300 Weatherby 125 nbt questions

[Camaro80z]

I'm shooting 125 nosler ballistic tips in a 300 weatherby. 28" 10 twist barrel, weatherby brass, 210m primers, stiff charge of h4350. It is a short throated chamber .060 freebore. Bullets are jumping .010. Magnetospeed v3 is giving me velocities right at 4,000fps. My problem is I can not for the life of me get my drop info in my shooter app to reflect the drop I'm experiencing in the field. I have all my info plugged in perfectly. The only way I can get the drops to match up is drastically raise the bc of the bullet or drastically raise the speed. Does the higher than average speed raise the bc? I know the bullets are also overstabilized, would that effect bc also? At 670yds shooter calls for 8.9 moa of elevation. I shot way high. Worked the scope down until I hit which ended up being 4.5 moa. Ran scope back down to zero then back to 4.5 and hit again. Grabbed my 6x284 plugged in the info for 670yds for it with no problems and made a first round hit. I'm pulling my hair out here. Any help would be greatly appreciated.

 

[joshb]

Maybe the bullet is picking up speed after it leaves the barrel?



Sorry. I couldn't resist.
Do you have your elevation, humidity, temp, I.e. "Air density" plugged in correctly?

 

[Camaro80z]

Yes sir, I collected all the atmospheric data when the load was initially worked up and saved it. Then every time and every place I shoot I pull the real time conditions and use them as well.

 

[4xforfun]

I ran into the same problem before. Eventually I found a decimal point in the wrong place somewhere along the line. Pissed me off somthin awful!!! I SWORE I had the inputs correct.

Good luck,
Tod

 

[Camaro80z]

I'm going to go through everything again right now. Thanks for the reply

 

[long40shot]

Do you hunt with this combination?

 

[Camaro80z]

It's just for shooting groundhogs

 

[4xforfun]

It's just for shooting groundhogs

a 125 nbt @ 4000. That otta gitter done!!!

 

[Camaro80z]

Yea the couple I shot last weekend at 200yds and less became part of the atmosphere.

 

[KenOath]

Are you allowing for the angle to target? If your shooting up or down hill/valley/cliff etc... the moa needed to get to target is less if shooting up or down hill, the steeper the angle the less moa I believe. Just a thought??

Cheers Rushty

 

[4xforfun]

Are you allowing for the angle to target? If your shooting up or down hill/valley/cliff etc... the moa needed to get to target is less if shooting up or down hill, the steeper the angle the less moa I believe. Just a thought??

Cheers Rushty

He is off by as much as 50%. Think about the kinds of elevation differences it would take to cause a 50% change.

 

[Camaro80z]

I was only shooting at a -1 or -2 angle. Programming that little bit in made no difference. I shot the rifle over the weekend again. All data input is 100% correct. Ended up adjusting the bc to .405 and all was well. Shot the rifle to 800yds with no problems. Seems the high speed and 3.17 stability factor raise the bc for at least a certain distance of the flight. That's all I can come up with.

 

[MrMajestic]

Is the S/W grabbing the correct form factor, G1 or G7? I've experienced your conundrum before and always adjust the BC to correct as I know the velocity.

 

[Camaro80z]

The shooter app was pulling the Bryan litz profile for the bullet using the G1

 

[rardoin]

Check your 'scope zero distance' and make sure it is set for your actual zero. I recently had the same issue and somewhere I had set the scope zero for 300yds when I always zero for 100 in that rifle.

 

[Camaro80z]

Got the zero distance entered in correctly. Like I said the only thing that made things line up was to raise the bc.