How tight is your sizing die?

[Poppa Bear]

As I was loading up some bullets tonight I ran into some more brass that would not chamber check due to the ring formed during the sizing operation. So I did some experimenting. I have both Lee dies and Redding dies for .40 so I screwed the Lee die into my RCBS and sized a case, I then sized a case using the Redding die. I measured both and the Redding case was .4175 while the Lee was .419. I then did some more testing and found that if I had a case that sized tough using the Redding, which would be one that I would throw away because it would form a ring above the extractor groove, and sized it using the Lee die first I did not form the ring above the extractor. By this I mean that when I felt the case being difficult to size I immediately stopped the operation and ran it through the Lee first.

What I figured out of this is that a case which was shot out of a loose chamber and sized with the Reddings smaller diameter die forced the excess material down forming the ridge. Using the Lee first pushed most of that material towards the center so that the Redding die did not have a lot of excess brass to push down anymore.

So I guess if I want to avoid wasting cartridges, I am going tohave to get into the habit of just running everything through the Lee die first.

That said, what do your dies size your brass down to? It would be interesting to see what line is between a diameter that creates the ridges on cases shot out of loose chambers and the one that always sizes the case without creating a ridge no matter how loose the chamber was that is was shot out of. I already know this, .4175 creates the ridge while .419 does not.

[Sarge]

Are you lubing the cases? I only load 9mm but I use a Udie which occasionally leaves a slight ring(So small that even with the ring mine still gauge and chamber just fine). I get the ring if a case was just too far gone or if I run a dry case through the press.

[Poppa Bear]

Not lubing the cases. A lot of it has to do with the tighter specs of the Redding because I never had a problem with damaged cases with the Lee, but I did have problems with cases being tight going into the chamber. Went to the Redding and cases always fit as long as I do not form the ring above the extractor. I am going to try sizing and depriming a couple of hundred cases with the Lee first and see if they all go through the Redding without getting damaged. It is an extra step but it is just like all the people who use the Lee Bulge Buster or GR-X to prep their cases before they start loading.

[98sr20ve]

Lube the cases to help avoid moving metal in the wrong direction.

Also, both dies seem to be well with in spec. No benefit to overworking the brass unless by some chance you get a extra round in the gun as a result.

[Poppa Bear]

I did some testing with my Lee FCD. I made my own ram and forced a couple of cases through. I then measured the cases and they were at .424. I did some testing on my STI and it needs a cartridge at .426 or smaller at the base to drop fit. At .427 they will fit if I gently push on the case.

I know I can get .424 if I use the Lee Bulge Buster method of prepping the cases, What kind of dimension are people getting who use the Redding GR-X die?