Read this taken from Mr. Taffin's page:
500 LINEBAUGH LONG/MAXIMUM: We have arrived! There is simply no way to get any more power into a sixgun that can be packed easily on the hip or in a shoulder holster. Perhaps more importantly, there is no way any of us could handle any more felt recoil. It takes everything I've got to muster up the concentration and strength to handle this Monster Maximum.
The .500 Linebaugh Long, again named for its creator John Linebaugh is a 1.610" in length fifty caliber cartridge made from .348 Winchester brass. It can be loaded with the same dies used for the .500 Linebaugh and thrives on the same bullets. However, while the .500 Linebaugh is somewhat sluggish as to muzzle velocities, the .500 Maximum is quite the contrary. The .500 Linebaugh Long/Maximum will max out with a 440 grain bullet at 1550 feet per second! That is a rating of 50 on the Taylor Knockout Formula and believe me one feels knocked out on the back end.
Felt recoil is S-E-R-I-O-U-S to say the least. I find I must use a padded shooting glove such as the Chimere and also tape the tip of my trigger finger and pad the knuckle on my trigger finger to shoot the biggest .500. Even then it takes a tremendous amount of concentration and expended strength to handle the .500 Maximum and the .475 Maximum for that matter.
All I have to say is GD that sounds like a monster!