i got some ammo given to me, its 125 gr lead round nose bullets, with 5.5 gr of herco. is that high pressure? is that safe to shoot in my hi power? will it lead the barrel? i though herco was a shotgun powder.
If it is reloaded already I wouldn't shoot it, shooting reloads that someone gave you isn't a good idea because you do not know 100% if it was reloaded properly. An older Alliant reloading guid lists Herco and 6.2 as a max load for 9mm with a 125 gr Lead round nose so you should be fine but the manual I looked at does not have a starting amount. You can go online and find it through Allient or others.
As far as the lead bullets Hi Powers are fine to shoot lead out of although sometimes with the friction of the rounds going down the barrel you might have a minor amout of smoke. Not like a black powder round or anything but lead is a little dirtier than jacketed.
I would not shoot it, but that is only based on the "someone gave me these reloads" aspect and not any of the other actual data you presented.
I was at the range a while back and a guy was having issues with his reloads and asked me if I was shooting a 9mm. I said no, only 40 & 22 today. He said, oh, I wanted to see if these rounds would malfunction in your gun too
My thought was, there was no way I would shoot someone else's reloads, let alone that they openly admitted they were having issues with them in their own gun.
Another person on the range volunteered to try them... I was amazed.