Swift and 90gr Berger...

[ISS]

Do you think I can get the 90gr Berger to stabilize at 3100fps with an 8" twist? I see a 7" twist as too hard for LR accuracy with a 75-80gr selection; but I hate to get an 8" twist and waste 300 of the 90gr bullets.

thanks,

Rich

 

[17VLD]

I don't have any concrete evidence but I bet at your altitude it would. I think I'd get the 8 and try if not you still have a lot of decent choices that will work with the 8. The new 69 BlitzKing sounds like fun on Idaho rockchucks with your Swift as well as all the heavier offerings from Hornady.
Matt

 

[newbieshooter]

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

 

[SeabeeKen]

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

I've had bullets stabilize when that calculator said they wouldn't. I take these things with a grain of salt and test for myself to see

 

[charlie b]

When you are on the edge of stability little things can mess it up. I could shoot 75ELD's with a 9 twist on hot summer days at 4500ft elevation. But, during the winter they would not.

 

[Gary in MD]

Personally, for a hunting rifle, I’d take the 8 twist and be able to shoot everything from the 55 grains to around 80 grains or so.

 

[ISS]

I know the 8" twist is dancing on the edge of stability. I just do not want to restrict my bullet choices.

thanks gentlemen,

Rich

 

[longridgehunter]

Don't sleep on the 85.5 berger for your 8tw

 

[RabbitSlayer]

Split the difference and get 7.5? If that is the bullet you are looking at I dont think you would be worried about shooting 55s and such...

 

[ELR LVR]

Do you think I can get the 90gr Berger to stabilize at 3100fps with an 8" twist? I see a 7" twist as too hard for LR accuracy with a 75-80gr selection; but I hate to get an 8" twist and waste 300 of the 90gr bullets.

thanks,

Rich

if you do get an 8 twist
you still have 69's, 75's, 80's, 85.5's to choose from and use
why would you want to be held fast to a qty. of 300 - 90 grainers?
the BC difference is negligible from a 500 pack of 85.5's

 

[charlie b]

You're real choice is in the throat length and how deep you want to seat the bullets.

 

[barefooter56]

Do you think I can get the 90gr Berger to stabilize at 3100fps with an 8" twist? I see a 7" twist as too hard for LR accuracy with a 75-80gr selection; but I hate to get an 8" twist and waste 300 of the 90gr bullets.

thanks,

Rich

Optimal barrel twist rate for the 90 VLD IS 1-6. For the 85.5 is 1-7 to 1-7.5 based on 59 degrees at sea level. One of the posters is correct with his ALTITUDE comment as altitude is the biggest factor there is in determining barrel twist rate you will need. Us our website TWIST RATE CALCULATOR to help you with this:

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

Hope this helps.