Got some velocity data on the Hornady 123gr SST, and the Tula 124gr FMJ, using the Magnetospeed chrono.
16" barrel, carbine gas system, 75F.
Hornady 123gr SST:
2346
2372
2388
2382
2363
average: 2370
Tula 124gr FMJ:
2409
2424
2464
2481
2442
average: 2444
Thanks for posting that. Interesting to see the Tula is faster (and by that much!) than the Hornady; my impression of Tula in other calibers the few times I've tried it has been that it was somewhat underpowered.
Just as an interesting comparison (not a "mine is better than yours" thing at all), that Hornady 123gr load is running almost exactly the same speed as the 123gr ELD-M handload in my 12.5" 6.5 Grendel. That's with re-formed 7.62x39 brass too, lots of similarities in those loads except for the barrel length.