looking for BC for M262,M855,M193

[TREE FROG]

Guys looking for some info ,looking for the BC for the following ammo and muzzle velocity for
Mk262
M855
M193
For use in my SPR I know the best way is to use a chronograph for the muzzle velocity but I don’t have access to one and I’m trying to get the info required to develop my data book thanks for your help V/R TREE FROG

SPR spec 18"stainless barrel 1/8 twist with surfire FA566 flash hider,

[Failure2Stop]

Here is what was given to me by guys that test mil guns. I cannot say for certain that they are correct, but I have seen nothing to cause me to doubt them.

G1 BC
M193- 0.243
M855- 0.304
Mk262 Mod1- 0.340

I don't have MVs for them with an 18" barrel.