hi,  need some  input  on a good load for a 223,  useing a 24 inch stainless barrel,  and  loading Sierra match king  77gr hpbt.   and  useing  TAC powder,  need   load  specs ?  and  what  should finish bullet length be  after  its  loaded  ?

TY

You need to get a reloading manual (Sierra because that's the bullet brand you are using), and work up your load.

Begin loading with the start load (lowest charge listed) and work up watching for pressure signs.

Tac is ok, but a better choice is Re-15 or Varget. Primers, I like Rem 7 1/2's in my precession loads. Win or LC brass.

OAL of loaded round is determined by the mag. So 2.260 is max OAL. Myself, I load to 2.250 to ensure perfect function.

Read the front of your reloading manual, it explains all of this.

Also read the Tutorials and FAQ's at the top of the page.

Welcome to ARFCOM.

http://www.ramshot.com/powders/

SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must
be seen as a guideline only.
The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.
This parameter is determined by various dimensions such as 1) magazine length (space), 2) freebore-lead dimensions of
the barrel, 3) ogive or profile of the projectile and 4) position of cannelure or crimp groove.

Ramshot's loadguide on their webiste lists the 77 gr Nos HPBT bullet...I'd start there.