Thread: Testing a conventional approach to load development

"pressure signs" on brass are very difficult to interpret consistently. Many things can create these signs - the hardness/quality of the brass, the sizing/headspace of the ammunition, etc. Some factory ammunition will show ejector marks or sticky bolt lift in some firearms. This .260 in this thread had sticky bolt lift and ejector marks with some rando factory 120gr Federal Fusion ammo I had that I used to get a rough zero.

While these signs may indicate a chamber pressure that is over SAAMI max, they also may not.

You can minimise your chances of experiencing problems by using quality brass, following a good reloading process (e.g. measuring and setting up your FL die for minimal shoulder bump) and thoroughly researching data before loading. Velocity is the best indicator of pressure - if you are getting more velocity than a reasonable estimate based on book max values corrected for your barrel length, you should reduce your load.


There is a reasonable practical safety margin between SAAMI max chamber pressure and the point at which brass will fail, and then higher again - the point at which it will be a problem. This doesn't mean we should eat into that safety margin, it just means that if you find yourself a little over SAAMI max due to variances, you won't die.

If you get indications of excessive pressure with any loading approach, reduce the load.