked up a YHM flip-up rear back-up iron sight. I don't know much about the 'F' marked front sight assembly, but I understand it's a bit higher than the 'standard' A2 front sight assembly.

That said:

Will I have any problems using the YHM rear flip-sight with the higher front sight base ?

What is the 'set zero' for the YHM rear sight (it has no ability to adjust elevation, so I am curios if it is set at 100 meters, 200 meters, 300 meters, or something else alltogether) ?

Thanks in advance for the help.

There should not be a problem with the flip-up BUIS and the 'F' FSB.  The 'F' FSB is for the flattop recievers, and the flip-up rear are made to go on the flattops.

Thanks for the info.

Anyone know what the 'default' range is for that flip rear sight ?

You will be good to go , i have a YHM BUIS  on my bushmaster and i have the F marked front sight post ..

Quoted: You will be good to go , i have a YHM BUIS  on my bushmaster and i have the F marked front sight post ..

Just curious before I get it out to the range - did you have to crank down the front sight post quite a bit to get it to sight in properly ?