Need to check head space if COAL is correct?

[jackles]

Hi guys,

So after reading two pages on cartridge head space I'm just wanting to make sure I've got my head around this correctly.

When reloading... As long as cases are trimmed when required and you don't exceed the min/max COAL, head space should take pretty much take care of it's self, correct?

I would be checking for all the usual problems like split necks or head separation, but as long as all this and above is as it should be, the shoulder of the brass and head space should be right... Yes?

[Hardcast]

No.

I'm not sure that you are understanding what 'headspace' actually is.

Headspace is the distance between the bolt face and the very start of the barrel, where the shell pushes up to, and can go no further.

In other words the space between the two.

If there is not enough headspace, a shell that had been literally cut in half still wouldn't allow the bolt to be closed.
And, if there is too much headspace, the shell is literally loose (floppy) when the bolt is closed.

A long COAL, can actually hold a loaded round, semmingly tight in an action where the headspace is actually loose, but this is very dangerous
and this is why headspace needs to be checked.

Headspace must be checked by a competant gunsmith.

Hope I explained this right.

[jackles]

Hi Hardcast,

Yes, I get that it "is the distance between the bolt face and the very start of the barrel, where the shell pushes up to"

What I took away from some other reading was that the base of the shell would be against the face of the bolt, and the shoulder of the case should push against the throat.

Like I said above, this implied to me that as long as the neck is trimmed and the case is resized, the shoulder should take care of itself.

But I get what you mean about a long COAL holding a cartridge in place where this could be the bullet creating the fit, not the shoulder.

Cheers.

[Hardcast]

I think I know what you're saying, yes, if the shell has been F.L.S. then trimmed to length, then once it has been shot through your
rifle, then the shell will be fireformed to your chamber, if you only neck size from then on then nothing much will change except a bit of length
which can be checked and trimmed if needed.

If there were to be a bit of excess headspace, (within tolerence) the shell may grow a little.

If you F.L.S them every time you reload, then there is the possibility that the shell will be slightly undersized (theoretically) according to your chamber.

Sorry starting to babble.

[jackles]

Sorry starting to babble.

It's all good babble so far

[jeebo]

Is headspace something you should get checked every couple of years or something?

Does it change as things wear or is it more if there is a problem to start with it just needs to be fixed once?

[5Tom]

I'd say it would be good to have it checked on a rare occasion.
To my knowledge, if the case is trimmed and made to SAMMI spec and you feel resistance when closing the bolt or the case is loose on a closed bolt, you have a headspace problem.

At least that what I've gathered.

[Kipper]

Nah, it's not a regular maintenance thing.

If all is working well, leave it at that. I wouldn't be spending hard earned cash to have a smith check it once a year or anything.