No brakes. No good reason except that most of the guns were purchased before my defection with extreme prejudice from NY State. My approach to recoil modification is to shoot chamberings with a reasonable degree of recoil to begin with, and to shoot lighter bullets in rifles that are not intended for usage at extended distances.
All of my AR and target gun barrel contours are either Bull or HBAR, except for the lightweight one, which is slim with an A2 Hider and is one of the two purchased since the move to Arizona. The 7.62x39 Scout and .223 MVP Predator are lightweight/medium fluted bull with basic hunter barrel crowns.
I shoot .223 up to .30-06. The Axis II .30-06 hunter has the most recoil. As time permits, I'll be developing a dedicated Nosler 125gr Ballistic Tip reduced recoil load for it. I have scads of them left over from the defunct 30BR project. They will also eventually go into a load for the 7.62x39 Scout (it has a 308 bore).
BTW, I haven't been a kid for at least 50 years, and the last part of that 'being a kid' was as a Draftee Marine in Quang Tri Province. Got out on Feb 22, 1968, turned 22 that following May 22. First serious rifle I had was a Deuce Rem 722, too. Cleaned the target with it in the first Carlos.
Greg