Better bullet for 1000 yards

[NightFisher]

I believe you will find that the 107 bullet will slow down faster than the 123 will and at 300-400 yards the 123 will be traveling faster than the 107. The kiss of death to long range accuracy is where the bullet goes trans-sonic as it drops below the speed of sound. A ballistics calculator should tell you where that is for sure, if you don't have access to one let me know what MV you are getting with each and I will let you know where they go trans-sonic.