I'm new hear and cat fish asked me to post some data on some of the wild cats Iv'e worked with. ( Intoductions)
Catfish you didn't say witch so i will post my 3 fav.
338 ultra shortend .1875 to fit 30/06 actions. (ruger m77)
My sons and I wonted a 340wby in a control feed ruger! For hunting big stuff in north amer. The 340wby has enough power to do it!
I bought 338 ultra dies took .1875 off the base full lainght sized 100 brass, used the brass as a go-gage

From the start this cartridge was vary easy to work with.
The ruger took it with only one alteration. To get 3 rounds in all I had to do is mill a little off the floor plate so the bolt wouldn't dragg to hard on the first round up. (top round)
225gr interbonds 90.5gr rl25 fed match mag 3007fps avg. groups under .75 4517flbs.
250gr accubonds 81.5gr h4831sc fed match mag 2885fps avg. groups .656 4604flbs
goal acheaved! (this is in 24.5" barrels) avg. vol. is for 4 diff. rifles.
The next one is the same shortend ultra case necked to 270.
This one is a little finicky to reload. And brass is a little harder to make.
We wonted a super flat shooting mule deer rifle with enough horses to get the job done out hear in the desert! (long shot)
The rifle had to be a light packer. Handle easy no muzzle brake. barrel under 26"
so we dicided on a 270 so we could shoot eather 130-140gr bullets!
We realy wonted to beat the 270wby with no belt!

the brass is a trick I had to buy 300,7mm ultra dies take .280 off the base . 270 wby dies was bored out to fitt ultra cases!
The brass needs to be aneled before forming!
the new case was used as a go-gage
after a hole bunch of different loads we just about gave up when we loaded 79.0gr RL22 130gr accubond.Presto 3615fps avg group .389
3 more rifles made for my sons and thay all love that load!
The 3rd round is 338-300 ultra (thay call it the edge naw)
We wonted a heavy waight for long range big game shooting (mine scales in at 16 lbs)
1.25 bbl 5" straight then taper to .925 at muzzle 28" long
we setteld on .225 interbonds 100.0 gr Rl 25 fed match mag 3256fps
longest shot 1437yrds rock chuck
1181yrds mulie
1064yrds elk
We have killed all kinds of deer,elk,antilope with this rifle and all of them have been one shot kills. ( the closest shot 412yrds)
I've been long range shooting sence 1982. I'v'e wore out at least 12-14 rifles doing this.