Berger 6mm 69 gr High BC FB Length?

[RonAKA]

I'm trying to determine the spin rate needed for this bullet. I know Berger says 12, but I wanted to try the Don Miller formula to see what it says. Would anyone be able to give me the accurate length? Or, better still is there any on line information which gives these bullet lengths?

Any help you can give is much appreciated,

Ron

 

[zedsdead]

Ron

I have two 223s and have never gotten any 69gr bullet to stabilize in 1-12 twist barrels, no matter how fast I push them. I believe you're going to need a 1-9 twist.

 

[RonAKA]

But this is a .243" size bullet...

 

[RonAKA]

Thanks Gunamonth for taking the time to do that. I ran that bullet size through the Don Miller formula and came up with a minimum twist of 10.4 to get a 1.4 stability at 3100 fps. I wonder what gives Berger the confidence to say a 1:12 is enough?

Ron

 

[steveyrock]

I am shooting that exact bullet in a twelve twist Hart.Five shot group at 100 yds during load development.

 

[EricStecker]

RonAKA,

To determine the twist needed we run our bullet dimensions through a program designed by renown ballistician Bill Davis,inventor of the VLD design). Our confidence in Bill's program is primarily due to many years of being proven correct,as steveyrock points out).

I have not heard of the Don Miller system. A 10.4" twist will stabilize our 6mm 69 gr but it is a faster twist than you need.

Regards,
Eric

 

[RonAKA]

Eric, thanks for the clarification.

Ron

 

[trgtsnpr]

the 69 gr berger bullets are suppose to be .923" oal if your looking for bullet info go to midway find the bullet you need info on then click on specification and use and that will give you all the info you need hope that helps