7mm 9 1/4 twist with 175gr & 180gr SMKs Question

[UNCIVILIZED]

Gents, I'm on a bit of an info hunt. What I'm wondering is, will 175gr & 180gr SMKs properly stabilize when fired out of a 9 1/4 twist barrel in magnum calibers. Meaning 7mm RM, 7mm WSM etc. Sierra's website strongly suggests a faster twist. But I know that plenty of guys have fired bullets north of 200gr in 11.25 & 12 twist .308s with great success. Thus my question
I'd surely love to be able to use the high BC's of the heavier slugs, but if they wont stabilize...

Thanks

 

[turbo54]

IIRC, the 175smk measures 1.445" long.

Even if it were 1.500" long, a 9.25 twist provides a stability factor of 1.45 with a MV of 3000fps at 59ºF and 29.92 inHg Baro.

Technically speaking, a stability factor of 1 or more should do it, but experts tell us you should go for 1.4 or greater to ensure good stability.

I think you'd be good to go.

 

[UNCIVILIZED]

Thanks, I'd run the numbers. Was just wondering if anyone had tried it. Seems like Sierra is pretty conservative on all of their twist numbers when compared to some other bullet makers. Though I can honestly say I was a bit astounded several years back when guys were throwing 210gr slugs out of short .308s, & getting great accuracy.

 

[260shooter]

I shoot 175's out of a 9 twist with no issues to 1K.

 

[mwroseberry]

I ran into issues pushing the 180s out of my 9.25 twist at 2900fps. I have since switched to the 162 and pushing them at 2965 with no stability issues and very good accuracy before the barrel starts to heat up using H1000.

Good luck,
Merritt

 

[aidenpeacemaker]

smk

I prefer the 180s

 

[Jerry m]

I shoot 175 SMK out of a 9 1/4 twist 7mm Rem mag with excellent results.

Good luck

Jerry

 

[flounderv2]

I shoot a SAC Built .284 Win with the following specs:

27" 9t Bartein Barrel
4831SC
Chronod a bunch of rounds this past weekend
Temp 40F
DA - 593

162 Amax @ 3100 fps
175 SMK @ 2900 fps
180 Berger VLD @ 2850 fps

I shoot the 175 SMK with no problem to 1 mile.