CptCurl,
On 12/02/08 at 0736 he wrote "Hopefully the extra 20 grains of your 460 grain bullets will not make a significant difference, otherwise they will want to shoot slightly apart." That's a couple of lines before your quote above. In theory I agree, the heavier bullets will shoot apart but in practice the rifle is being asked to shoot a heavier bullet than it was designed to shoot. Would it work? Possibly, but Pistolchamp will probably find a regulating load faster using a lighter bullet. In my two 500s I use 340 & 375 gr bullets over 53 & 54 gr of 4198 with 13 gr of dacron with excellent results. I've also spent the better part of two months helping a guy reassemble a nice double after he fired it using loads that were far too hot, splitting the stock and bending the tang, trigger plate and parts of the locks.
On another note I'm interested to hear about your success using paper patched handgun bullets. I tried some about a year ago with fair success but haven't had time to do more with the idea. I did find that the patchs wanted to slip on the bullets until I rolled the bullets over a course file before patching. Another avenue to explore when time permits.
Have a good one.