Magnum Primers needed???

[denton]

From CCI's web page:

Q: What's the difference between a "standard" primer and a "magnum" primer?
A: A magnum primer provides a longer flame duration, a higher flame temperature, or both. In some primers (the CCI small pistol primers, for example) the magnum primer may have a thicker cup to better handle higher pressures. Use magnum primers only where recommended in published load data. Substituting a magnum primer for a standard one without a charge adjustment will nearly always increase pressures. We use Magnum primers in data development with many ball propellants, and with very large-capacity cases. They are also a plus when you are shooting in temperatures below 20 degrees F.


None of the loads I have tested with CCI 200 and CCI 250 primers have shown any statistically detectable peak pressure difference. That does not mean there isn't one, just that there isn't always one, and my small sample hasn't found those cases yet.