FWIW 77s are kind of anomaly. They are lighter than 80s ( all the old bullets I know nothing of the newest bullets) so we think they should go faster but due to bearing length and intrusion into case capacity vs mag length, they aggravate us on paper numbers...
I use a lot of 77's, mostly all still SMK's as they are consistent & accurate even though there are a few 73 grain bullets today with better BC's today, the SMK's are just a known commodity & dependable.
As I said in another post, Black Hills MK-262 is nominally 2750 FPS, so my goal with everyday use 77 gr ammo is to come as close as possible to that velocity with acceptable accuracy.
Having said that, some powders, like Varget, either don't get to that velocity level or their sweet spot for accuracy is somewhere below the 2750 number to & that's OK depending on the purpose & use of the ammo.....................not everything has to be an 800 or even a 600 yard load.
I also shoot a lot of 69 grain SMK's & TMK's, & to 500 yards, there's really not much performance difference from the 77's & in some cases, the 69's are more accurate & maybe even easier to get to shoot well.
My goals & objectives with some ammo is not the same as all, & 500 yards covers most of my needs by a good margin; everyone has different goals of what they want to do.
