I have been working on an other cartridge as many of you may know. It is a variation of the 348 Ackley Improved. The case is 2.250 OAL and the shouder is 25 degrees withthe shoulder diamiter of .520'. You can use the 348 blown out but they are short by about .030" once fire formed, or you can use the 50-110 case trimmed back to length.
With this conversion I get the same velocity as the improved but almost no work needs to be performed on the action. I did one that needed NO work at all and they feed just like the original 3248's.
I have loaded the Barnes 220 gr. and the 250 grain bullets and they are running 2500 FPS for the 220 and 2400 FPS for the 250's

I shot a Red stag this last week in Ethel MO. at the Heartland Wildlife Ranche with it and recover the bullets. They were 182 and 192 grains recovered. tehy started out at 220 grains at 2500 FPS muzzel velocity. The 192 bullet was shot at 50 yrds and revovered in the shoulder and the 182 was shot at 10 yrds to finish it and recovered in the sandy soil after going thru the chest.

I had mounted a Nikon 2.5 X 8 Extended eye relief scope on the barrel. It works really great for seeing any sticks in the way and for bullet placement as it is very precise on a non moving animal. I shot the stag running and it takes a bit more practice to use the extended eye scopes over a traditional scope.

I will get some pictures posted or go to my face book page under Doug Turnbull or the one on Turnbull Manufacturing on face book.

Congrats on the hunting and cart/gun combo success.
At 358 Win power+ that is something! A good plains game match for the 470 Turnbull.