Any old peep sight users out there? All I could find is the Lyman in midsouth for $48. Does it lock in when set? and how durable is it. Figured some of you guys might have had them on your levers. I need one for my Browning 71 (win1886).. Not afraid to spend a little more for a good one but some of the ones I've seen for the Sharps and the like are a little steep.