Well, some would say that it is a bad design due to the small shoulder.
Personally I think that is poppycock!
I owned a TC SUPER 14 IN 35REM. a cartridge which also has a very small shoulder and in some circles the rep of poor case life.
Hmmmmmmm well maybe?
??
When I got that 35 Rem barrel, it came with a box of fired brass, the use on which I never knew, but when I sold the barrel that box of brass had been fired 17 additional times..
This 35 Whelen problem sounds like there is enough guilt to go around, with some problems, at times, on both sides of the manufacturing process.
I know this would be a pain, but I think the way to go ON THE FIRST SHOT, is to seat a bullet, maybe a cast boolit, LONG and into the lands to be fired with a good fire forming loads.
Then never ever allow the sizing die to do anything more then possibly (
??) kiss the shoulder.
I used the above fireforming method, WITH GOOD RESULTS, to form new 30/06 brass into 30 Gibbs.
The forming load, depending on how stiff it is, may not fully form the brass, but it needs to be stiff enough to make sure the shoulder is solidly in contact with the chamber's shoulder.
After that forming load, the first full power load will blow out all the corners.
Keep em coming!
CDOC