I made it to the range today with my chronograph. Unfortunately I only got to check 8 shots before the chronograph died, apparently it doesn't like the cold. The load I got to check was a 230gn fmj with 11.0gn Long shot and loaded to 1.250" oal. I used CCI large pistol primers, and I think the primers will be the limitation with this round. This was right in the middle of the load range, and clocked at about 1310fps (1290-1339, 1311 avg, 14 SD). I had some loaded with 11.7gn (max is listed as 12.0) and found a few pierced primers plus some that had the dent from the firing pin pushed back out. The cases have a slight bulge where the feed ramp is too. I took some videos and am just waiting for them to upload to YouTube. It wasn't a very good day to be shooting for groups, as it was -19 with a -28 wind chill today. I did put about 50 rounds on a target at 25m, but I had already been out there for almost two hours, so its not exactly impressive. I was shooting at some 8"dia steel plates earlier, and hitting them about 6 or 7 times per mag, and about the same with the other 1911 that I brought along in 45 acp. After shooting the two of them back to back, I can say the 460 definitely has more recoil than the 45acp, but nothing unmanageable. I put about 200 rounds through it today without a beaver tail and my hands were fine other than the cold. I wasn't wearing any gloves while shooting. I would rather shoot the 460 with heavy loads than my 6" S&W 66-1 with heavy loads. Here's a picture of my lousy shooting today. The squares are 1".
Here's a picture of some of the brass. Top is a pierced primer, next two are also pretty over pressure, bottom aren't too terrible. Most were better than this. It doesn't really show up in the pictures, but you can see the cutout where the extractor is on each one is slightly raised.