For a HUNTING sight, a vernier is not what you want. Way too slow and too fragile. The very best hunting sight comes on your Shiloh. It is the barrel buck horn sight and blade front. If you have trouble seeing the blade, get glasses that allow you to see it. Correlate the sight ladder with a laser rangefinder. TRULY learn to use the ladder barrel sight, and you can reach from the end of your barrel to as far as you can see. Remember this: buffalo were killed by the millions with Sharps rifles and BARREL SIGHTS by men who knew how to use them. I'm not blowing smoke, I've hunted with a Sharps for years with barrel sights and traditional ammunition. Don't handicap yourself with a vernier for hunting.
