Estimating Chamber pressures???
- Thread starter northern skies
- Start date
There is a software program called quickload that can be purchased.And since the calculation can't take into account variations in chamber and barrel dimensions,powder lots,or cartridge case variations,the resulting estimated pressures and velocities are very rough.
Like Stubblejumper said quickload is a guideline.
Pressure trace is available, it is actually pressure testing equipment.
Your best bet is a chronograph.
When your speed for a particular bullet/powder/primer combination starts exceeding what is printed in the manual you are starting to get into dangerous territory.
Chronograph and common sense are all you need.
If your primer craters, or falls out...watch out!
If brass starts expanding to the point where you get sticky extraction, heavy ejector marks or shiny rings close to the web...watch out!
Pressure trace is available, it is actually pressure testing equipment.
Your best bet is a chronograph.
When your speed for a particular bullet/powder/primer combination starts exceeding what is printed in the manual you are starting to get into dangerous territory.
Chronograph and common sense are all you need.
If your primer craters, or falls out...watch out!
If brass starts expanding to the point where you get sticky extraction, heavy ejector marks or shiny rings close to the web...watch out!
Then again you might already be exceeding the SAAMI pressure for the cartridge before reaching the velocity printed in a manual.Or you might exceed the printed velocity and still be under the SAAMI pressure for the cartridge.Since the posted velocities vary considerable from manual to manual,even with identical components and barrel lengths,which manual do you choose to use as a reference?Even the use of a chronograph can't provide accurate estimates of chamber pressures.If you see any signs of pressure such as sticky case extraction,brass extrusion,excessive case head expansion,or primer pockets becoming loose after a few firings,be aware that you are likely exceeding the SAAMI pressure for the cartridge.If on the other hand,you see no visible pressure signs,and the primer pockets are still tight after five or six loadings,your handloads are very likely developing safe chamber pressures.
