I've just parted with m Merkel .470, and has been looking into getting one of Peters C-class doubles in .450/.400.

I've read a lot on this forum about caliber choices etc, which has given me second thoughts..

I hunt moose, and some deer in Norway. I will, when my economy allows, hunt elephant. Preferably PAC and tuskless. Hopefully I'll afford a second trip some time later too..
Based on this I found the .400 bore to be the smartest choice.

However.. I've read that quite a few have reloaded their ,450s with lighter bullets and managed a regulation load with them as well. That possibility seem very attractive to me, to hunt elephant with a fully loadet 500grs .45, while practicing and shooting lighter game with a 350-400grs bullet with lighter recoil? Is that a good idea only on paper, or..?

The reason I sold my Merkel was twofold: First, the stock was slightly low and short. I occasionally got my thumb in my nose.. It also belted me a wee bit more than I liked, and did from time to time give me a headache after shooting a few rounds. I think that could've been cured wit a better stock shape for me?
I also found the open sights to e rather useless.
In total it wouldve been a considerable cost to get it fixed to my specs.
I'd rather sell it and put my $$ into a different double that fits well.

I also would like to have a scope mounted, preferrably a 1,5-5x20. The stock should be fitted correctly for use without the scope.

Based on this, which caliber would You advice med to get?

.450/.400 or .450?