Why the Lee U die? Is there a reason why an undersize sizer die should be used? Last, I'm not trying to sound stupid but on my SDB it has a powder through and flare die then a seating die on your setup when is the powder added? Is it a die? Thanks.
A couple of reasons. The first is it sizes all the way to the shell plate. Of course there are other dies that do this so it's not that big a deal. The second is the fact that it sizes slightly under keeps more consistent neck tension on the bullet to prevent set back, get's rid of glock bulge fairly well and the absolute biggest reason is because I have far fewer rounds fail case gauge.
I assume the better pass rate is because older brass that has less elasticity still makes it through the case gauge and chambers perfectly since it sizes down a bit further.
There is nothing worse than blowing a match because of a malfunction. Keeping the ammo feeding 100% is a huge key to being successful.
My 650 has 5 stations:
Station 1 - case feed and decap/size - Lee U Die
Station 2 - Prime/ Powder through Expansion - Dillon funnel/expander and powder die
Station 3 - Powder Check - Dillon
Station 4 - Seat - Redding Competition Die
Station 5 - Crimp - Lee FCD
My 1050 has 8 stations:
Station 1 - Case feeder
Station 2 - Decap/size - Lee U Die
Station 3 - Primer Pocket Swage
Station 4 - Prime (primes on up stroke)
Station 5 - Powder through Expansion - Dillon funnel/expander and powder die
Station 6 - Powder Check - Dillon
Station 7 - Seat - Redding Competition Die
Station 8 - Crimp - Lee FCD