Headspace question

[Danny Treacy]

I can't quite get my head round the concept of headspace and how to measure it.

Is it necessary to get a headspace gauge for my rifle and for the cartridge or is there another way to do it?

i ask as my Lyman book doesn't list a headspace gauge as a essential piece of equipment for reloading but the in later chapters it advises to use one.

What do you guys do?

​Atb.

 

[Brithunter]

Head space is set up with the barrel fitting and chamber cutting and unless you have really abused the rifle and or it has faulty hardening then actually finding a rifle with excessive head space is rare.

Head space is the distance between head of the case and the datum point on the shoulder in rimless cases.

I do own a couple of sets of head space gauges but only because they were needed for the fitting on new barrels and re-chambering on one of the barrels. As one was a .303 which is not so common nowadays it seems and the smith did not have the gauges so I brought a set of Disc gauges from the US in the correct British standards and not the spurious SAMMI ones. The others are in 280 Rem and the Go was used in the cutting and fitting of the 280 AI chamber.

I have never used nor needed head space gauges for any of my hand loading.

Somehow I get the feeling that some companies are just trying to sell more of their tools.

 

[Sinistral]

I'm not sure what experience you have Danny, but think you're confusing 'headspace' with 'overall length'(OAL).

That's understandable because 'overall length gauges' such as Stoneypoint/Hornady are advertised as 'headspace gauges'. If you use this link it might help:-

http://www.thestalkingdirectory.co.uk/search.php?searchid=2184211

A lot of reloaders assume that their initial production which doesn't chamber slickly, or jams the action up, is wrongly 'headspaced'. That's rarely the cause, but is just cases fired in another rifle (with slightly different chamber dimensions) which haven't been resized enough in the critical base area. On other occasions the round is set too long i.e. the bullet isn't seated deeply enough so jams in the rifle throat when closing the bolt. Sometimes it's factory ammunition with one or both of these characteristics e.g. the odd batch of PPU which turns up.

I use nothing but once-fired cases which are full-length resized down to the shellholder. This is usually the best course for Tikka or Sako rifles. On 2nd firing just neck-size (Lee Collet Dies are good for this) and then there can't be any 'headspace' worries. Just concentrate on getting the OAL right. It's definitely worth buying an OAL gauge.

 

[Danny Treacy]

Thanks for the info. Yes I am very new to reloading so confused as to what is actually needed to ensure safety.

My Lyman reloading book stresses that if there is too much headspace then the gasses could blow out dangerously.

I understand the concept of OAL I think. Couldn't I just use a calliper to measure a round I make up, without powder in it?

cheers.

 

[MarinePMI]

For COAL yes, you can. For actual headspace measurements of the case, no. You'd need something to accurately measure the shoulder to case head dimension, which a caliper alone will not.

You're a little too concerned with this concept (and I do not intend that as a slight against you). Just follow the book's instructions and load some ammo. Don't be overwhelmed by all the subtleties, just load the ammo as instructed until you get a better understanding/feel for the process.

JMTCW...

 

[Muir]

Agreed. Don't brain work this too much.
Do the basics. Use starting loads. Shoot.~Muir

 

[Danny Treacy]

Ok great, like the idea of keeping it simple, I've already spent more money and time on this than I would like without shooting a single round!

​cheers.

 

[JMS906]

Thanks for the info. Yes I am very new to reloading so confused as to what is actually needed to ensure safety.

My Lyman reloading book stresses that if there is too much headspace then the gasses could blow out dangerously.

I understand the concept of OAL I think. Couldn't I just use a calliper to measure a round I make up, without powder in it?

cheers.

Don't rely on a single source, in this case your Lyman manual. It's a good idea to have at least two manuals. If something is unclear in one, it may be better explained in another. The Hornady and Vihtavouri manuals are worth having (either of them). Also, have a look on the powder and bullet manufacturers' websites and place like Sinclair International (and many others) for the reloading process. Of course, you can also ask further questions here.

Providing you have bought a rifle in good condition and you are using decent reloading kit (and setting it up as per the instructions) you need have no concerns about headspace at this stage.

--JMS

 

[Brithunter]

I also think this "danger" is over stated. Having seen the result of a wrong cartridge , in this case a .308 being fired in a .308 Norma Magnum chambered rifle, apart from the shot being very low and the case coming straight walled no damage was done.

This incident happened due tot eh vendor not checking the rifle properly and selling and entering it onto the shooters FAC as a .308. Well it was a .30 calibre I suppose just chambered for a magnum cartridge. the shooter saw .308 on the barrel but the scope obscured the Norma Mag bit.

​Now that is a case of hugely excessive headspace.

oh it was the range chap who had offered to spot for the shooter who happened to look down as the case was ejected and saw the straight case and though it was a case separation so stopped the shooter firing again.

Using the wrong powder is more dangerous IMHO as I have seen several guns that have been destroyed by this.

 

[deershooter]

Strip the firing pin out of the bolt, get a resized case or loaded round cover the back of the case with one layer of good quality masking tape scratch round the base with a stanly knife blade to leave a circle of tape on the base of the case load in to the chamber and carefully close the bolt .

If the bolt closes easily replete with more layers of tape ,my tape measures about 3 tho it's not scientific but gives you an idea .

One thing to mention is that this needs to be a new case or factory load the headspace on a once fired case without the shoulder pushed back will have changed.

Deershooter