CDNN still has some new old stock Marlin X7S in .243win. $249.
You can sell the Axis sporter, and be way ahead.
The X7S I had was excellent. Better stock than Axis.
I sold the Marlin to a friend for grandson. He's crazy about the rifle.
I replaced the Marlin with an Axis. Couldn't stand it, though it was just as accurate as the Marlin.
If you can't get a ground hog at 350yds with a scoped .223, you need to sell your rifles and get a Mossberg M500 shotgun and stick with shooting squirrels at 50ft.
I shoot 3" groups at 300yds with my RRA NM AR.
With IRON SIGHTS... and I'm 62yrs old.
Instead of spending $$$ on gun mods, I suggest a good laser range finder, better rifle scope, handloads, and most of all, range time... and maybe a ballistic app for your phone.