Miller Stability Formula Question

[jrsolocam]

I have a Sako TGRS in .300 Win and it has an 11" twist. I want to try the Berger 230 Hybrid, but a 10" is recommended. I am hoping not to rebarrel now. When I run it through the Miller formula (@ 2750 fps) I get a 1.31 SG. 1.4 and above is considered very stable, while less is considered marginal.

My question is this: When a bullet is not quite stable like this, where does it usually show up? Right away, or downrange somewhere? I'm not looking at shooting to transonic, maybe 6-700 yards.

Thanks for your input!

 

[CliffM]

I shot the 215's this morning from an 11.25 twist 30-338 at 2880fps and they were stable to 1030yds. They are suppose to require a 10 twist also. They measured only .020 shorter than the 230's are listed at. I don't know how much difference that actually makes.
I have had badly unstable bullets keyhole at 100. Marginally stable bullets may fall apart a long ways out, dropping a shot low every now and then.
Cliff

 

[elkaholic]

I have a Sako TGRS in .300 Win and it has an 11" twist. I want to try the Berger 230 Hybrid, but a 10" is recommended. I am hoping not to rebarrel now. When I run it through the Miller formula (@ 2750 fps) I get a 1.31 SG. 1.4 and above is considered very stable, while less is considered marginal.

My question is this: When a bullet is not quite stable like this, where does it usually show up? Right away, or downrange somewhere? I'm not looking at shooting to transonic, maybe 6-700 yards.

Thanks for your input!

I'm thinking you should be ok, especially at the ranges you are talking about......Rich