One sign of excess pressure is loose primer pockets.
If you're loosening primer pockets on the first shot, it's definitely excess pressure and time to back off. In ARs usually I see ejector hole marks (not just swipes, but actual raised circles on the case head) but not always.Those marks can be a sign of over pressure, but the absence of them doesn't mean you're OK.
If a case is reloadable 6-8 times with tight primer pockets, pressure isn't close to max. I consider max where a case is reloadable 3-4 times (assuming no other pressure signs either)
I generally agree with all of that, with 5 loadings as my nominal target.
What I meant by my earlier comment about 5.56 pressure, is that I don't think I've ever seen a direct translation of the NATO standard to PSI...............I've generally understood it was some around 62K, but never really seen in spelled out. Obviouly it must be around 62-63K as that's where Western maxes their specified 5.56 loads for their various powders.
But at any rate, 2750 from a 16" barrel is not leaving much on the table, & IMO, & has got to be at, or very near, max 5.56 pressure level, especially when BH MK 262 is running below 2700 from a 16" barrel...............with a given bullet & barrel, velocity only comes from pressure, given that different powders may have slightly different pressure curves.
What do you want to do, David?
If I was plinking I'd get the cheapest ball powder I could find, like WC844 or 846.
If I wanted to shoot precision type matches, I'd load up on a temp-resistant stick powder like Varget, AR-Comp, 8208, H4895, N140 or even a better ball powder like TAC. You won't know which one is best for your gun until you try it.
I generally agree with that direction too.
MM
