Setting Headspace
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My understanding of setting headspace,when a new barrel is turned and attached, is done with the appropriate GO and NO Go gauges.
These gauges are based on SAAMI specs for the particular cartridge.
My question is, what would determine to be the most advantageous setting for performance; tight chamber (as to base to datum) or loose chamber with correctly fireformed brass?
Would the few .000s make a difference to the plus or minus? As Brass thickness makes a difference, would a longer chamber allow a bit more powder without a pressure penalty?
How would this affect accuracy?
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@mamalukino The short answer is, Travis @ TS Customs is responsible for my chambers. It is a very complex topic, and he's very good at it.
The long answer is that if you have short headspace, you won't be able to chamber standard brass. If you have a long chamber, and it's only long by .005-.010" or something and you're properly forming the brass on the first firing... not much of an issue. However, if headspace is over that by much, and you aren't going through a "forming" step on the virgin firing... it will tear up that brass.
If its too long, it can pose a serious pressure problem and be very unsafe.
@mamalukino said in Setting Headspace:
As Brass thickness makes a difference, would a longer chamber allow a bit more powder without a pressure penalty?
NO... just NO. Definitely NO. Just as above, definitely no because this will promote brass movement in bad places.
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As a general rule you want SAAMI minimum chamber. All brass will be slightly (to grossly) smaller than a minimum chamber when virgin. The less you work your brass, the better it performs. Sometimes you need to set the shoulders back a couple .000s so your bolt closes without losing NPA, I shoot mostly offhand so a slight crush fit Works my brass as little as possible. I’m just killing paper or steel so maximum pressure loads are not often needed. I don’t crimp so I get crazy numbers of reloads from my brass. I’ve been shooting the same 1 case in my 32-40 Ballard for almost 8,000 firings in the last three years.
