12" barrel twist

[Methow Packer]

I had a gun smith rebarrel my 300WM rifle. We installed a Brux fluted stainless 26" #4 contour. Great job of installation . Shoots half MOA if I do my part. I realized later he used a 12 " twist barrel recommened by others as the ideal twist. He must have felt it was what I needed for 185 grain bullets etc. I had wanted to explore the option of 210 Gr VLD for better BC at longer ranges up to 1000 yards, but I 've learned that a 12" twist is not the best twist for that bullet. Can some one shed some light on this and possibly tell me if that bullet could work down range with this twist. I'll try it anyway to find out for myself. Thanks in advance.

Ted

 

[FearNoWind]

I just did some quickie calcs and, close as I can come using that quickie approach, is that you'd need somewhere around 4500 fps to stabilize the 210 grain Berger VLD in a 1:12 twist. IMO, you can't get there from here.

 

[BryanLitz]

I agree, the 1:12" isn't really fast enough to get all the BC out of the 210. You might get it to shoot good groups, but the BC will be somewhat below it's potential at that stability level.

Unless,

You're shooting at 3000-4000 feet above sea level. At that altitude, the stability will be high enough from the 1:12" twist that it will be good. But if you're closer to sea level it will be iffy.

Take care,
-Bryan

 

[FearNoWind]

Sorry ..... no post here. I posted to another thread and it ended up here. Go figure .....

 

[Methow Packer]

Thanks for the responses. I knew the answer but thought there might be some hope. I'll stay with 185 VLD and according to Berger's twist chart maybe even work with 175VLD. Or I could start over with a 10" twist. I'd look for a different smith at that point. Partly my fault for not making sure of the scope of the work

 

[Michael Eichele]

Most 200 grain pills will work in a 12x just fine unless you're low altitude and cold air. Not sure about the 200 hybrid but it would be worth a try. I've used the 208 in 12x barrels at 308 velocities and at 2000' in 15 degree air they were key holing slightly at 700 yards. In warmer air I think they would have worked fine.

 

[Methow Packer]

Most 200 grain pills will work in a 12x just fine unless you're low altitude and cold air. Not sure about the 200 hybrid but it would be worth a try. I've used the 208 in 12x barrels at 308 velocities and at 2000' in 15 degree air they were key holing slightly at 700 yards. In warmer air I think they would have worked fine.

What you are saying is encouraging. Thanks to you and Bryan Litz. I live in north central Washington. Right now it's -7 deg so I'll wait till it warms up some and try some long range shooting at @ 3000 feet. This time of year up here it can be hard to find a suitable area to shoot. mostly access considering the weather. I've got a box of 210 VLD hunting bullets to work with and some H1000 and Retumbo powder.