You can shim the gap, but you'll want to know how thick a shim you'll need. I recommend using a "feeler gauge" such as can be bought at any automotive store.
No, I'm going to be nice to you now because we'll both have to take up a fortified position together when Melody finds out that I snap-spent $70 as a result of your teasing.
Relationships have to be balanced by give-and-take. You can't have dibs on being the big spoon AND being right all the time. Gotta pick one. Anyone who says otherwise is either lying, or gayer than drinking unicorn spunk.
Add that to the list of reasons you need to get into the suppressor game. That list is now a volume thicker than the unabridged large print version of War & Peace.
That's approximately 3/4 of a mile from the long distance range and directly adjacent to and uphill from last falls shoot location. Same location effectively.
Welcome to the forums and looking forward to seeing you get your rifle running. Post up some FAL pics when you get the chance, most of us are gun whores and rarely meet a gun we don't like.