I've shot a lot of Remington 165gr soft point flat base bullets through a Britishicon FAL barrel on an Imbel upper receiver. I found it liked a moderate charge of IMR4895 and Winchester primers. Varget has never been a lucky powder for me.

I did shoot a number of reduced range US NRA National Match courses with it. It could shoot about 3.5 MOA. It did not seem sensitive to sling tension. For awhile I fitted it with a US hooded rear sight aperture, but that did not help much.

A lot of these rifles are really hard on the case rims. Shoot yours some to see if it bends case rims back on extraction. If it does, polish your chamber, use a smaller gas piston, and a stronger gas piston spring, as well as set your gas relief valve on the most open setting that will reliably function. A faster powder might also help, but I haven't tried that yet.