I think you are pretty close 4 seventy,

My career spanned over three decades with a major oil company with responsibilities for major million dollar equipment and the correct lubrication of such.

The EP you mentioned means "extreme pressure". This is what you want on a hinge pin as it is a VERY HEAVILY LOADED part upon firing. One needs film strength here for the best of wear/shockload capabilities.

It matters not whether the lube is snow white with "purity" or smells of the essense of rose or even what someone (including gun manufacturers) necessarily passes on as good.

E.P. lubricants worth their salt have a test in the manufacturer's lab called "Timken O.K. load" The number will be in pounds. 50 is good but 70 is way better and few lubes reach 70. That is what I use a NLGI #1 grease E.P. with a Timken O.K. load of 70 or more.......... This will buy you all the lubrication and protection a lubricant can provide.

One should stay away from light oils as hinge pin replacement is not cheap, and that is where the no-shock load capability oils will take you.....

Some of the newer Auto trans fluid have some E.P. additives but not to the numbers mentioned above. If I just had to have oil I would use one of these.

Best, BigRx