Thread: Is it Pressure or Powder Capacity?

Originally Posted by Hermitage

The way I am understanding it from the Speer manual and the Youtube video @Seventy Six above linked (listen from 4:30-6:10 minutes), is that barrel erosion depends on pressure which increases the core temperature of the gases.

Video "It's not necessarily the powder charge,....the bullet weight,....the amount of powder we are using....it's the pressure."

So to answer your questions @grandpamac:

No...more powder does not equal more erosion if pressure is kept low (ie 55,000)
No...a smaller bore does not equal more erosion if pressure is kept low (ie 55,000)
Yes higher pressure equals more erosion (ie 65,000)
Unsure about the answer for the shorter neck question.

Greetings Hermitage,
I had a quick dig on the internet and came up with a couple of barrel life calculators including Mikes Spreadsheet. The input variables for the calculators are:
Projectile diameter.
Powder charge weight.
Powder heat potential.
Pressure.
Projectile coating if any.

The powder charge and heat potential determine the amount of heat available. The pressure determines the way the heat is applied to the throat and the projectile diameter determines how much steel that heat is applied to. So rather than pressure alone driving erosion it is a number of factors. If pressure only was the culprit then the .243 and .308 would have the same life, or .25-06 and .270 for that matter. This is definitely not the case.
Regards Grandpamac.