Comments for the 3 Ring 54 Caliber.
MM-389/440 - I don't have one but I do believe they are the same bullet or very dang close to being the same.
MM-412 - I can see this being the same or a variant of the MM-439 Vicksburg Rifle but I can't go along with the MM-411 being the same.
MM-413 - another bullet known as and associated with Georgia Troops. The size variations are tremendous in this bullet. I have one that measures at 1.091 in length.
MM-415 - listed as an Austrian in the MM and I can only speculate the name was given due to the close appearance to the MM-320/321/448.
MM-417 - I don't have one and haven't seen a 54 caliber with a plug nose that distinctive. The bullets been fired, stepped on, and who knows what else so the identification is a tough one. Anyone have a close resemblance of one in their collection?
MM-418/419 - For years known as a Selma Arsenal. Compare these to the MM-476/T&T 144.5/Stelma 06-217 as well as the notes on page 186. Same bullet as the MM-418/419 apparently poured without the base plug. I have seen a couple of fired specimens but not many. Jim would you comment on the MM-418/419 since yall found no documentation in Selma for the RBTRF IV.
MM-420 - I consider this bullet the 54 Caliber version of the MM-384 as listed in the MM notes. I believe the cavity may have been misidentified.
MM-421 - does anyone have this bullet with the length as long as MM states at 1.105. If they have a spare I would be willing to purchase one.
MM-431 - this bullet is not a salvaged lead/Richmond Arsenal (Lehner/White) bullet. This is a very rough bullet with lots of ground action and the patina worn off.
MM-453 - as Wes noted has been known as a sharpshooter bullet. Okay I go out on the limb on this bullet all the time and catch a lot of flak because I believe it is a 54 caliber version/variant of the Texas Troops/Cove Creek Minie. I have no documentation but just a very strong belief on this.
MM-460 - I had not heard this bullet being mainly a Port Hudson and Mississippi found bullet. I can go along with that because mine came from Grenada, MS. I would love to hear from anyone else that has information on this bullet and dig locations.
It's late and again I have just gotten off of work and added these comments to the 54 Calibers. I will cover the MM-500/600 series after some sleep.
Any of the leadheads or anyone else jump in and add comments/agreements/disagreements/etc.