Help Me Understand Full-Length/with Bushing Resizing

[gunsandgunsmithing]

I start by running the sizer in to just touch the top of the shell holder then back it off maybe 1/16 of a turn. A 7/8-14 die is basically .0715 per revolution, so 1/16= about .0045".
Start there and the case will either get longer or shorter, in all likelihood. Chances are, longer at that point. From there, adjust the die down very slightly until you get the desired bump. You can use a depth mic or the stem on a good set of calipers to get really close once you establish a setting and how much you need to change it for the number you're after. You just measure from the top of the die to the top of the press, etc.

 

[JFrank]

If I may return to my original post in this thread, I guess I've learned that--aside from chambering and extraction issues--a main advantage of FL sizing over neck sizing is that all cases end up with identical dimensions. Presumably, with neck-only sizing, some cases may end up very slightly larger than others because they had been loaded to higher pressures. This consistency in exterior dimensions may lead to more accurate loads. This all assumes that the slight reduction in outside case-body diameter resulting from FL sizing is inconsequential with regard to causing worse centering of the case in the chamber than would be true with neck sizing. (That was what I had always thought was the advantage of neck sizing--having the loaded round absolutely centered in the chamber, rather than lying on the bottom of the chamber.) Thanks to everyone for the tutorial.

So I get it. I've now ordered up a L.E. Wilson full-length bushing die and the corresponding case gauge, directly from Wilson. One question I have about the case gauge: can you get accurate enough measurements with it using a vernier caliper? Or do you need the case gauge depth micrometer to use the case gauge properly? I have a dial caliper (not digital).

One other question. When using the FL die, do you start by trying it out with the die up slightly from the shell-holder to bump the shoulder the least and then check with the case gauge just how much you've set the shoulder back? If, say, the bump is less than .001", do you then screw the die in very slightly more, size the case, and then re-check with the case gauge, continuing this way until you've set the shoulder back by .001" to .002"?

Wilson makes really nice stuff

 

[Enosiophobia]

Can you screw it in further and still make a full stroke? I used to load my ammo single stage on a Hornady AP like this. Eventually I got the shoulders to move.. by screwing the die in much farther than I thought possible. I also put a dummy die in one of the locations opposite where I was sizing, and ensured it was touching the shellplate. This provided some equal pressure on the shell plate and prevented some torqueing.

If none of this still works.. trim the die shorter as Dusty says.

You were correct. What I didnt notice until I looked very closely is that the shell plate "flexed" and until I turned the die down further, it wasnt applying full pressure to the case. Seems to be working out fine now. Guessing this is a quirk with non single stage dies, or perhaps just LNL presses.

 

[Jdne5b]

You were correct. What I didnt notice until I looked very closely is that the shell plate "flexed" and until I turned the die down further, it wasnt applying full pressure to the case. Seems to be working out fine now. Guessing this is a quirk with non single stage dies, or perhaps just LNL presses.

Glad you got it going. The LNL loaded me lots of very accurate ammo once the quirks got figured out. If i hadnt switched to a 1050 for pistol I would still be loading pistol and rifle on it.