+1 for 300 rum both are great rounds and not much in them ,the big weatherby will have 100-150fps over the rum and use 10+ grains of powder more to do it,it also depends on the rifle, if you are building a custom or buying a factory built,hard to go past a 300 rum sendero for out of the box performance and if you find that the 300 isn't enough gun you can rebarrel for a 338 rum or edge.
You said you wanted a good elk rifle. Then why not get the best? Both of your choices require a muzzle brake and you will not notice the difference between them and a big 338 with a brake. There is no comparison to an elk getting shot with a big 338 vs. any smaller caliber. And when you make that marginal shot you still get your elk. Or have to drive a bullet through at a bad angle you still get your elk. And when you get back to camp you can be the guy who always can say yep, I got my bull. Instead of being like others who always have the same excuse. I hit a huge one and it got away. Or it was a bad shot angle and I didn't shoot or I shot and didn't have enough gun. I lost it.
I guess when you talk to people about an elk rifle you need to think about who you are talking to and listen to fact and not opinions according to what people have read. I would listen to people who have seen hundreds of elk get shot over 30-40 years and then make a decision. Those kind of guys have seen it all along with all the sad and sick faces in elk camp with all the excuses why they are not the one with the big bull. I can tell you my time is very important and chances at trophy bulls are very limited so I shoot what will put an elk down right now to stay. With current bullet availability nothing beats the big 338's. In a factory rifle the Weatherby Accumark in 338-378 wby is the best elk rifle available. On a budget a remington 338 ultramag is not very far behind and is what I got my big bull with this year at 740 yards. I was backpacking and used a lighter gun than my big heavy 338-378. If you go custom do a 338 Lapua Imp. or a 338-378 wby. Most of the time you will kill your elk with any rifle you choose. But if your going to spend the money why not get the best for all occasions.
You said you wanted a good elk rifle. Then why not get the best? Both of your choices require a muzzle brake and you will not notice the difference between them and a big 338 with a brake. There is no comparison to an elk getting shot with a big 338 vs. any smaller caliber. And when you make that marginal shot you still get your elk. Or have to drive a bullet through at a bad angle you still get your elk. And when you get back to camp you can be the guy who always can say yep, I got my bull. Instead of being like others who always have the same excuse. I hit a huge one and it got away. Or it was a bad shot angle and I didn't shoot or I shot and didn't have enough gun. I lost it.
I guess when you talk to people about an elk rifle you need to think about who you are talking to and listen to fact and not opinions according to what people have read. I would listen to people who have seen hundreds of elk get shot over 30-40 years and then make a decision. Those kind of guys have seen it all along with all the sad and sick faces in elk camp with all the excuses why they are not the one with the big bull. I can tell you my time is very important and chances at trophy bulls are very limited so I shoot what will put an elk down right now to stay. With current bullet availability nothing beats the big 338's. In a factory rifle the Weatherby Accumark in 338-378 wby is the best elk rifle available. On a budget a remington 338 ultramag is not very far behind and is what I got my big bull with this year at 740 yards. I was backpacking and used a lighter gun than my big heavy 338-378. If you go custom do a 338 Lapua Imp. or a 338-378 wby. Most of the time you will kill your elk with any rifle you choose. But if your going to spend the money why not get the best for all occasions.