And you are saying it is a serious undercharge based on what reloading data? What is the minimum load for a 150gr bullet using CCI #34s and IMR 4895? It is 5grs under minimum using a CCI 200 primer, but that is not the primer I am using.You are going to find that with mag primers the powder will be different. I'll also say again that 37 grains is a serious undercharge and you are running the risk of detonation. FPS is irrelevant, it may be a dangerous load. Start over.
Do you have any data to support the undercharge detonation theory. I will admit I have not looked into it in over 10 years, but last I looked it was a theory that no one had been able to replicate in a controlled environment.