I have had a Lead Sled for about four years. I use it for working up loads and with the chronograph and do not put weights on it. I think it has the potential to damage stocks and I had a scope move in my Talley QD rings once and wonder if repeated use might damage a scopes internals.
I much prefer bags and/or the Caldwell Rock BR over the Lead Sled and can never get comfortable with a Lead Sled and shoot better groups with bags.
My 8 lb. custom .338 and a customized 7 lb. Marlin 1895 in 45-70 are my worst kickers with their heavy hunting loads. But, since I have had loads for them for many years I should just sell the Lead Sled.
