As an original owner of a Bren Ten (Special Forces model), I certainly understand your dilemma. To make matters even more difficult, the Bren Ten is a delightful shooter, reliable, accurate, and with the sweetest DA/SA trigger ever put in a handgun (Sig and Beretta are good, just not as good). I share your concerns though, and only take mine out to the range every year or two. But RecoilRob's observation is correct--- early Norma 10mm ammo was hot (over 600 ftlbs). Today's 180g Federal FMJ is advertised as 1030fps (I've chrono'd it at just under that) and that makes for a muzzle energy of 425ftlbs. You won't kill any wild boars with that load, but it shouldn't kill your prized Bren, either. Enjoy!