How do you know when the sizing die "just touches" the shoulder?


January 31, 2003, 04:04 PM
So far I've loaded only straight-wall revolver rounds, but now I'm getting ready to dive into bottleneck rifle rounds. I understand headspace, and the importance of not setting the shoulder back too far. So when I'm adjusting my sizing die, how do I tell that "right there" is where it's just touching the shoulder?

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Bill Adair
January 31, 2003, 05:41 PM
Don't know what kind of gun you are using, but here is some general information that may or may not apply to yours.

If you are reloading for a bolt action or single shot rifle/pistol, and use your reloads only in that firearm, you don't have to full length resize every time.

For an autoloader, you will have to full length resize, because the chambers are generally not as tight, and the cases expand a little more during firing.

Smoking the case neck and shoulder with a candle, and then feeding it into your die a few thousandths at a time, is the easy way to tell where the neck sizing stops, and the shoulder contact begins.

I set up my .223 die, by resizing a once fired case from an autoloader, that was too long to chamber in my gun (Encore).

Kept tightening the die down, until the sized cases just chambered without force. Rechecked everything a time or two, and seated the rounds in a case gauge to double check, and that is where the die has stayed ever since. If my cases grow, the shoulder will be pushed back, otherwise only the neck is sized.

Incidentally, new Winchester White box 5.56mm will not chamber in my Encore, but new Federal .223 chambers just fine. I can't measure the difference with my calipers, but there is enough difference in the shoulder position that it shows up when I try them in the gun. :rolleyes:


Freedom in theSkies
January 31, 2003, 05:42 PM
drop the handle of your press all the way down, back off the lock collar on your die and screw the die in till it stops. Tighten the lock collar.
Presto change-o

January 31, 2003, 07:59 PM
I agree with Bill Adair. I think Freedom in theSkies might be sizing more than you want.

January 31, 2003, 08:53 PM
I measured the headspace on 5 fired cases for each rifle, average out the value, and resize my cases to that number. With a bolt gun that's easy. I just let the case cool off in the chamber before extraction. With a auto, I disabled the gas system and manually ejected it once the case has cooled off. I got this idea either from Zediker or Jarhead as I recall.

Once I have this measurement, I screw the resizing die down on some old fodder cases and then try it out, slowly adjusting the turns as I approach the correct measurement. Pickup brass works great for this until I get where I think I'm 'right on'. Then I resize my fired brass and see if the measurements are still good. I double check my final case dimensions with a Wilson case gauge.

I know there are ways of casting the chamber for headspace, but I've never done that. I'm afraid of accidentally leaving gunk in there.

January 31, 2003, 09:32 PM
Thanks - I think I'll give the smoke method a try.

Freedom in theSkies
January 31, 2003, 09:43 PM
:eek: Sorry!
I did'nt read the question properly!

Again, sorry for my inadvertent mislead.:o

February 4, 2003, 02:08 PM
Several ways

Get a case gauge, and measure the fired case. Now, unscrew your sizing die a little, and then start screwing it in and sizing until you see that you're bumping the case about 0.001" or so. You're there.

If you've got a Remington (or some others - I forget...) action, call Sinclair's and get a firing pin removal tool. Put a fired case in the chamber (with the pin out) and see how much pressure it takes to push the bolt down. Keep sizing the puppy until the bolt drops with just a little pressure.

When you do either, stick with one batch of brass, since variations cause variations.

February 4, 2003, 05:48 PM
Thanks for the info.

New question: All these methods assume fired cases. What do you do with a batch of new, unprimed brass?

And Bogie - I've never understood the "closing freely" thing. If a case came out of a chamber, it stands to reason (doesn't it?) that it should go right back in.

October 6, 2006, 12:03 AM
Your're correct, they do go right back in. And that's because of brass's ability to "spring back after firing". If cartridge brass did not have this property, what problems we would have. I find after a few firings in a break open like the TC Encore Rifle, neck sizing only will get you in trouble, as the "spring back" gets less as the brass is fire hardened. Then you start having extraction problems, as the brass clings to the barrel. This comes on faster with a break open as it does not have the extraction power of a bolt gun. Had one today, with a average hunting load in a .280 AI, my Encore would not open until the cartridge cooled down. It was only one out of 10 fired from same virgin unprimed brass I had fireformed the day before, and I only neck sized them. They all went in the chamber but were a close fit. It will eventually show up in bolt gun too. So, a careful FL sizing without pushing the shoulder back, is needed, at some time before case becomes unusable for other reasons. I'm going to do a partial FL for this Encore from now on, don't need sticking cases in a hunting piece. If this happens in an Encore, there is no bolt to tap with a mallet etc., You can try cocking and pulling the trigger, a second hit on the primer sometimes will loosen the case. Or tapping it from the muzzle with a cleaning rod that will go down to the case head.

October 6, 2006, 01:23 AM
I don't have a headspace gauge to actually measure brass.

So when I set my full length sizing dies for a specific gun, I do it my trial and error. I will do it on a specific FL die for one specific rifle. When I get a lot of brass that has been necked sized and reloaded several times and I know the bolt is getting hard to close, I set the FL die, resize and test in the rifle. I keep turning the FL die down slightly and resizing brass and testing until I find the bolt turning tension to be just right.

October 6, 2006, 08:46 AM
New question: All these methods assume fired cases. What do you do with a batch of new, unprimed brass?


With new, unfired brass, there is no need to resize the cases, as they are already sized with the equivalent of a small base die. Just chamfer the case necks, prime and load.


Doug b
October 6, 2006, 08:54 AM
I use the Stoney Point head and shoulder gauge for getting the the least amount of shoulder bump.
I've found the difference between to much and not enough is up to the amount of pressure the die applies to the shellholder. The rule of thumb instructions supplied by the die manufacturers,although they do work grossly oversize.

October 6, 2006, 09:52 PM

highlander 5
October 9, 2006, 05:17 PM
rather than smoke I use a magic marker on the neck and stop at 1/16' short of the shoulder. BTW cases for lever pump and auto
rifles should be FL sized for reliable feeding

October 17, 2006, 03:43 PM
It is a fairly common misconception that the 5.56 chamber and the .223 SAAMI chamber are the same. 5.56 NATO is slightly larger in the leade area and will not and should not be shot in a precision chamber.223. If a rifle is stamped .223 one should NEVER use 5.56 ammo. It is loaded to higher pressure and "could" cause an over pressure. .223 however should be OK in 5.56 though.

Google the Ammo Oracle for a complete explanation. Or check wiwth SAAMI specs. If you want a good defense weapon get a 5.56 chamber as it will handle both rounds. There was a compromise chamber called the Wylde but it is not very popular. Not all AR manufacturers mark the barrels correctly either. Take the time to read the Ammo Oracle. Very informative.

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