COL Needed

[Lambo]

.223/5.56mm, Bullet:.224 69gr Nosler Custom Competition BTHP Barrel Length: 20in Barrel Twist 1 in 8
Note:
IMR/Hodgdon shows 2.235
http://data.hodgdon.com/cartridge_load.asp
Winchester shows 2.120
http://data.hodgdon.com/cartridge_load.asp
Lyman 48th, Page 145 shows, 2.260
Anyone know for sure?

 

[Ol` Joe]

Different bullets often require different seating depths. The Nosler bullet you are choosing will change the result/pressure at the same OAL that the others are seated to.
When one finds no seating depth listed it is generally seated to max SAAMI lgt. If the COL is listed, that lenght with that bullet are needed to make the data valid, changing any part changes the result. I would seat to the longest lenght the rifle will allow and still feed/function and work up from there. Nothing in the books is cut in stone, not OAL, not powder charge, velocity you will get, nothing!