My 7mm rem mag produces 6" groups, (yes half a foot) @ 100 yards within 5 shots. Then my 243 is one moa accurate for a long dang ways for 5 shots.
The 7mm rem mag was my first rifle and didn't know anything about em except for taking animals. Well, several times at on the range the barrel was glowing red and rarely ever cleaned. Ya think its ruined?
The 243 has been broken in properly, never shot more than 5 times at once, barrel cools down before more shots are taken, and the barrel is cleaned about every 30-40 rounds.
Well that is what I am thinking, I have a better chance of killing any animals with the 243 doing head shots only than trying to hit anything with my 7mm.
I think you need to get your 7mm checked out and go from there. I doubt the barrel has been shot out unless you've put a couple thousand through her, but the throat could be shot since you say it wasn't allowed to cool properly. Is everything tight, scope rings, bases, action screws, etc? Are you shooting from a bench?? Are you using handloads or factory??
It would be far better to take care of your problem now at home with the 7mm, then in the field with an elk on the line and a very marginal caliber/bullet selection at that.
If you plan to use a 6mm cal for elk, stick an X bullet, Aframe, or any other premium bullet that holds 90%+ weight retention so that it penetrates to the vitals. A VLD is not exactly a bullet that holds together very well in my experience.
I hunt with several guys that use the 243 for everything including elk and they do great with it. None of them shoot the Bergers, most shoot something with a soft point like a cor-lock. None of these guys shoot elk over 300yds and they all shoot them behind the shoulder, they are careful.
Between the guys I know using the 243 there are over 50 elk between them all taken clean from what I've seen. Alot of kids around here start hunting elk with a 243. Ideal, maybe not but it will work if you know your limits with your gun.
I would worry about the vld having enough exsplosive capasity to get it done, vs. a good mushrooming bullet making it to the other side.