77grn hunting/match loads for 18 in ar 15

[Unclesmack]

So I just got done building a precision AR in 5.56 and im trying to find a factory load the rifle likes but im finding it hard to find heavier ammo other than hornady. Black hills is sold out everywhere. So ive decided im going to start reloading my own hunting/match ammo. The bullets I choose need to do both interchangeably if possible. Need some suggestions on bullet seating depth, bullet selection, powder etc. not super new to reloading but ive never reloaded for a semi auto platform.

 

[Gustav7]

I'd recommend trying IMI Razorcore, you can get it from SG Ammo.

For reloading, I wouldn't worry about seating depth, just load to ~mag length (2.25-2.26).

I shoot 77gr Sierra TMK's, but am redoing my load development with Hornady 75gr HPBT to save on bullet cost a little and do just get some more experience playing around with my AR load development (sometimes its not always easy)

Powder, I have used Varget, TAC, RL15, and XBR 8208. For me TAC was good accuracy and the best velocity but just not consistent enough in my rifle across differing temps. I only want one load for all year, so switching to XBR 8208 and sticking with that. Just loaded up a couple ladder tests with XBR 8208 and will be doing those soon hopefully.

For me, I don't have a ton of experience doing load development for precision rifles, so I've done it over and over again to try and just get some experience and try different things.

Do you have a chronograph?