Al in Mi,
I'm not sure where I got them, I usually keep some around if I can. You just have to buy them wherever you can. My first pair came from Bauska in Montana and were rifled with a .600 Nitro Express rifling button. Those cost me around $200.00 each and a years wait. Deffinately not worth it! I will do some checking and when I find out who made them, I'll let you know in a P.M.