Twist rate help...........thanks

[Agunner012]

I was thinking about a Broughton 5C barrel for a 300 RUM. Would an 11" twist stabilize a 240 grain SMK? I know 10" twist seems to be the better choice. Then I was thinking of the possibility of playing with lighter bullets as well and that's why the 11" twist came to mind.

Thanks
Andrew

 

[bailey1474]

I don't know about the 11" twist and the 240, but I can tell you that you will have no trouble w/a 10" twist and lighter bullets.

 

[davewilson]

i'm not gonna claim to have experience here other than to report what i have heard others say. if you're gonna shoot the 240's, you'll be better off with a 10 twist.an 11 can handle the 220's but the 10 is a must for the 240.

 

[Agunner012]

Thanks for the replies, I was hoping that a high velocity cartridge like the 300 RUM could get the 240 SMK to fly stable with an 11 twist. Would one of the fast 30 wildcats in an 11 twist be able to stabilize a 240 SMK? 30-338,or 30-378? I have a 10 twist barrel on a Savage 300 win mag, it shoots the heavies OK but I am not happy with how is shoots the lighter bullets. I was looking for the 300 RUM to be able to handle the light as well as the heavies. That's why I am asking all the questions about the 11 twist, was hoping it would be a little more versatile than the 10 twist.

Thanks
Andrew

 

[davewilson]

the twist requirements of a bullet don't really change much at all with increasing speeds.you could shoot that bullet 300 fps faster and you'll still need a 10.i've heard of quite a few who shoot lighter bullets with great accuracy in a 10 twist.sounds like you've formed an opinion on this twist thing based on one gun.when you're talking cartridges in the 100 gr and up catagory,they're really not at their best using the light bullets.

 

[Agunner012]

Thanks Dave, I will have to go with a 10 twist and see what happens. Maybe its just my 300 Win Mag, or I am barking up the wrong tree. I thought I read somewhere that some bullets stabilize better when pushed faster, I was confused.

Thanks again,
Andrew

 

[Mikecr]

There is alot of shooters who think velocity is the answer to stability issues. They are wrong for the most part.
If you have a bullet on the EDGE of stable, and you push it 300fps faster, it might produce round holes(all over the place). But velocity has only a slight effect on stability. And so, you usually can't get enough from it to resolve problems.
A bigger affect is air density. If high up in Montana on a hot smmer day, you might get by with an 11 twist for a 240SmK. This is where you might get someone to say they shoot it in 11tw, and it works just fine. They might mention that they had to push it faster to get it stable. Thats because it's on the edge, even at that elevation.

Be wary of rules of thumb. Every one(that I've seen) will fail certain tests. Many are generalized definitions of what is known(hind sight). So they cannot predict what was not known at the time.
The truth passes all tests.

 

[TOM H]

To me the best source for bullet information would be Tim North (Broughton Barrels). Tim's barrels are being use by alot of the 1000yd guys now and since Tim also competes he would have alot of good information. I got one of his 1/12 5c barrels in 30 cal and want to get another one. Well good luck.