Best Way Or Tool To Check Headspace?

[MOOSE 4 GOD]

[I][COLOR=darkblue]How important is headspace and how do you make sure you do not have excessive headspace? What is the best way or tool to do this with? Foster makes 3 types a go guage/ no go guage/ and a field guage. What is the differance? LE Wilson and Stoney Point makes what is called Cartridge Head Space Guage for a lot less. I'm confused Anyone who can clear this up in laymans terms for me I will truly owe you one.

Thanks so much for your time
Benny Moses

[royinidaho]

Benny,

Hopfully Rocky will respond to your question. He is a pro @ descirbing simple but complicated things.

If you're speaking of the 7mm REM, the cartridge head spaces on the belt. Beltless cartridges head space on the shoulder.

It all has to do with case stretching when shooting. Sizeing too much creates too much head space. And sizing too little, not bumping the shoulder back once in awhile creates too little head space. Or is it the other way around.

Like I said, Rocky's the the man to answer.

[BILLY D.]

go to stoney points web site. they have the tools you are looking for there and an explanation for each.

[MOOSE 4 GOD]

THANKS Roy & Billy: This has helped a lot. I didn't think to go to a web page. Sometimes I can't see the deer for the trees or something like that. Any way I'll go and do some research and again thanks a lot for the help.

Benny



MAY GOD BLESS AMERICA AND OUR TROOPS WHO PROTECT HER!

[Ol` Joe]

Stoney Point is definatly the easiest. Here`s their web site

http://www.stoneypoint.com/headspace_index.html

Midway and Sinclair offer them if you decide to try one.

[MOOSE 4 GOD]

Thanks Joe:

Midway was where I saw their guages. Just didn't think to go there. I left them a message about my 7-30 Waters. In their book it shows the bushing for the 7-30 but not the case for the overall length guage. I will buy this set up as soon as I here if I need to send them Stoney Point a couple of my cases. Any way they have it all for my 7mm. Thanks again for the help.

Benny" THE MOOSE" Moses

[Rocky Raab]

For Moose or anyone else...

Headspace is simply the "fit" between a properly dimensioned cartridge and a properly dimensioned chamber. If there is too much room in the chamber (or too small a cartridge)when the cartridge fires, the brass will be unable to expand enough to contain the pressure, and will rupture. Hot gas, burning powder and metal fragments fly out everywhere. The gun may be ruined - not to mention your handsome features.

So excessive headspace is very bad, indeed.

Too little headspace is bad too, but you can't chamber a cartridge so it's less dangerous.

Headspace is set by one of three things: the thickness of a cartridge rim or the distance to the top edge of the belt, or (on cartridges with neither rim nor belt) the distance from the base to a point about halfway up the slanting shoulder.

Obviously, the first two methods are pretty simple to measure and set in the gun. But rimless cartridges are the very booger for setting headspace because the measurements are so difficult and elusive (Halfway up the shoulder? Measured from where on the rounded transition from the case wall to where on the rounded transition to the neck? See?)

So comebody invented the headspace gauge. It's simply a carefully machined steel device that looks like a cartridge with no neck or bullet. It comes in two or three-piece sets. The one that's sized to be normal is called the "go" gauge. If you can insert it in the chamber and close the bolt all the way, you're "good to go". The next one is just barely too big to meet the agreed-on dimensions for that cartridge. If you can chamber that one, you have a bit too much headspace, and it's a "no go". Finally - for wartime expediency - there's a "field" gauge. It's grossly oversized. In the field, an armorer would pass any rifle that would not close on the field gauge, and reject any that would. (Hey, slightly excess headspace is dangerous, but this is war!)

Today, some sophisticated shooters don't settle for a pass-fail headspace test. They want to precisely adjust the size of their cartridges to exactly fit their gun's chamber. So you can buy tools like the Sinclair gauge, which allows you to calibrate your sizing die to create cartridges that match your gun's chamber.

Note that now we've done a 180-degree shift here: in the past, we used a gauge to fit the rifle to standardized cartridges. Reloaders are now adjusting their ammo to standardized rifle chambers. Understanding what we're trying to fit to what is critical in this discussion. Just say "headspace" and it's easy to be confused.

Which is just where we came into this, right?

[MOOSE 4 GOD]

Thanks again Rocky:

So let me ask one more Question. I'm loading a 7mm Rem Mag in a new TC PRO HUNTER. I only neck size or at least that is all I ever done for the last 18 years in a bolt action. My question is as long as I check the OAL of my brass and it goes in and out of my barrel with ease do I even have to worry about the word HEADSPACE?

Thanks
Benny

[Rocky Raab]

Not really. Neck sizing is probably the better option for belted cases - until the cases get hard to chamber Then you'd have to full-length size them again.

The danger with belted AND shouldered cases is the ease with which one can push the shoulder back too far while sizing. Then, even though you haven't affected the "official" headspace fit (at the belt) you create a dangerous undersize condition at the shoulder. When fired, the brass has a hard time expanding into all that airspace and can rupture.

But most sizing dies are designed and machined to avoid the biggest part of that problem, so even that caution is "no biggie."