I decided to bring my old mag back to life, I have kept it in a suitcase for 15 years.
I recently bought an X-valve and ULT
Actually it is a real job. The lessens from mothers to daugthers in child birth are less and less, so there are people that do bridge that gap of knowledge.
The easy answer:
If you have multiple guns, but want one tank, go with whatever reg runs at 800psi.
I do not care for the SHP