Many of you know that there is a huge selection of bullets for a .505 Gibbs, I like cast bullets in most of my big bores for casual plinking and have had a hard time finding suitable bullets for my .505. There are quite a few choices in the .510-.512 range so I decided to try and make a swaging die and try to swage some of these down. I took an old .375 H&H sizing die and drilled a .5" hole thru it (from the top down) and then took a split 5/16" rod and various grades of emery paper/cloth and honed the inside until a .505 Barnes TSX could be pushed thru with minimal effort. I then made a small ram out of a piece of 3/8" brass rod and fitted it to an old sshellholder by grinding a "post" that fit thru the hole in the shellholder (I used a RCBS #27 and had to touch the sides if the rod to fit it)to hold it in place. I believe I could braze the rod to an appropriately sized washer and slide it in and out, but the current set up seems to work OK. I screwed the die in my old RCBS press and pushed two different brands of .511 cast bullets thru the die (one heat treated with gas check, the other lubed), which was suprisingly easy and the bullets came out .5065 - .507. I had to run the gas check bullet thru twice, but that didn't seem too bad to me. Both have flat noses and a flat rended rod worked just fine, round nose designs would cause a bit more work. So, hopefully I have a new source of Gibbs plinking bullets.
I think a shorter die would work just as well and I'll be making one out of 7/8' screw stock this coming week. I'll post some photos if I can get postimage to work.

Nice work, we have .505 cast bullets available in Sweden for model 1867 12,7*44r(a .497 50-70), many size-swages down .510-.515 bullets for better concistancy.

I made another swage die, this one out of a Grade 8 7/8" bolt, only 2" long, made to hold in a vise, place the bullet point first in the die (gas check bullets go in base first), insert a polished down piece of 1/2" brass rod and whack it one time with a small hammer (really a home made wooden mallet). Easier than the first die and quicker, too.