Please help me understand why?

[snox801]

So I've had two semi custom rifles built with different smiths. Both where told that unwound only be shooting the heaviest bullets for caliber. So got my 257 Roy back with a 1/10 twist seems to do the job with 115 noslers. But looking at Berger its marginal for stability. Second I had a 6x45 built on a Howa action. Thought I would leave it to the smith to make the correct call. I stated I would only be shooting 95gr bullets. Nothing lower. Also got this back with a 1/10 twist. Looks like I should have gone with maybe a 1/8. Shooting just over moa with some load work. I'm sure I can get it dialed in but can't figure why they would use this twist rate. Is bergers calculator really airing on the side of caution. Or should I just start requesting the twist rate I feel would be best.
Thanks in advance

 

[Edd]

If I wanted a specific twist rate, I would ask for it.

 

[MagnumManiac]

First off, a 1:10" twist in 257 Roy is plenty, you must remember that the faster a bullet is pushed the easier it is to stabilise.
Secondly, Berger has some very long 115gr bullets which may not, doubtful, stabilise in a 1:10" twist in slower calibres. I run a 257AI and a 25-06, both with 1:10" twists, no problems with ANY conventional bullets, but got poor accuracy with 115gr TSX's in both rifles, probably not due to twist rate, just crappy bullets.
Your 6x45 should be OK with the 1:10" twist, I don't see it being a problem.

Cheers.
gun)

 

[KYpatriot]

You should always listen to a smith and consider his expertise, but it's your call, they can't know everything about everything.

 

[shortgrass]

I've been thinking about a .257 A.I. , but thought I'd go with a 9 twist. I'd not be concerned about going down to 85g. bullets at all and it'd handle most all 115g. I'm currently shooting a 6mm x 45 with a 1-12 twist and 85g Sierra Blitz. The 6 x 45 is extreamly sensitive to primer manufactuer. Seat anything but a Win. SR behind a charge of 748 and it goes wild. Using the WSR it's darned accurate. Maybe I just got lucky with the 6 x 45 as the first load I tried (748 ahead of the WSR & using the 85g Blitz) is the one I still use. It took virtually no "load developement", just worked up to max (by chronographed velocity).

 

[HARPERC]

If I wanted a specific twist rate, I would ask for it.

Absolutely! Even to the point of writing it all down prior to starting.

 

[FEENIX]

If I wanted a specific twist rate, I would ask for it.

Ditto!

 

[Dosh]

801, my .257 Wby is sub 1/2 MOA at 200 with 1 - 10 and 115 Bergers. Ditto goes for a couple of my friends .257 Wby with same bullet. As for the 6X45, can't help with that, but I'm sure someone here can.

 

[snox801]

Hey thanks guys guess I'm OK then. Like I said iI'm getting good accuracy just second guessing my self with the 6x45. Also thanks for the heads up on primers I'll try that next and see what happens.

 

[J E Custom]

You should always listen to a smith and consider his expertise, but it's your call, they can't know everything about everything.

Good advice. But ultimately the choice is up to you. Your smith should explain why he recommends
a certain twist so that at least you are aware of the potential problems with your choice.

Some think a fast twist will shoot everything well. (Not So). If you build for one bullet you may find that the bullet will not shoot, then you are up the preverbal creek.

Most Smiths will elect to use a twist that will shoot everything (All bullet weights) so the owner is
not limited to what he can shoot "OR" what the rifle/barrel likes Based on there experience
and comments from his rifle owners.

If a smith flat refuses to build it the way you want it,he has a reason. It can be the accuracy guarantee. (He ether knows it wont work, or can be dangerous) or is trying to get out of his guarantee. If it is the latter, RUN.

He may not know everything, but he should have a feel for what works best and be able to explain the reason for his recommendation.

Some bullet makers will make a recommendation based on there bullet only with no consideration for other brands and weights of bullets.

The barrel makers can help make recommendations for the best twist and number/style of grooves.

Hear is an example= Lilja Precision Rifle Barrels - Caliber and Twist Rates

J E CUSTOM

 

[KennyA12]

Had 223 rebarreled,called beforehand about what I wanted. Sent rifle with detailed instruction for twist and weight of bullet, would not shoot. Called the smith and he said I should have told him in the beginning. Sent him a copy of my original letter, he replaced the barrel with no more said.

 

[FEENIX]

Good advice. But ultimately the choice is up to you. Your smith should explain why he recommends
a certain twist so that at least you are aware of the potential problems with your choice.

Some think a fast twist will shoot everything well. (Not So). If you build for one bullet you may find that the bullet will not shoot, then you are up the preverbal creek.

Most Smiths will elect to use a twist that will shoot everything (All bullet weights) so the owner is
not limited to what he can shoot "OR" what the rifle/barrel likes Based on there experience
and comments from his rifle owners.

If a smith flat refuses to build it the way you want it,he has a reason. It can be the accuracy guarantee. (He ether knows it wont work, or can be dangerous) or is trying to get out of his guarantee. If it is the latter, RUN.

He may not know everything, but he should have a feel for what works best and be able to explain the reason for his recommendation.

Some bullet makers will make a recommendation based on there bullet only with no consideration for other brands and weights of bullets.

The barrel makers can help make recommendations for the best twist and number/style of grooves.

Hear is an example= Lilja Precision Rifle Barrels - Caliber and Twist Rates

J E CUSTOM

Ditto! When I was gathering information on building my .270 AI, my smith recommended 1st recommended 1:10" twist but after informing him that it would primarily be used for the 165/175 Matrix and after consulting with Dan Lilja, he supported my goal and went with a Lilja 1:8 as that is the recommended twist by Marshal of Matrix to stabilize the 165/175 bullets.

As it turns out, according to Bryan Litz' latest BC calculations for the Nosler LRAB, it will also stabilize the 150 LRABs.

Cheers!