Smo if you want to save $ to spend on fodder ,Walmart has (had) a millet one piece ,that I can use on different rifles . It does not change zero ,when removed and replaced. I was shocked! I got it on a whim to scope a muzzle loader. I have always used 2 piece . And could not believe ,a 1 piece with 1 clamp (1nut)could be repeatable . Using 30mmtube have not tried 1"! They don't seem to be able to keep them on the shelf though. Too late I see, meh!