The 243win my kids use has either has a brake or suppressor on it when they’ve shot it.
This was my thought as well.If he likes the RA 223 why not get one in 6.5 Grendal or 6mm ARC? Seems simple. Those are new calibers but with ARs being so popular I suspect ammo availability might beat the 243.
Nothing against either of those calibers. Personal preference to stick with legacy chamberings.This was my thought as well.
I had a RA Gen 2 with the 20” barrel in 6 ARC and had very mild recoil.
Down side is that it did have a brake, but I don’t think it would increase significantly with out it.
ETA. I know the RA doesn’t meet your requirements, I was referring to cartridge.
I'm currently cutting down a rokstok and adding spacers to fit for my 7 year old, to get him his own bolt gun for Christmas. He currently shoots a 17 MACH 2 Ruger 10/22 that I built for him.
A stainless Tikka .223 barreled action, chopped to 16" and threaded with a suppressor will go into it. He's going to be shooting reduced load 62 grain ELDVTs for practice and varmints/predators.
Nothing he won't be able to kill with that gun when he's old enough to hunt big game and step up to the 77 TMK.