I don't believe the standard ammunition of the time was loaded to 20,000 psi. If it was not, then I believe the original airweight was designed to fire ammunition of around 16-17,000 psi. That's what I believe. I could be wrong. I have been wrong before. I will, no doubt, be wrong again. If I am wrong, then the manufacturers who told us the guns were not recommended to be fired with a steady diet of plus P ammo are also wrong, or liars, or fools. I don't know. I am left, as before, with the decision that I either follow my own best beliefs and/or listen to those who I deem to be more knowledgeable than I. When I find "responsible" sources who disagree, I must determine which to believe. The factories. Countless articles written over the years. Or, a small number of people who post a lot on the internet and stand in marked disagreement with conventional wisdom. I know what I choose to believe. Others might choose other things to believe. It matters little to me. If I had clear proof that you are correct and I am wrong, I promise you sincerely I would confess my error and thereafter remain silent. In the several years I have followed this debate, I have yet to be convinced that your argument has merit but I don't really want to pursue the debate ad infinitum. Once again, I do not believe the ability of the steel K-frame to digest hot loads has any bearing on the ability of the aluminum J-frame to do the same. I may be wrong. You may be right. We will simply have to agree to disagree. The best to you.