So, went to sight in my Sig 556 classic today. Set up at 25 yards with the typical M4 zero target. Was firing from a seated position, using the magazine and gripping around the magazine well. Initially, 2-3 shot groups were both to the left significantly. So, I put on the expected dope and brought it right no problem. It was also a bit high... so I then adjusted the rear sight drum (sights were on 300 the whole time, this was the drum sight) for elevation.
I came down about 7 clicks. Fired another 3 shot string. Groups are back at the SAME POINT that I initially started at. As if I'd put no wind at all on...though now, the elevation is correct. Hoping it was a fluke, I fired another 6 shots... All in the same place. Took my rear sight ALL the way to the right and ended up just barely touching the left shoulder of the zero ring. I had to make a front sight adjustment to actually get the last few increments I needed. However, I have no right wind left and my front sight is several millimeters to the left.
Looking from the front, I notice that the picitinny rail on which the rear sight is mounted appears to be slightly canted. Is this typical? If so, what's Sig's track record on fixing it? It would seem to explain the windage changing with an elevation change.
Same issue here
I have to position the front site all the way left and the rear site all the way right to get it at POA. A pain in the arse to send back a $1200.00 gun for something that should have never left the factory. I have to call on Monday for a RMA