How to measure Headspace

[bench]

Is there a set demension for head space???
I just checked my 308 FTR rifle using once fired brass and Zero fired brass(but FLS) buy adding tape to the back of the case and this is what I found.
Tape .002 thick,both cases took two pieces of tape before I could feel the bolt start to have some friction. So if this is a proper way to check without having headspace gauges? It took .004. to start to feel friction.
Is this OK or is there a better way,is .004 to much to little or OK
Thanks
Bench

 

[tunered]

Your once fired brass will be close to zero, your new brass? Who knows.

 

[fredhorace77]

yes this method will work...i do the same thing on my savages when changing barrels...i use plastic mylar that i have cut to fit the bolt face and they are in different thickness...one thing to beware of is personally i pull the ejector plunger out so that it is not putting any pressure on the case to give me the best possible reading.. .002 is great...nothing wrong with .004 but i personally try to acheive .002

 

[bench]

fredhorace
Yep I have taken out the ejector plunger out to get the bolt handle to drop with its own weight. Thanks for the reply

 

[tunered]

How can you check headspace with new unfired brass???

 

[Nomad47]

How can you check headspace with new unfired brass???

You can't. And a go gauge made of steel is best.

 

[mr45man]

Your fired brass should be between 0 and 001.
Don't know how it ends up at 004?
On my bench guns ( bolt) i go for 0 head space, running each case through the action.
The tight ones go through the sizer again with a .001 feeler gauge under the case.
004 is working the brass unnecessarily
John H

 

[Tozguy]

Bench,
Your method gives you an idea of the headspace for the FL die setting you are using. It is not clear in your post if the fired cases were FL sized or not. If you want to know whether your cases can be sized less just use the bolt feel approach. Sometimes a mere .001'' is enough resizing to get easy chambering. The tape method is not fine enough and serves no purpose when you are reloading your own ammo. Resizing by as much as .004'' is excessive in my books.

 

[bench]

Tozguy
I have not as of yet FLS the test ammo I shot yesterday I will check shoulder bump and compare it to the zero fired brass just to see the difference.I will also check head space at the bolt face.I would think that the bolt headspace should have been different between the zero fired(FLS) and once fired brass but they both still seemed to be the same.I will recheck both and report my findings.
Thanks

 

[Beau]

You cannot use masking tape to check the headspace on bolt action rifles!

That only works on actions that have little or no camming power, like a FAL. Bolt actions will simply crush the tape. You must use metal shims, gauges or fired brass.

 

[bench]

Beau
you are correct about tape crushing I am very careful about any pressure applied to the bolt but I do have some extra feeler gages and will cut some shims from those to fit the bolt head.
Thanks

 

[BoydAllen]

New brass has quite a bit of room to expand, even in a chamber with minimum headspace. I think that what you need is an attachment for your dial caliper that allows you to compare the distance from a point on case shoulders to their heads, to determine if you have your FL die set properly. I do not recommend using bolt feel to set this. The tool that I like is sold by Hornady, and comes with attachments for various calibers. It used to be made by Stoney Point. Here is a link. http://www.hornady.com/store/Headspace-Gauge-Kits/
You can probably get it cheaper somewhere else. When I am setting up a die, I like to have a case that has been fired more than once, with a warm to hot load, having only been neck sized. That way It will have expanded to its maximum shoulder to head length for that rifle's chamber. I figure my bump from that. When you measure a fired case. be sure to reseat the fired primer well below flush, or remove it with a punch, before taking your measurement, because it is easy for a slight crater to throw your measurement off. Generally, if you are careful setting your FL die, you won't have any problems with headspace. The trick is not to just run the die down till it touches the shell holder and in doing so, set the shoulder back too far. If you are on a tight budget, you can use a pistol case as a kind of improvised gauge to take these measurements. Just decap it, and put it over the neck of the rifle case so that its mouth is resting on the rifle case's shoulder, and measure from the head of one to the head of the other with your calipers.