OK, so despite my advice about putting cheap components on his new S&W M&P15, my friend decided to go on ebay and find the cheapest set of flip up iron sights to put on his ar. he said hes just gonna plink so he couldnt justify the more expensive ones. whatever. He also just put a vortex strikefire on that we sighted in as well.
We started by sighting in the red dot at about 25 yards. (i know 25 yards is not a long enough distance for a good zero but my friend insisted we start there and work our way out) We got it sighted in pretty good, then decided to go for the iron sights. upon looking through the iron sights, we noticed that the red dot was aiming at the base of his front flip up sight post. That was kind of strange. we folded them back up, aimed and shot a few more rounds with the red dot itself, and it was holding a good zero. so…what am i missing. it was so off to the point that there was no way of adjusting for it. it wasnt even in the realm of the sight post or aperture. flipped up, it was aimed below the post on the base. any ideas as to what we were doing wrong? even if we took the red dot off, and tried zeroing the sights, the point of impact would have been dramatically lower than the sights would allow for adjustment. im at a loss. I know we should have done 100 yards but we only had about 70 yards to work with on our friends land between the tree like and the berm we were shooting at. does this have anything to do with lower 1/3 co witness or something? for the record, the M&P has a railed gas block that im 99.9 percent sure is the same height as the flat top rail on the receiver. anything else i might be leaving out? thanks in advance for the help.
There are 2 different mounts for the strikefire. Low for sitting on a carry handle and extra high for mounting on the rail. I’m guessing you have the wrong mount.
I am not positive but i think he has the high mount. ill find out for sure later when he gets home. however, After we zeroed the red dot in at 25 yards, we went back to 50 and adjusted a little more. Im having a hard time understanding i guess, but when we go to line up the iron sights to take a shot, the red dot is now in the dirt. if im aiming the red dot at the center of the target, the sight alignment for the iron sights is above the paper. looking through the iron sights, they seem to run pretty much directly in the center of the scope. I guess we should just start all the way over. take the red dot off, try and sight in the iron sights (if they are even able to be) and then toss the red dot back on and re zero that thing too. thanks for the insight and ill search around with that info in mind and see what i come up with.
Is it possible your front flip sight is made for a lower railed gas block and not a receiver height gas block. If he bought a gas block height front sight more than likely its too tall and needs to be replaced with a receiver height front sight. Would explain why the front sight is too tall.
DING DING DING. I figured it out. thanks to everyones helpful posts, i decided to take MY gas block mounted sight off of my rifle and place it on his rifle and BAM. the red dot lines right up. so now he has to get a rail height gas block mounted front sight. haha. thanks everyone for the help.:happy:
