collet die They are well made.
If it serves a purpose for your reloads get one.
I have one and it works as advertised.
If the cases are bulged as magnum cases do. I use imperial sizing lube and work the case into the die in steps.
I tried to resize a case in one stroke and the cases were sticking pretty bad.
I polished all the pieces that come in contact to the case and it helped.
I have about 8 firings on this batch of 50 and have had 6 cases that split just above the belt.
I run my 7mag through my 300wby die. Fixes the issue every time. 300wby die is long enough if you have some loaded that aren't chambering, you can still run them through.