Brent,
The most common problem with reloading belted magnums is when people adjust their resizing die down against the shell holder. This pushes the shoulder back and headspaces on the belt. This will split cases and shorten case life for sure. I have talked to many shooters that thought doing this would make their cartridge smaller so that they would chamber better. (They've found out that it doesn't work). Try this test using just "one" case: Reload a new case, fire it, reload it, and measure the area "just above" the belt. Then repeat the process again and again until the case won't chamber. You will find that every time that you measure the case, it has increased in diameter, in the web area, until it won't chamber. The reason that a conventional resizing die can't properly resize belted cases is this: In order to resize any given area on any case, you must press the die "slightly" below that area. Because when the case is withdrawn, it "springs back" a little bit. As long as a conventional resizing die has to stop at the belt .... it will never be able to fully reduce the case diameter "just above" the belt. Take a look at my web site
www.larrywillis.com where you can see the article that I wrote for Precision Shooting on this subject. I've spent a year researching this problem and designing a resizing die that would solve this problem with reloading belted magnums. My next step is to post a long list of product endorsements that I've been collecting to my web site.
WOW!!
Your first sentence IS the reason why people get 3 reloads with belted magnums, not because they are NOT using your die. PERIOD.
What you should be peddling is a case head CLEARANCE GUAGE so that people can adjust their dies CORRECTLY so their cases are headspacing off the shoulder, not the belt. The belt is useless after the case has been fireformed to the chamber, normally, my shoulders move forward by an average of .026", yes, I actually MEASURE this aspect of my cases.
Oh, I have a question, all the squeezing of the case just above the web, or as you put it, the belt, by your collet die, where does the brass flow too, and, does it cause excessive stretching, and therefore thinning, of the brass in this area?
My thinking dictates that the brass must be displaced elsewhere along the case, causing excessive thinning after each sizing operation, just like a FL die causes the neck to grow, does your die stop this, too?
I doubt it immensely.
I have been loading belted cases since I was 16, NOT ONCE, have I had a case head separation with a belted case or the dreaded bulge, as you call it, haven't even seen it on others cases.