Got the mold last week...great mold. Had a pot of Lyman #2 in a Mold Master XX I was using and couldn't resist. Mold preheated to 425, melt at 750. Only took a few casts to get good bullets. Casting speed put them just on the edge of frosty. OAL of 3.3 as designed. Cast at .462 sized to .460 as expected from #2. First group from a clean gun is picture No. 1 in the diamond. The group under it is round after 40 rounds without cleaning (I forgot the cleaning gear). I was shooting other cast bullets and only loaded 10 of the 28 grain of 2400 for around 1300 with the MM550460. The second picture is 37.5 grains of AA 5744 for around 1500 fps. I'll cronograph when I get the best loads worked out. For a stouter load I'll work with 3031 for around 1900 fps later.
For an out of the gate range session with only 20 rounds loaded, I'm more than happy with the results. I have great hopes for this bullet. The .460 diameter centers the neck, and neck sized brass centers the cartridge. The 1.3 inch length has the bullet still in the case as the front band centers in the freebore. All that with the .451 bore riding nose and I think I've got a winner. Another project for the summer.
Thanks again for a great mold.