SmallCaliberCentral

Hi guys,

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.

Any ideas guys or could anyone help please


Thanks guys.


Steve.

That number agrees with Shooter. What I found when things "weren't right" was a DFO problem. Something like height offset, or atmosphere

Darkker wrote:That number agrees with Shooter. What I found when things "weren't right" was a DFO problem. Something like height offset, or atmosphere

Which one mate? What is DFO stand for?

Does nobody shoot .204's long range using ballistic programs?

Anyone?

I am also waiting on DFO definition

Try this, acronyms.thefreedictionary.com/DFO . It won't answer your' question but, it might make you chuckle.

Dumb F*&#)%! Operator I believe.

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!

Does anyone know the G7 BC figure for the 39 SBK?


Steve