24 for velocity is my thinking also. http://www.accuratereloading.com/223sb.html Barrel cut from 22" down to 10" with load and velocity datas.
[SIZE="3"][B]Armalite M15A2 Carbine
16.5" 1:9 Chrome Lined barrel[/B]
69 Sierra 24.5 grains AA2520 S&B cases WSR (Brass) OAL 2.25"
23-Mar-05 T = 65° F
Ave Vel =2643
Std Dev =34
ES = 158
Low = 2559
High = 2717
N = 25
very good groups
69 Sierra 24.5 grains AA2520 LC mixed cases WSR (Brass) OAL 2.25"
23-Mar-05 T = 65° F
Ave Vel =2629
Std Dev =34
ES = 92
Low = 2594
High = 2686
N = 10
good group but 3 pierced primers!
[B]M15A2 Armalite 20" 1:8 Stainless Wilson Barrel [/B]
69 gr Sierra Match 24.5 grs AA2520 wt'd WCC91, WSR, OAL 2.250"
11-Nov-97 T = 48 °F
Ave Vel =2754
Std Dev =43
ES = 191
Low = 2666
High = 2857
N = 15
69 gr Sierra Match 25 grs AA2520 wt'd WCC91, WSR, OAL 2.250"
11-Nov-97 T = 48 °F
Ave Vel =2818
Std Dev =14
ES = 44
Low = 2789
High = 2833
N = 10
69 gr Sierra Match 25.5 grs AA2520 wt'd WCC91, WSR, OAL 2.250"
11-Nov-97 T = 50 °F
Ave Vel =2887
Std Dev =14
ES = 44
Low = 2863
High = 2907
N = 10
[B]Compass Lake Flattop, 24" 1:8 Kreiger Barrel [/B]
69 Sierra 24.0 grains AA2520 LC mixed WSR (Brass) OAL 2.25"
2-Jul-04 T = 80° F
Ave Vel =2928
Std Dev =29
ES = 99
Low = 2861
High = 2960
N = 10
69 Nosler 24.0 grs AA2520 thrown lot 9595 WSR(nickle) LC86 OAL 2.25"
10-Jan-14 T = 49° F
Ave Vel =2829
Std Dev =65
ES = 177
Low = 2722
High = 2899
N = 5
excellent group
69 SMK 24.25 grs AA2520 thrown lot 9595 WSR(brass) LC90 OAL 2.25"
10-Jan-14 T = 49° F
Ave Vel =2817
Std Dev =22
ES = 71
Low = 2781
High = 2852
N = 18
69 Sierra 24.3 grains AA2520 LC mixed WSR (Brass) OAL 2.25"
22-Aug-03 T = 72° F
Ave Vel =2870
Std Dev =13
ES = 42
Low = 2845
High = 2887
N = 12
69 Sierra 25.0 grains AA2520 WCC91 WSR OAL 2.250"
21-Jan-03 T = 48°F
Ave Vel =2898
Std Dev =49
ES = 145
Low = 2821
High = 2966
N = 14
a few pierced primers[/SIZE]
Noooooice...Yes, congrats on your purchase. We will need pics.
These are my two small caliber critter-gitters.
Top is Rem 700 in 221 Fireball with a Boyd's stock (20" fluted barrel, Redfield wide field of view 3-10 scope).
Bottom is a Kimber Longmaster Classic in 223 (24" fluted barrel, Zeiss Conquest 4-14 scope).