I have always set the seating depth with the base of the bull it at the bottom of the neck with out letting the bullet protrude into the powder area of the round. I have not had any problems loading this way.
I lived in Alaska for four years in the inside passage. I started out with a 300 win mag. Then I seen a brown bear grizzly, at that time I sold the 300 and picked up a 375 H&H. After talking with the old timers in that area they all told me that the smallest bore they would use is a 35 cal, and...
You are right rem triggers are fully adjustable for pull weight over travel and sear ingagment. But a good cleaning with break parts cleaner followed by a good spray lube helps. I have used gun slick on the sear ingagment to reduce pull weight by 1lb.
Any case that has neck thickness problems is a bad case. Plus case weight changes that are to far light or heavy. A case that is banana shaped is caused by the exstracter, why bench rest shooters have them removed.
I have had this happen to me. What is going on is the case is flowing forward when you fire it in your rifle, to get rid of the donut you need a inside neck remember fo your caliber.
I have yet to shot an elk past three hundred yards yet, most have been no longer then one hundred yards. But a 7mm mag just will not have the killing power at 1000 yards. Probably the best rifle would be a 378 or 340 Weatherby at 1k.