So I'm accumulating all the small bits and pieces to round out my reloading kit and I'm just wondering what exactly these case length/ headspace gauges do, and if their worth investing in? I'll be reloading some hunting and target rounds in 30-06 and eventually moving to other calibers. Hopefully somebody on here can educate me as to how, even after trimming my brass to the correct length, I can run into headspace issues? Does it have to do with the shoulder of the case moving forward as it stretches out and interfering with the cartridge chambering correctly?
Lyman Case length/ headspace gauge?
- Thread starter pshore
- Start date
Them case length gauges show you whether your rounds will chamber nicely in any SAAMI chamber.
This does not mean the rounds won't chamber your gun. If resizing the neck only the rounds will likely chamber your gun just fine but likely not others.
Now if you trim the case perfectly but you don't resize it correctly you may have issues.
As in, the shoulder is not bumped back enough or the case is too thick towards the webbing.
This does not mean the rounds won't chamber your gun. If resizing the neck only the rounds will likely chamber your gun just fine but likely not others.
Now if you trim the case perfectly but you don't resize it correctly you may have issues.
As in, the shoulder is not bumped back enough or the case is too thick towards the webbing.
Trimming usually won't affect headspace, since you are trimming the case mouth, which will affect overall length. In the case of the 30-06, headspace is measured from the base to a reference line (referred to as a datum line) partway up the shoulder. Trimming would affect the headspace of cartidges like the 45 acp and 9mm parabellum, which rely on the case mouth for headspce control.
Rather than an case length gauge, I would get a dial caliper, which gives you a numerical measurement, and not just a pass/fail comparison of a maximum length. The caliper would also be useful in determining overall cartridge length, and with a few other add-ons, the length to the ogive of the bullet
Some guys like the digital calipers, as they are really easy to read, and often measure both Imperial and metric dimensions.
Rather than an case length gauge, I would get a dial caliper, which gives you a numerical measurement, and not just a pass/fail comparison of a maximum length. The caliper would also be useful in determining overall cartridge length, and with a few other add-ons, the length to the ogive of the bullet
Some guys like the digital calipers, as they are really easy to read, and often measure both Imperial and metric dimensions.
Headspace is a rifle manufacturing tolerance that allows ammunition from all makers to fit in the chamber. Headspace gauges are used to determine if a rifle's headspace is within tolerance. Cases do not have headspace.
Like OldDude says, trimming has nothing to do with headspace on your .30-06 cases. Bottlenecked cases like the '06 tend to stretch and need to be trimmed periodically(isn't required every time. Only as required when the case gets over the max case length given in your manual. 3.494" for an '06.) Fortunately, trimming pistols cases like .45 ACP is rarely needed. When you trim, you will need to chamfer and deburr the case mouths too.
You do need to check the lengths every time(especially for any semi-auto). A case length gauge is really a go/no-go gauge that makes checking length a whole lot faster. The Vernier calipre(digital is faster to read. And plastic will do.) can be set to that 3.494" and used as a case length gauge. No need to buy a case length gauge.
Like OldDude says, trimming has nothing to do with headspace on your .30-06 cases. Bottlenecked cases like the '06 tend to stretch and need to be trimmed periodically(isn't required every time. Only as required when the case gets over the max case length given in your manual. 3.494" for an '06.) Fortunately, trimming pistols cases like .45 ACP is rarely needed. When you trim, you will need to chamfer and deburr the case mouths too.
You do need to check the lengths every time(especially for any semi-auto). A case length gauge is really a go/no-go gauge that makes checking length a whole lot faster. The Vernier calipre(digital is faster to read. And plastic will do.) can be set to that 3.494" and used as a case length gauge. No need to buy a case length gauge.
I have a set of digital dial calipers that I'll use to check the Case length before and after trimming. I have a bunch of once fired brass that I've sorted by manufacturer as well as whether they need to be trimmed or not. I think I understand a little more about headspace now, but I'm still wondering if the Lyman case length, headspace gauge is a worthwhile investment to check my finished rounds, more like quality control I guess?
