Would a 6.5 creed be ok threading that has outside diameter of .55-.56. it's a savage 110 storm. My 7 year old is an awesome shot and I don't want him to develop a flinch so want to put a brake on it so he can hunt. He has been shooting a 17hmr the past year. 3/4" groups up to 70 yards and at 100 about 1.5" 5 shot groups if it's not windy. He's been in a 4X6 blind with me shooting a 300wsm with a 4 port brake, the blast does not bother him.

I know you already have the Savage but I would look for a Ruger American Predator in 6.5 Grendel or 6.5 Creedmoor. Both already threaded, light weight and solid platform.

Most sporter barrels get a 1/2" or 9/16" threading for a brake, with 9/16" being most common. But it depends on what the outside diameter is of the muzzle. Threading it for a brake is fine, it will help reduce recoil, for sure.

Outside diameter is .55-.56

Let’s be honest, those groups with the .17hmr are pretty mediocre, first thing to find out is if it’s the gun or the shooter. Next, putting up with the blast from a .300 wsm while sitting in a blind has nothing to do with being able to shoot one. The key phrase here is; “I don’t want him to develope....” you should be asking your son what HE wants to develope.

1/2-28 (1/2" 28 T.P.I)

P-102 I'm only trying to set him up for success. He wants to shoot a deer, hog, or nilgai this year. And he has earned it. As far as his groups being mediocre, yes they are I guess but for a seven year old I think it's damn good and he's just a good shot, he has no flinch, the kid doesn't even blink and very consistent. But if he can't shoot the same or damn close as with that 17hmr then he won't be hunting, and shots will be limited to 80 yards. Some people actually have a harder time dealing with the blast & concussion from a brake than recoil so that is significant that it doesn't bother him.

Does he want to shoot a deer, hog or nilgai this year because that’s what HE wants or because that’s what Daddy would want him to do?
7 years old is old enough to shoot much better with a .17hmr if the rifle is capable....sit down ant talk WITH him about what he wants.

Sage advise.

That sounds like pretty good shooting for a 7 year old. I don't see the problem here.

I've never pushed him to..he can keep tagging along and I'll do the shooting but last year he kept asking me when he'll get to. So I told him this year if he can shoot a "deer rifle" well enough and understands the vitals and shot placement. I'm perfectly fine with him waiting, but if he's capable and takes the time to learn then he can. I have have asked him a many times and his answer is always yes..not just asked him but actually talked. My wife too. I think its a big deal deal to take an animals life and would never pressure him to do that. Plus he loves the meat and helps me skin and process. I didn't just wake up yesterday and say to myself my kid is shooting a deer this year. We have been talking it over for a few years now. He's been joining me since he was 3 because he wants to. Thanks for the concern but I really don't see where your going with this p102.