Kinda' sorta'. .264-.303. or 6.5-.303. I found out it actually had been done before ... in Europe, of course. Impossible to find load data for. A .25-.303 was reasonably common and there is some load data for it, so that's where I started. Long story of how it happened. I was looking for a .303. I actually wanted a No. 5 Mark 1, but would settle for a no. 4. Very good friend of mine (shop foreman at Champlin Firearms at the time) made a lot of gun shows and he was looking for me at the same time I was. Well, of course, we each found and bought one. I had always wanted to play with a 6.5 and had access to a machine shop with lots of nice equipment at the time. The same friend came up with a .264 barrel for me and I went to work. Long story short, it was pretty crude, but I got 'er done. I had access to a nice little CNC lathe and cut my reamer out of aluminum to 'perfect' the design (nothing perfect about it). I broke the first (best) hardened reamer I made, and had to make a second one. It was not as good as the first, and I wound up with kind of a secondary shoulder. Of course, I had to make my own loading dies as well. Anyway, I finished the rifle (never blued the barrel), worked up some loads and killed one deer with it. That's been many years ago, and it might not have been out of the safe since. I was actually taking a Vo-Tech machine shop class at the time, so I was a total novice.
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