I can't get my bullets seated in far enough and they seem to be colapsing are my necks to thick.This is a rush because the moose rut is around the corner.

If you're using new brass, did you chamfer the case mouth? If you didn't, that can crush the neck when seating bullets.

What dies are you using?

I agree; in addition you can choose boat-tail bullets, that are easier to seat.

A couple of things could be happening. First, back off the seater/crimp die and re-adjust the seater plug to make sure that no crimp is being applied for the bullet seating step.

Are you sure your charge isn't taking too much space in the case? Different bullets have different lengths of course and if you are trying a new bullet you may be running into the powder charge.

Varmintshooter, I've seen this quite a bit with the WSM's and other short necked fat bodied carts (6.5x284 etc). You have to really ease up on the seating depth dimension. There doesn't seem to be a lot of difference between proper seating and the crimp getting into the neck and crushing it. Try backing way off on the seater, until it isn't getting the bullet into the case at all, and then sneak up on your final seating depth real slowly, maybe 1/8 turns in at a time.

Also to eliminate the possibility Wink suggested of the bullet getting into the powder, try the seating setup on a case that isn't primed, charged.

I have not seen any issues with WSM brass being thin in the neck, losing tension quickly or other neck, case issues. Typically the brass resizes quite readily, and holds good tolerances after sizing and is long lived in my experience. I've got some cases that are doing quite well after 35 or 40 resizing operations.

Good Luck--Don

I reloaded about 4000 cases of 300WSM and I must say that winchester brass goes for 4-5 reloadings, and that the fragile point is the neck. (longitudonal cracks after being fired the 5th time are common)

Norma brass is a lot thicker (but takes about 1.8 gr LESS powder therefore!!).

It's true about chamfering the neck before seating the bullet. And even when hunting, I'd go for NO crimp.

Try the sierra 180gr spitzer boat tails.
Great accuracy up to 600m.
Chamfer the necks before seating the bullet and use the softer winchester brass (easier seating), or use the tougher norma brass for that 1x extra use...