Help Me Understand Full-Length/with Bushing Resizing

[gunsandgunsmithing]

Is it possible that your smith used a piece of brass as a go gage when chambering the barrel? That may well have rendered the chamber a tad short. Regardless, shortening the die will allow it to bump the shoulder back. It's not uncommon. Believe it or not, there is at times an overlap of acceptable SAAMI standards that can cause problems like this. An example is that is the max brass length at the datum line of several cartridges can be longer than minimum chamber headspace....both within SAAMI specs. That'll cause a tight bolt closure on virgin brass. I suspect your're having a tolerance stacking issue or that the chamber is short. New brass is usually shorter than the chamber but it can happen both ways. If the smith used a piece of brass as a go gage, it would do what you're experiencing. Just cut the die down and life will be good again.

 

[Richard Coody]

Same old same.old

is the fired brass you are trying to bump the.shoulder on fully fireformed? if not then you may be jumping the gun setting up your sizing die for a shoulder bump.

Will a piece of your fired brass chamber without resistance? If so it isn't fully fireformed.

 

[Jdne5b]

I can screw the die in as far as I want. The shell plate is the limiting factor. Once it hits the bottom of the die, that's as far as it will go. The progressive plate is one thickness. To my knowledge, no other plate thicknesses are available.

Yep, just like the one I used. I'm saying you may have some pressure against the shell plate. As long as you can still cam over and complete the stroke, screw it down farther. You'll go from what you're seeing now to setting back .001-.003 in probably less than a quarter turn.

 

[dgeesaman]

I dont think many of them are using the expander button. Also i think they are setting the die to just bump the shoulder back a thou or so . That keeps everything consistent between firings and never the chance of a round being tight to close the bolt on.

This plus your full length die needs to be appropriately suited so that the cartridge body is only pushed back .001 or so on diameter. For factory chambers an off the shelf die will overwork the body too. This usually requires a custom or semi-custom (Harrell’s) FL die.

David

 

[Richard Coody]

Absolutely true”
I also have a standard Wilson case gage for each caliber I’m working with ,( a datum based tool that’s been around since the beginning)
Keeps life simple
J

Correct me if i am wrong but isn't the wilson case gauge made to saami specs?

For me my rifle's chamber becomes my case gauge. Saami no longer matters and i hate to say that because for inexperienced reloaders that could get them in trouble. But then again resizing your brass to saami specs can get you in trouble too!

Lots of nuances in reloading.

 

[rwj]

A question for those that chamber barrels - how difficult/expensive would it be to make a case gauge using the reamer that was used in forming the chamber?

 

[rwj]

Not hard at all

Great news! That’s what I’ll be requesting for each barrel installed moving forward!

 

[boltfluter]

As mentioned, put a die in the press opposite the die you are using to make sure the plate is not flexing away. If not put a feeler gauge under the case for a test. Good luck.

Paul

 

[gunsandgunsmithing]

Order an extra couple inch barrel and your GS will hook ya up.
Ask Mike Ezell about the process ^^^^

I usually make what most people call a barrel widget. It's just about an inch of the barrel cutoff that I run the reamer in just enough to form most of the shoulder. You can then use it to measure the fired vs sized case length with a set of calipers or a big enough mic. Very simple and a handy tool to have.
Making A wilson type is easy enough to do, too. Just a tad more work and you need a longer stub to work with. I prefer the widget.--Mike

 

[South Pender]

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"?

 

[dgeesaman]

I use a dial caliper with some basic level of quality. Something that is truly accurate to .001”, every time. A good Mitutoyo 6” digital is a little over $100 so may be worth hint dropping to your family around gift giving season.

 

[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.

 

[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.