Something I noticed about my dies

I have the Lee Deluxe carbide sizing dies for .45acp and for .40 S&W. I notice that both dies size the cases smaller then the spec dimensions should be. The .40S&W dies does more so then the .45 die set and the same goes for my fathers. I noticed when full sizing cases you can see where the case web starts instead of a smooth transition.

For example the dimensions of a .40 SW are supposed to be .424 at the case web and .423 at the mouth. My brass after being sized comes out at .422 at the case web and .419 at the case mouth. I also ran my brass through the Lee factory crimp die (which has a post sizing carbide insert) instead of through the main sizing die. That brass came out measing .422 at the web and .422 at the mouth. I had my dad do the exact same thing with his set and he got the same results. I plan on calling Lee to discuss this and see what they think of it.

Does anyone else's dies size their pistol brass like this? It is under spec but I dont think it will cause any big issues except possible shorter case life.

I ran a few through my Dillon dies on the Square Deal Press. I basically got the same as you.

Anywhere betwee .416-.418 at the mouth and .421-.423 at the web...

I have Lee 45acp (same set as yours)and 9mm dies.... My 45's "look" right to me after loaded, so I never really measured to see what they actually are sized to. My 9mm's look like they might be resized on the smaller end of the spectrum since I can see where the base of the bullet is seated to through the case wall...they work, so I never gave it a second thought. Maybe I need to take some measurements?

Makes for good bullet tension. I would not worry about it. You would not want your bullets fitting loose.

I post size all my loaded rounds for my G20 10mm as a last step, so I never really paid much attention to what they were resized to. As long as they were feeding through/chambering fine in my Glock I didn't worry about it.

The main thing I was ever concerned about was the mouth expanding die, gotta watch that one cause it works itself loose and will flare the case mouth till it splits if it creeps down without me knowing it. I have a piece of tape around it now so it will stay put.

I know this doesn't answer your question very well, but I guess what I'm getting at is if your rounds are chambering well and functioning through the weapon well, I wouldn't worry too much about it.

There are many guys who load for .45's that never even trim their brass at all, just resize, load, seat, crimp and shoot. Has anybody else ever read this before?

I don't trim brass for 9mm .40 .45. Just load and shoot. never had a problem. However for .357 .38 and all revolver ammo it needs to be trimmed to get a good roll crimp