Adjusting FL die for Headspace

[Big Fritz]

I'm new to reloading. How do you adjust the die for headspace? The RCBS directions say to run the ram to the top and bring the die to it and tighten it down. If you turn the die tighter, does that make for more or less headspace?

 

[firearmdoc1]

The further you turn the die into the press the farther the shoulder will get set back causing greater headspace. There is a limit to how far you can screw the die in though.

 

[Big Fritz]

Thanks for the quick reply. What I did was try and chamber my already fired unprimed brass (cleaned). It wouldn't chamber, although I didn't force the issue. So I gave the die about and 8th turn...ran the case thru the die again and it fit just fine....so how much headspace is that?

 

[Nomad47]

A 1/8 turn of the die is .0085". 8.5 thousandths. You should use the Stoney Point (oops, Hornady) tool with headspace gauges so you know when you have bumped the shoulder a couple thousandths. Otherwise turn the die 1/32 turn at a time until the fired brass chambers easily.

 

[Erik Cortina]

Thanks for the quick reply. What I did was try and chamber my already fired unprimed brass (cleaned). It wouldn't chamber, although I didn't force the issue. So I gave the die about and 8th turn...ran the case thru the die again and it fit just fine....so how much headspace is that?

We can't tell you because we don't know, you would have to measure that. Hornady makes a headspace gauge that attaches to your calipers so you can measure the before and after measurements.

The die will move about .072" per turn, so 1/8 turn is about .009", which is too much.
What I do is make a witness mark between lock ring and die, and turn it only so the left side of one line lines up with the right side of the other and try again. You can back it off from where you are at now until brass is snug, then go back the other way so that your bolt closes about 80% with no resistance (without firing pin assembly). This will get you very close without causing excessive headspace.

Then F/L size every time you fire the brass.

 

[BoydAllen]

If you raise the ram all the way, lower the die till it makes contact, lock it there, lower the ram, and put a properly lubed case in the shell holder, and then raise the ram again, sizing the case, you will observe a gap between the shell holder and the die that was not there before. I would guess that comes from the slack being taken out of the linkage that connects the ram to the press handle. Years ago, I used feeler gauge set to measure the gap after running a .220 Swift case up into a RCBS FL die. It was .006. So, there is a small amount of adjustment that can be done beyond the point where an empty die touches an empty shell holder. The press was a Rockchucker.

 

[Nomad47]

That is true, Boyd. And the WSSM brass is notorious for needing the die to be turned a little past "shellholder contact".

 

[Big Fritz]

Thanks to all for the resposes.....It's intersting that you said WSSM...I'm reloading 243 WSSM in a Browning SS A-Bolt. The gun shoots ok groups , but doesn't feed well unless I allow alot of jump.

 

[Nomad47]

IIRC, you have to jump the majority of bullets .030 to .040 to get the rounds to load in the detachable magazine.

 

[Big Fritz]

I'm sorry...I don't know what IIRC is...

Stupid question....If I go too far with the die can I go backwards until the case won't feed?

 

[fdshuster]

"If I go too far with the die can I go backwards until the case won't feed?

No. To move the shoulder forward, it would have to be loaded and fired in your chamber. If this backward (by oversizing) and forward (by firing) moving of the shoulder were to continue as a regular practice, case life will be short, with case head seperation much earlier than if sized the minimum amount necessary to chamber.

The die makers, like RCBS, are not doing anyone any favors by their instructions to adjust the sizing die to touch the shellholder, then back it off whatever distance.

The proper way of doing it is to get the before mentioned Hornady chamber over-all-length gauge and take some precision measurements of your fired brass, then adjust the sizer die to push the shoulder back approximately .002" to .003" shorter. If the case measures 1.575", then set the shoulder back to 1.573" or 1.572". Just using numbers pulled out of a hat, only for an example.

 

[steve4102]

I'm new to reloading. How do you adjust the die for headspace? The RCBS directions say to run the ram to the top and bring the die to it and tighten it down. If you turn the die tighter, does that make for more or less headspace?

I use a Stoney Point gauge, but this is how an old timer I knew did it without a gauge.

1. Put the Shell Holder in the press and raise the ram.

2. Screw the Full Length(FL) Die into the press so it is about a "nickle's thickness" above the Shell Holder.

3. Lube a "Fired" case (walls and inside the neck) and squash it.

4. Remove the Lube and try closing the bolt on it in the chamber.

5. If the bolt closes with no resistance, screw the FL Die into the press about 1/8-1/4 turn and repeat steps 3 & 4.

6. As you feel the resistance begin, slow down how much you screw the FL Die into the press so you are at about 1/16 of a turn, or "Fine Tuning". At some point you will not be able to close the bolt and you are extremely close to having the FL Die in the proper position.

NOTE: The reason for this is because the FL Die has begun Resizing the Case-walls down to the Pressure Ring. As it does so, the Case-body lengthens slightly which in turn moves the Case-shoulder slightly forward. Then as the "Fine Tuning" continues the Case-shoulder makes contact with the FL Die and is moved slightly reward(or slightly shortens the Case-head to Case-shoulder dimension).

7. Stop when there is a slight bit of resistance when closing the bolt on the empty case. You now have a "slight crush fit" for the case in that specific chamber, or Zero Headspace.

8. Once you get it where you want it, take some masking tape or a black marker and put a Witness Mark where the FL Die Lock Ring is positioned to hold the FL Die in this position. Loosen the FL Die and return the Lock Ring to align with the Witness Mark and sung up the Set-Screw.

Screw the FL Die back into the press and try squashing another case. It should have the same resistance as the previous one. If not, you need to re-adjust the Lock Ring so it does. But you are extremely close to where you want it, so make very small changes at this point.

 

[fdshuster]

steve4102: You are correct, and that's the way we did it before the original Stoney Point gauge came on the market. Either way works fine, the gauge just makes it a little quicker without the trial and error adjustments.

Big Fritz: A suggestion. Be sure to have a lock ring that is split with a cross-bolt for tightening rather than the older style that has a very tiny set screw that makes contact with the 7/8" threads on the die body. I've always had to remove the die from the press and put it in a padded vice to get the lock ring loose enough to adjust. With the cross-bolt lock ring it's easy to make fine adjustments on the lock ring without removing the die from the press.

 

[Nomad47]

I'm sorry...I don't know what IIRC is...

Stupid question....If I go too far with the die can I go backwards until the case won't feed?

IIRC = If I Recall Correctly

 

[FroggyOne2]

I take a fired case, put the die in the press, lube up the case and measure the case after every movement of the die till i get a measurement that i have bumped the shoulder back .0005 from the fired measurement. Seems to work for me,

 

[BoydAllen]

If you get out your pocket calculator and divide 1 by 14 you will see how many thousandths that a die is advanced in its threads in one turn, a little over .071, so if you work with the coarse adjustments that have been described in the previous posts you will have a hard time hitting your mark. Second, GET THE TOOL (Hornady), and do it right. Pretty much all of the properly done chambers that you will run across will be sized with the die less than a dime's thickness from the shell holder, so you don't have to start from so far above the shell holder. Work in small increments. You are looking for a shoulder bump of .002 or less. If the fired brass will chamber easily, your can actually set the die to recreate the head to shoulder measurement of the fired case. To come up with a reference for setting bump, you really should have a case that has been fired till tight in your rifle. Also, when you use the tool (on your caliper) to measure the fired case, either use a punch to remove the primer before measuring, or just reseat the fired primer so that it is well below flush.

 

[bigedp51]

Big Fritz

Plan "B" keep your change in your pocket and set your dies up as per your instructions and "shim" the bottom of the lock ring for proper cartridge headspace.



Sinclair Full-Length Sizing Die Shims
http://bulletin.accurateshooter.com/2013/03/sinclair-full-length-sizing-die-shims/

Or you can buy the Redding competition shellholder set and use shellholders that come in taller heights to control shoulder bump.

Redding Competition Shell Holder Set
http://www.natchezss.com/product.cfm?contentID=productDetail&prodID=RB11601

Plan "C" the cheap bastards way, place a feeler gauge between the shellholder and the bottom of the die. Start with a .010 thick feeler gage and the ram fully extended, place the feeler gauge on top of the shellholder and screw the die down until it contacts the gauge. Keep decreasing the thickness of the feeler gauge until proper shoulder bump is achieved.

Below at the top of the photo is the Hornady cartridge case headspace gauge for measuring fired and resized cases.

 

[BoydAllen]

Ed,
All of the methods of adjusting that you mentioned cost more than just turning the die in the press, and whether you use shims, shell holders, or just turn the die, one needs a way to determine where the die needs to be set....yes? Nice picture
Boyd

 

[Nomad47]

Die threads aren't exactly 14 TPI, that is the nearest whole number. One thread (turn) works out to .0695". If you can picture the 60 minutes on a clock face, turning the die one minute (1/60 of a turn) will change your shoulder bump by a smidgeon over .001".

 

[bigedp51]

Ed,
All of the methods of adjusting that you mentioned cost more than just turning the die in the press, and whether you use shims, shell holders, or just turn the die, one needs a way to determine where the die needs to be set....yes? Nice picture
Boyd

In the 1974 Speer reloading manual number nine there is a chapter called "Modern Benchrest Reload Techniques". What has stuck with me all these years were the simple instructions for removing die alignment error in the press.

1. Centering the die in the press and remove the slop in the die threads by placing a lubed case in the shellholder, raise the ram full extension and then tighten the die lock ring.

NOTE: This prevents locking the die off center and also prevents the die from being locked down "tilted or leaning". Also the Redding Competition shell holders allow the die to contact the shellholder and remove even more misalignment.

It is important to rotate the cases in the shellholder and check for freedom of movement and binding. The rims on autoloaders M1, M1A, AR15 can get dinged and bind in your shellholder and cause alignment errors.

2. More neck runout is caused by the decapping pin/expander button being locked down off center than any other cause.

On the down stroke of the ram just as the ball expander enters the neck is when you tighten the lock nut on the decapping stem. This centers the expander button in the neck of the case and reduces neck runout.

NOTE: With the exception of cases fired in semiautos and cases with dents and dings on the inside of the rim that can hold the case off center on the down stroke.

I believe by using the Redding Competition shellholders a person "without" gauges will be better off and reload more accurate ammunition using the steps above.