I recently built an PSA AR and turned out great.
At first I mounted a Vortex Sparc red dot and decided I wanted to try a magnifier.So I got a Primary Arms 6x with flip to side mount set up for lower 1/3.

Now when I just had the Vortex my groupings and shot placement was pretty good for me at 100yds.I then added the magnifier and of course needed to re-zero the red dot since I had to move it a bit further down to make room for the magnifier.
Well this time at range my shots were not as well placed nor were my groupings as good as the last 3 times with just the red dot and both times using a bipod.After looking over the rifle I noticed that my red dot just slightly goes over the bridging of the upper and the free float rail.
Could this be causing an issue? Should I not let it bridge over the 2 at all? Then again I could have just been having a bad day at the range,been sick so I havent been back to verify yet.

Pics to help show.

http://img.photobucket.com/albums/v209/rabidscoobie/20141024_142833_zpsa7cf8080.jpg

http://img.photobucket.com/albums/v209/rabidscoobie/20141024_142805_zps89644aa2.jpg

http://img.photobucket.com/albums/v209/rabidscoobie/20141024_143000_zps091e9583.jpg

Sorry guys I cant seem to get the pics to show up in the post,just links.I normally do not have an issue posting pics in forums but for some reason I cant do it here.
Any input on that issue would be nice as well.

No...ideally you don't want an optic sitting on both the upper receiver rail and the handgaurd rail.

Thanks thats what I figured.
Anyone one know of a similar mount to the Fortis F1 that might be a lil cheaper? I think something like that might give me just the space I need.I just dont know if I want to spend $75+ for that one.

I would just remove the buis sights and slide everything else back a notch...done.  That or shuck out some more change for another mount.

Reality is you are likely never going to use the irons on that set-up, and I am well versed in the "better to have it and not need it" deal.

Thanks everyone.
Yeah I would but I do have the mag on a QD mount and I do from time to time take it off and use BUIS for fun and keeping practice.
Honestly the only reason Im not sure about the mount or spending that much is if thats not the issue and I just shoot worse with the mag then I'll remove the mag and go back to the red dot,then that mount would be a waste.But Im sure the issue is with bridging over between the two upper halves.

I know that you should not span the gap with the sight.  That being said, lay a metal ruler along the rail and the receiver and see if they perfectly match up.  If not then loosen the handguard, torque the sight in place and retighten the handguard.  Only problem is if you should ever do something that twists the handguard then your red dot could be thrown off again.

Make sure the link for the pic has code [ img ][ /img ] at the beginning and end. No spaces in the code or at the link.

Thx all for the help.
Thank you for the pic info also.

Well I thought I would try something out with a different mount that looks just like the one that came with my Sparc from a friend that didnt want it anymore.
What I did was trim the front lower part of the off with a dremel,I mean we are talking only a quarter of an inch at most and Im sure its not even that.I did this so that the mount doesnt not actually touch the hand rail at all.I will go out and throw some lead down range and see if that resolves my issue,if so I'll just grab the Fortis F1 and be happy.
I could prob just keep it with the modded mount but I just dont like having anything that looks like Billy Bob did on my firearms.

I thought of trying the method of loosening the rail,tighten the mount then the rail but this rail does not stay %100 squared with the barrel.The end of the hand guard is just slightly off towards the end,maybe my whole issue.I had it looked at and was told it was normal.Its just with the BUIS I have to adjust windage for the offset.

Also I forgot to mention that this is my first AR ever,I hadnt even fired one before this.So I am in a lerning stage with this as to the do's and dont's.Loving it so far.

Thanks again,
Mark

I tried the img tags and even used the forum editor to insert links and all I get are the red links....
When I do a preview it shows the pics.