7mm barrel with tight twist 1:7.5

[Burr]

Yeah, I should probably call and try asking barrel makers this question first - but I thought I would ask the forum if anyone is aware of a barrel maker that makes a .284 barrel with a 1:7.5 or faster twist?

My situation - I've got 2 Savage 110's in 300 Win Mag with shot out barrels. Throat erosion occurred before I bought the guns - so they were purchased as project guns from the get go. I don't have much into them - $350 total for both guns, knowing they need barrel replacement.

Choices are slim if i stick with the .532 bolt face - and the new 197 gr 7mm Sierra bullet with a .780 G1 BC has got me thinking. Maybe another 7mm Mag which would also allow me to use existing .532 bolt face, and I'm already spooled up with brass, dies, bullets, etc to load for it. I've got 2 7 Mag's now - but neither will stabilize the new Sierra bullet.

Does anyone make a barrel with a fast enough twist - or is it going to be an expensive custom order for me?

I'll barrel one back to 300 Win Mag - and if I can find the right twist in .284 I may have a plan for the other one.

[Rob01]

Bartlein can do non standard twists but they offer an 8 twist in 7mm. I know Sierra says 7.5 but sometimes especially with a magnum you can get velocity to get you stable where a slower cartridge might not. Maybe pop the data in the Berger twist calculator and see.

For that 300WM you should look at a 9 twist and check out the Hornady 225 ELD-M bullet with a .777 BC.

[cowtownup]

I don't think you will need that tight of a twist to stabilize the 197 SMK. I bet you can get it done with a 8.5 or even possibly a 9 twist. You can always shoot the 183 SMK if it doesn't work...

[gbflyer]

PacNor shows a 5 groove 7 twist.

[Burr]

Thanks for pointing me in the right direction. I've got some reading to do.

[RC20]

Shilen lists two types groves in 1-8 twist and a note that its 180 gr bullets.

http://www.shilen.com/wp/shilen-products/shilen-barrels/calibers-and-twists/

Jim at NSS is great to deal with for ordering (he reps Shilen and Criterions)

[simo hayha]

well,,,the new "bee's knees" round is 7-300wm so maybes keep the 300 boltface



1/8 twist will be plenty for the new heavy 7s, good luck/shootin

[J.Baker]

Thee was a similar question asked in the comments for the press release on the 197gr SMK I published a few weeks ago, so I emailed Rich Machholtz at Sierra about them and here is his reply:


Broughton Rifle Barrels is ready to do 7mm-7.5 twists (920-922-4882). This bullet is so new we don't have any input from shooters yet but I'm guessing that a 1-8 will work, at least in the warm summer and high altitude. The 8.5 will be very marginal.

This big bullet will require some horsepower and I doubt if the 7mm-08 is big enough. I'd say the 284 will require a long action/mag box to get any velocity by getting the bullet out of the powder space. Even then I'm guessing 2700 fps will be about max velocity.

As we get more shooter input we'll know a lot more. Stay in touch and I'll try to keep you up to date.


I'm thinking someone needs to do up a 7mm-338 Lapua for this bullet. Where's Scope Eye? That would be right up his alley.

[RC20]

That would be quite the rig.

Someone has to be thinking of doing it with the new non belted cases to use.

338 Lapua 06, 7mm, 270! Lot more.