Alan I have not set mine up yet for 10MM, but I will try and snap some pictures from you today. I will say though, that I bought the 10MM set, not the combo 40/10 set, I don't think there would be a difference in the sizing die but maybe there is. The guy who turned me on to these dies some time ago told me if they make a combo set AND they make a set for just the caliber you need, buy the set made just for the caliber you need. I was never given an explanation why but that's how I have done it. Maybe someone can chime in on what the differences would be?
And I only offered up my info on the 40SW because back a few years everyone was saying how dangerous 40 is/was to load, and you HAVE to have a FCD if you shoot from a Glock barrel, blah, blah, blah. And well 40 is a shorter 10MM.
Anyhow, these die sets are top notch and I would really like to see this play out to find the issue, because it would surprise me if it was the sizing die, hence why so many people are after the GRX die, who makes it, Redding, and it's of the same material as the T/C Pro Series die sets.
I will report back a little later, I can snap pics for you, and I will try and see if I can get any clear pics of some of the Underwood ammo I got in my bars to barrel just for chits and giggles.
Florida Glockers Club #2250, BHP Club #2250, Niners Club #2250, G1 Niners Club #2250, Black Rifle Club #2250, S&W Club #2250, 40SW Club #2250