I think it's the ammo as much as anything. The load I'm running with seems to work well with all of my 7.62 battle rifles. It's 40.8 gr of Varget with 168 grain AMAXs or SMKs. The brass is Lake City once fired. The ammo is loaded using a Forster full length resizing die and a Forster Micrometer seater die which together produce an extremely concentric and; thus, accurate final loaded round. Out of my DPMS Gen Recon's 16" barrel, I average about 2323 fps and that rifle shoots less than 1/2" at 100 yards when I'm doing everything right. Groups open up to about 1" with the suppressor. From MY AR10T's 24" barrel, this load leaves the muzzle at about 2,567 fps. I haven't chronied it on the FAL yet but I will soon.
The scope on the FAL is a Nikon 2.5-10x44mm Monarch X which used to sit on the AR10t. I have read that FALs beat the Shiite out of scopes. Since mounting the scope to mine, I haven't put enough rounds through it to notice but I'll probably switch to a Vortex for the lifetime warranty services just to be safe.
Here's the rifle:
The FAL is a fantastic rifle IMO. I would never get rid of mine. 60+ years old and it's still hard to beat the platform.
The AR10 is a fun gun and I like mine but the platform just hasn't earned its stripes the way the FAL has.