After watching Brett Gibbons making pritchett base plugs out of magic sculpt epoxy putty, I wondered if the Pritchett concept could be scaled down successfully. I have a unmentionable 50 caliber rifle I bought to experiment with so I ordered a Lee 50 cal minie' mold. Those cast out at about .502", so I sized them down to .484" and after patching they came out at .490". I made base plugs by rolling the epoxy into approximately a 1/4 inch ball, and flattened it with the nose of the bullet. They fit into the base cavity nicely and I let them cure overnight. This morning I dip lubed them in Gatofeo #1 lube and proceeded to shoot. After 20 rounds at 75 yards, I had a group about 2 inches across. No fliers, and every round loaded easily with no trouble. So, I am convinced the Pritchett concept can be used in rifles other than .577 and it works extremely well. I have what is essentially a caseless 50-70 with decent accuracy and quite fast followup shots. I was going to order a custom mould for this, and may yet do that but for the time being this simple Lee mould will do the trick.