Perfesser,
Are you planning on using that Grease wagon in a percussion revolver?
If so the main problem is that it is only Ø.358 in diameter, you're going to need a Ø.375 to Ø.380 to use it as a traditionally inserted bullet. I guess you could patch it.
I know the average volumes of my Uberti Navy chambers and with a bullet the length of the grease wagon with 1/16" compression and 1/16" below the cylinder face (notice those two cancel each other out). You will get 0.72ccs to 0.75ccs of powder space. Lee Does have a 0.7cc dipper that they say will dip 11.1gr of FFFg, So I would say you could get 11.5gr under that length bullet. With a different Nose profile we can get you more powder.
Another problem is that the bullet is so long it won't even fit in the loading clearance on my 1861 Navy models. The bullet is not a heeled bullet with that rebated section (which also makes it almost impossible to start). That is the problem I have with the traditional pointed conical bullets, they are hard to start.
Now, if you wanted a 160gr Heeled bullet with an ogive like the 38-135C I can draw it up for you (for a cheeseburger...) and you can send it to Tom at Accurate. He makes all of his molds from CNC programs and each can be unique. In fact when I get a .45 PRS replacement mold I'm going to get it as a 4 cavity and have two of them be a 250gr .45 and the other two the EPP-UG .45 style for my Cap guns. I won't shoot very many of either and I'll just cast the both at the same time. He will do that for anyone.
But, seriously I know you reported you have the 250gr .45 PRS and the 2oo gr version. and will trade you a design you can send Tom for some dimensions. (I was going through all of the boxes we still have stored in my 32 x 60 building and I can't find the few PRS .45 bullets i have squirreled away somewhere). I'll attach a drawing with dimensions I need and if you have a caliper that would be close enough measurements since I have to massage them a bit anyway.
In fact if you wanted a Grease Wagon, you could also have your 160gr (or more if you wanted it) on the same mold. He might do a 4 of one and then the other on a 5 cavity, I've never asked.
~Mako