I have had a few 338 ultra's,a couple 338-378's,340 weatherby's, right now I am shooting a Custom 338 edge which is the 300 ultra case necked out to .338. It just has a slight advantage over the 338 ultra about 100 fps is all. Yes trigger job if needed,bedding if needed and torque the actions screws to 55-65 inch lbs equal front and back.Mine I went 60/inch lbs and it shot great.The 250 or 300 gr bullets are the way to go as far as I am concerned. I shoot only 300 gr.Practice a bunch and get good at 200 yrds then work your way out. It's a blast to say the least!