Thank you for all the informations
So, according to H. Dumoulin from Belgium, the .500 Jeffery has problem with feeding cartridges in barrel (rebadet rim)the .505 Gibbs has not problem. The .500 Jeffery is just more power that the .505 Gibbs, but it is not significant.
The most important in the situation is that when you are a
little range of the animal (elephant, buffalo, hippo)your
rifle doesn't jam. A possible problem with the .500 Jeffery.
Question, Why not use a double riffle in .500 N.E. ?
We have 2 quickly shots available! with a bolt action is
impossible I think !
At soon.