Berger 205 for Tikka .3006

[nuvreaujason]

Hi everyone,
Merry Christmas and a Happy New Year to all!
I have a quick question. I just got some bullet replacements from Berger, but instead of the 180 grain elite hunters, I got the 205g elite hunters. My question is in regards to barrel twist. My barrel twist is a 1:11. With the 180s I was getting .88 MOA under 54 grains of imr4451. The reason I wanted to try out Berger was due to their secant design and I wanted something heavier for longer ranges. The SMK 168s were giving me great accuracy (.22 moa), but I would have a harder time reaching out past 600 yds. Do you think that these 205g will give me any trouble in regards to stabilization? They recommend a minimum 1:11. If you think they would give me trouble, do you think there is someone that could trade my 2 boxes for some 180 elite hunters?

 

[Ned Ludd]

At a velocity of 2550 fps and modestly conservative elevation/temperature values (500 ft/65 degrees F), the Berger twist rate calculator predicts a gyroscopic stability coefficient (Sg) of 1.40 for an 11-twist barrel, which is plenty with regard to stability. If your velocity, elevation, or temperature is lower, the value will be reduced accordingly. However, unless the Sg gets down in the 1.1 to 1.2 range or lower, it shouldn't be a problem in terms of bullet gyroscopic stability. In other words, you wouldn't expect oblong holes in a target face or keyholing, or anything that extreme. Running a slightly slower than optimal twist rate usually means the bullet will behave as if it has a slightly lower BC value than it actually does. As long as it's not much too slow a twist rate (i.e. a predicted Sg below 1.1 to 1.2), there should not be a noticeable effect on precision.

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

 

[nuvreaujason]

At a velocity of 2550 fps and modestly conservative elevation/temperature values (500 ft/65 degrees F), the Berger twist rate calculator predicts a gyroscopic stability coefficient (Sg) of 1.40 for an 11-twist barrel, which is plenty with regard to stability. If your velocity, elevation, or temperature is lower, the value will be reduced accordingly. However, unless the Sg gets down in the 1.1 to 1.2 range or lower, it shouldn't be a problem in terms of bullet gyroscopic stability. In other words, you wouldn't expect oblong holes in a target face or keyholing, or anything that extreme. Running a slightly slower than optimal twist rate usually means the bullet will behave as if it has a slightly lower BC value than it actually does. As long as it's not much too slow a twist rate (i.e. a predicted Sg below 1.1 to 1.2), there should not be a noticeable effect on precision.

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

Thank you Ned!