Yes the 75 gr BTHP Hornadys and 77 gr Sierra Matchkings are loaded to magazine length. I have used both in LC cases with CCI 41 primers and 24 gr. of RE15, which is almost a universal load that works well in every rifle I've ever shot it in.
Concur with the above. I have a 1:9 barrel and well, it didnt shoot as well as I had hoped, dropped down to a 69 gr from wideners and have not looked back... although the coyotes are checking their six.
I load these to mag length in my 18" WOA barreled AR. 24.0 gr RE-15, Win or CCI primers, and Prvi brass shoots 0.5-0.75 moa out to 300. That's about as far as I like to take them though; out to 600 they lose it. 600+ I use the 77gr SMK which handle much better.