Primer substitution explained with science

I got this video from a range buddy. It's a high quality video from a professional reloading company explaining that it is SAFE to substitute small pistol primers with small pistol magnum or even small rifle primers. It also discusses primer cup strength and weak springs etc etc. This guy shows all the correct pressure testing data, AND actual range/velocity testing data to demonstrate the safety. It's about 10 mins. long. I'm not expert enough to concur or disagree with this guy, but I thought it was worth passing it on.

https://www.youtube.com/watch?v=NGVRGsoOr6k

J.

I saw that video a while back and so far it's the best presentation I've see on using different small primers. A similar video on large primers would be helpful to many as there is a dimensional difference in large pistol and large rifle primers...

I watched that video yesterday. What it proves is that the substitutions were (reasonably) safe in those specific instances - safe, as in they didn't cause catastrophic failure of the firearm. IMHO, it would be cost prohibitive for any small company to conduct a valid test of this matter. It would require firing many, many thousands of rounds of ammunition in each cartridge of concern to provide statistically significant results. You would literally have to test every single bullet/powder/primer combination possible in several identical firearms (for each cartridge) before the data would be meaningful and reliable. Firing three rounds of a random combination and calling that definitive proof is simply not how real testing is done.

I would really like to see SAAMI or someone comparable conduct such testing and publish the results. In fact, I tried to contact SAAMI yesterday for their read on the matter, but was not able to do so.

Lots of things could be considered "relatively safe" under field expedient circumstances. I don't think we're at that level YET but hard to say what the next 4 years will bring. Knowing and understanding the limitations of the expedients would be paramount to ensuring relatively safe use. Also the condition and/or built in features of the firearm would have a bearing on the safety. A pierced primer in some guns would be an all-round bad day for the shooter.