Just thought id ask guys, what BC are you guys plugging in to your ballistic calculators for the 39SBK. I know that Sierra advertise 0.287 above 3600 ftps, and I know that this is well OTT. I have Chronoed my bullets at various distance and have come up with a BC of 0.251 but im still struggling with windage etc. Its as if I am always underestimating the wind or that the BC of the bullet is more like 0.230.
Been taking mine out to mid ranges, around 600 yards. I use Strelok Pro and 0.242 as my BC. It seems very close on elevation and windage is normally ok but it only take a small gust of wind to completely change such a light bullet. My rifle only has a 20" barrel so my FPS is down to 3435 so that might be why .242 works for me.
How I got .242 was not very scientific I looked up the BC
Between 3400 to 2800 = .255
2800 to 2300 =236
.255 + .236 = 491 .491/2 = .245 less a bit for the slower speed before it hits the target, hence .242
247sniper wrote:Does nobody shoot .204's long range using ballistic programs?
Not on a regular basis. But I have shot mine at 1000 yds, just to see what I could do. Granted, I picked calm days (< 5mph winds). I used Strelok and it got me consistent hits on a standard IPSC target. Had to chuckle at the lack of serious markings on the steel, though. If it weren't for the paint, I wouldn't know there was a hit!
Savage 12 FCV .204 Ruger
Viper PST FFP 4-16x50
======
"A fear of weapons is a sign of retarded sexual and emotional maturity" Sigmund Freud.