Cheddite Primer pressure spikes

[J.B. Books]

I will continue to watch the thread and hope the OP provides that info. I doubt he is making up a story. One way or the other it would be good to know the facts.

Originally Posted by Frank Srebro

On that Trapshooter thread; many replies but so far the OP has been reticent to reveal the lab or source that did the pressure testing. ?????

[Pa SxS]

I asked Alliant a couple of years ago about primer swapping, specifically swapping primers in 20 and 28 gauge guns. I wasn't concerned about 12 ga. because my pressures were in the 6k to 7k range. I asked them if using their published components, would it be safe to substitute only the primer? They didn't have the specific primer I wanted to use but they said they tested all the popular primers in their published loads and the highest pressure spike they observed was 2,500 psi. SAAMI service pressures are 12,000 psi for 20ga. and 12,500 psi for 28ga.

So, if you want to substitute a primer into their published recipe, add 2,500 psi to their data and if it's below SAAMI limits, you can substitute. They advised me not to do it in 28 ga.