Switchman here is what I'm finding from Hawk and as I posted earlier as far as I know they are the only ones making jacketed bullets for the 510 handguns but I also included the link to the site and a listing of all the 510 bullets both rifle and handgun
http://www.hawkbullets.com/Pricelist.htm.50 cal. (.510 dia.)
Round Nose
350 grains x .035 RN...........$45.00
400 grains x .035 RN...........$48.50
425 grains x .050 RN...........$64.00 c4
500 grains x .035 RN...........$52.00
500 grains x .050 RN...........$68.00
535 grains x .065 RN...........$93.50 c2
550 grains x .050 RN..........$70.50 c3
570 grains x .035 RN..........$57.00 c3
570 grains x .050 RN..........$75.00 c3
570 grains x .065 RN..........$96.00 c3
600 grains x .035 RN..........$59.50
600 grains x .055 RN..........$74.00 c2
Flat Points
350 grains x .025 FP...........$43.00
350 grains x .035 FP...........$44.00
425 grains x .025 FP..........$45.00 c4
450 grains x .025 FP..........$46.00 c4
450 grains x .035 FP...........$42.00
Hollow Points
300 grains x .025 HP...........$42.00
450 grains x .025 HP...........$45.50 c4
Spitzers
500 grains x .035 SPZ.........$70.00
50 BMG (.510 dia.)
Spitzers
700 grains x .035 SPZ.........$83.50
700 grains x .050 SPZ.........$92.00
500 Jeffery (.510 dia.)
Special Schuler Design
535 grains x .035 SCH........$63.00 c3
535 grains x .065 SCH........$95.50 c2
50-110 Winchester (.510)
Flat Points
300 grains x .025 FP..........$46.00
350 grains x .025 FP..........$48.00
450 grains x .035 FP..........$54.50
(Hollow Points and .035" jackets by Special Request)
I've actually cosidered getting some of the 350 and 450gr flat points to try in my 500 Linebaughs, if you decide to try them out let me know what you think. Hope that helps a little more.