I agree with Andy.

First, you should decide if you want an inch or metric receiver. The basic inch receiver has some pretty significant improvements over the basic metric receiver. It's more difficult to find parts for inch rifles in this country, but they can still be found and they cost a cost a bit more. This includes magazines. It's fairly simple to outfit a metric receiver with the improvements found on an inch rifle.

For someone that isn't familiar with FALs ( like me ) you can easily become overwhelmed with the amount of information out there. There have been rifles produced for so many countries, and that means there are tons of different variations of the same rifle. It's a lot of information to take in.

I went with a complete rifle built on a metric Imbel receiver. The receiver and bolt have been machined and outfitted with the inch improvements. It's not perfect, but for me it is easier and cheaper to change the things I want changed than it would've been for me to build the entire rifle. So, I have a rifle for which parts are inexpensive and readily available, and it has all of the improvements of an inch rifle.

Back to the Ruger GSR. Have you looked at the Mossberg MVP Patrol chambered in .308? I have an old Remington 788 Carbine that fills that role very well, but the magazines are proprietary and no longer produced. I've been looking at the Mossberg very hard.