Thread: 7mm PRC speeds & pressure

7PRC articles & reviews indicate some impressive potential in terms of muzzle velocity with 180g pills clocking 2950-3000 fps out of 24in bbl. But also comes at high pressures at or close to 65,000 psi. To date I’ve always regarded 63k at max pressure in magnums & larger capacity calibres. The SAAMI specs for 7PRC also state 65k psi so I’m sure this is safe max in suitable modern actions. My question is how does your average hand loader measure psi? Is it measured directly or indirectly via apps like GRT. Some good info & reviews published in NZ Hunter mags. I’m interested to learn how the pressure readings stated were made. @GredD are you able to comment please.

Oehler 43 and their newer model, and the pressure trace 2 both use piezoelectric strain gauges that are glued to the exterior of a rifle barrel.

The gauge deforms and creates a change in electrical resistance, which is then measured and converted to a strain value to show rifle chamber pressure when a rifle is fired.

The average handloader doesn’t. He or she can only compare velocities against factory specs and look for signs of excessive pressure which may or may not be obvious.


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I have a Kolbe p max, it is one of the rare instrument other than the oehler that could relyably read pressure for the average consumer.