Primer Seating Depth Issue

I have never ran into this before, nor have I seen LR primers with such a huge variance in height!! Interesting post, I don't have anything to add other than I have been uniforming primer pockets for years now and have never had a problem like this.
 
I had problems using S&B brass, and eventually figured out that the primer pockets were too shallow.
Once the pockets had been "uniformed" I had no problem seating primers.

Actually I think the problem with S&B brass (at least 45 ACP) is nor shallow primer pockets but rather tight primer pockets. I use a Lee hand primer and when priming S&B brass it definitely requires more pressure to get primers seated in the primer pockets. The uniformer also enlarges the primer pocket in addition to cutting it to the proper depth. I don't have one so I use a #4 drill bit to enlarge the S&B primer pockets (I ground the end flat so it does not deepen the primer pockets and after a quick pass with the drill bit primers seat with far less pressure.

I don't know if all S&B brass is like this but the 45 ACP definitely is, so much so that most of my friends who find it at the range and who reload on progressive presses don't even bother to pick it up because of inconsistent seating on progressives.
 
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I then measured the height of the primers. The factory Hornady measure a height of .115 and the Winchester measure in at .129, this difference makes all the difference in the world it would seem.

If you are measuring a new Winchester and a used hornady primer, you may not be comparing apples to apples. The new Winchester will not have had the anvil seated in the cup, while the spent primer will have had the anvil seated. When the anvil gets pushed into the primer cup, it is that final "thunk" that you feel through the press handle. Not sure if all primers need the anvil seated? I think I have some older ones that are flush. From the descriptions it is pocket depth/uniformity issue.
 
Glad it worked out for you.

Like I said before I put mine in a cordless drill to make it go faster. I screw the bit into an adapter out of a cleaning kit to make it easier to chuck in the drill, you could probably cut the end off of an old cleaning rod too.
 
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