Anyone finding that the RIP TKO's are brittle? I've shot VAP TKO's the past 3 yrs and been very impressed with how they hold up. But was shooting 75yrds and I dropped 2 RIP TKO's low that just missed under the target. I realized that the sight was still dialed to 70yrds. They hit a rock about the size of a fist, and broke off behind the insert. I never had that with the VAP TKO's. Anyone had similar results?