I may have missed this info... but what barrel length is your rifle ?, what twist ?
And a little more specific info please. Load details,brass ,primer,OAL and rifle details, please.
FWIW... here is some velocities from the 62gr-69gr class of OEM ammo.
62-69gr
Brand and headstamp on brass..............................16 " Velocities ( FPS )........20" Velocities ( FPS ).........Comments......,,,,,,,,,,,,,,, NC means NATO CROSS
AMA, 62gr M855...............NATO AMA 12..........................Av. 2889 , ES 31.........................Av. 3005 , ES 42............ Good accuracy for M855
Carl Gustav..62gr .............NATO 12-CG-10.......................Av. 2944 , ES 30..........................Av. 3044 , ES 56.......... Still not sure what to think of this ammo.
This is the Swed. "Green Bullet" Very long for its weight.
Fed. 62gr XM855............ NATO LC 13...........................Av. 2967 , ES 73.........................Av. 3040 , ES 82........... Typical Milspec 2-3 MOA
Fed. 62gr MSR Fusion .223.....FC 13 223 REM...............Av 2828 ...ES 54.........................Av 2918...ES 34............ Short stroked twice.
Fed. 62 FMJ .223 Lead Core............................................Av. 2739, ES 73..........................Av. 2761, ES 34
FNM 62gr SS109..............FNM 91-1 NC..........................Av. 3009, ES 34..........................Av. 3118, ES 44.............Gawd, I miss cheap surplus
GGG 62gr M855...............NATO, 5.56 13 GGG...............Av. 2930 , ES 62.........................Av. 3028 , ES 66.......... Ok, I expected better accuracy.
Hansen / PPU 62gr ..........IK .223R..................................Av. 3004, ES 67..........................Av. 3153, ES 68............
Hirtenberg 62gr SS109....HP .223 5.56............................Av. 2965, ES 71.......................... Av. 3000, ES 68 ...........
Hotshot 62gr......................................................................Av. 2919, ES 83..........................Av. 3057, ES 70
IMI 62gr M855.................TZZ 89......................................Av. 3008, ES 44 ..........................Av. 3192, ES 23.............Very accurate for M855.
IMI 62gr FMJ5.56............IMI 13 2 digits.......................... Av 2964.....ES 60..........................Av 3077....ES 32 ...........VERY accurate for 62gr M855
PMC XTAC 62gr...............PSD 14...................................Av. 2885, ES 38...........................Av. 3051, ES 48...............Both XTAC rounds have changed my opinion of PMC "A"
Turkish ZQ1 62gr FMJ......................................................Av. 2892, ES 38...........................Av. 3026, ES 55
Winc. 62gr M855 ............WCC 88....................................Av. 2944, ES 76..........................Av. 3058, ES 56.............
Nosler 64gr BSB .223 .....NOSLER 223 REM..................Av. 2511, ES 58...........................Av. 2560, ES 44.............Not super fast, "A" grade for accuracy.
SSA 64gr BSB 5.56........SSA 5.56...................................Av.2572, ES 109..........................Av. 2570, ES 68............. Had to drop the hammer twice on one round in the 20"..... "A+" accuracy.
Winc. 64gr BSB 5.56......WCC 13 5.56MM........................Av 2883... ES 62.........................Av 2978....ES 25............ Very good accuracy and speed.
Ultramax 68gr..................SPLIT NECKS ON ALL except for the ONE FULL NECK SEPARATION.............................Granted this is 15 years old ammo and maybe they are better now ?!
Fed. 69gr GMM................FC 13 223 REM.......................Av. 2585, ES 30............................Av. 2780, ES 32............. Outstanding Accuracy.. "A+"
PPU 69gr 223...................PPU 223 REM.........................Av. 2564, ES 34................................................Av. 2685, ES 80.............."B+" Accuracy
In general, the fastest ammo in the same bullet weight was typically NOT the most accurate.... so speed is not everything.
Accuracy is ( IMHO ) just as important as speed.... finding a load that does both is the real trick.