I have an Aimpoint PRO and a PA 5x Magnifier on a Flat Top Spikes Tactical Rifle. I do not have enough room for everything on the receiver and I was wondering if it was a bad idea to have the Aimpoint straddling the area between the receiver and the FF rail?

It doesn’t seem like it would be a problem since it is a flat top, but I just wanted to see if I would be causing any undue stress to the optic/mount by doing so.

Thanks in advance!

what kind of rail?  is it continuous with the upper?

It is the spikes tactical SAR rail (12").  It is continuous with the upper as far as alignment goes, but as it was not milled from the same piece of metal, I was concerned about flex issues....ie the mount not allowing the flex to occur, or the flex occuring and damaging the mount.

Nope, it should be avoided. I am not fond of the idea of mounting an optic just on the rail either, though with solid rails it is fine. Bridging is a no no.

Edit- It can hang over a hair if that's what you mean.  Just make sure it doesn't touch the rail.