55gr nosler B.C?

[strud34]

i put this in the Varminter & Hunting Forum guess its the wrong place so i put it in here

Hi was looking at some light 6mm varmint bullets and the B.C on some don't look right how accurate is the clams of the manufacture?

Was looking at the nosler 55gr with a b.c of 276 and then look at the 58rg vmax b.c 250. The vmax has a bigger boat tail and is 3 gr heaver than the nosler and just looks more streamlined but the nosler has a much higher b.c.
Even the 65gr vmax only just has a better b.c 280 with all that extra wight.
the burger 65 gr Match BT Target b.c 270 .
so why it the nosler got such a high b.c for its wight?

 

[Fat Albert]

Factory BC's are like TV reality shows. Its all about marketing. The minimum that you would need to check the BC of a bullet(in you gun) is to have a Chromograph and a balistic program. If you know the muzzel velocity of the load with that bullet and have the gun sighted in at a set distance, say 100yards and then shoot it at a different distance (300) you can check the BC on the program by the amount of drop at the longer distance. If the program says that the drop should be 3" and it is 4" then the BC of that bullet is less than stated. Just keep lowering the BC amount on the program till it shows a 4" drop and that is the BC on you rifle(give or take). An anal set up would take 6 chromograps, 3 pairs set at 3 different distances to find the average speed at each distance and be able to run the same bullet over all 6 at one shot. You would then need a program to enter that data along with air temp-altitude-air pressure. But that would be the BC for that one bullet. Its all about averages.