243 AI twist rate frustration

[Prairie605]

Hey everyone, new member here. Got a question and maybe someone can give me some suggestions.

I recently aquired a rem 700 in 243 win. Serial number indicates it was built in 1974. I am wanting to re-barrel it with a Bartlein 5r in about a 2b or #3 contour barrel. My plan is to build a hunting rifle for my boys to use in a few years and for me to use on antelope and mountain lion.

I want to chamber for the 243 ackley for the added case capacity and case life benefits, and just to have something different. My frustration is I can't seem to figure out what twist to go with. One site says one thing and another says something different. I will be shooting the 85-100 grain hunting bullets like the nosler partions and hornady sst.

Most say go with the 10 twist for that bullet weight, but there lots of 8 twists available for immediate shipment. my question is will the 8 twist shoot these type of hunting bullets without any negative affects on accuracy? It seems the 8 twist is really designed for the heavy vld target loads.

 

[FearNoWind]

Most .243 bullets within that weight range do very well in barrels 1:10 or faster. But it will, of course, depend on the bullet you choose because not every manufacturer's bullets share identical base to ogive or bearing surface characteristics.
In your position, I'd opt for a 1:9 twist.

 

[B-P-UU]

For all practical purposes, you cannot 'over-stabilize' a projectile, so I would pick a 1:8 and be done with it. If you want to run the heavies later on, you'll have the pitch to do so. Like you said, 1:8's are readily available and there's a good reason why.

I see bugholes.com has both 2b and 3 Barts in stock right now. You may already know this but Bartlein barrels run heavy compared to other manufacturers. i.e., a #3 Bart is similar to others #4. I have a Bart#3 and am very happy with it.

Another good tool is Berger's bullet stability calculator:
Twist Rate Stability Calculator | Berger Bullets

 

[Hornhunter32]

I don't think you'll have any issues shooting 87-105 grain pills with an 8 twist. I wouldn't go with anything else for a 243 AI.

 

[Prairie605]

For all practical purposes, you cannot 'over-stabilize' a projectile, so I would pick a 1:8 and be done with it. If you want to run the heavies later on, you'll have the pitch to do so. Like you said, 1:8's are readily available and there's a good reason why.

I see bugholes.com has both 2b and 3 Barts in stock right now. You may already know this but Bartlein barrels run heavy compared to other manufacturers. i.e., a #3 Bart is similar to others #4. I have a Bart#3 and am very happy with it.

Another good tool is Berger's bullet stability calculator:
Twist Rate Stability Calculator | Berger Bullets

Yes sir, bug holes has them. That's where I have been looking and pondering for the last week. I was just worried about over spinning the bullets with an 8 twist.

I also have a #3 on my 300wsm and love it. I'm thinking the 2b would be a better weight barrel for what I'm wanting to build.

Thanks for the replys guys.

 

[FearNoWind]

[

For all practical purposes, you cannot 'over-stabilize' a projectile,http://www.bergerbullets.com/twist-rate-calculator/

Excellent point .................

Does Barrel Twist Rate Affect Muzzle Velocity? (Litz Test) « Daily Bulletin

 

[Prairie605]

Great info guys. Thanks for the replys. I think an 8 twist is in my future.

 

[Greyfox]

I use 1:8 in my 6mm with 85-107gr bullets in my match rifle. Results are superb.
This is a typical 5 shot group with a 105 Berger in my 6mmAR

 

[Garycrow]

Great info guys. Thanks for the replys. I think an 8 twist is in my future.

That's a good plan. There is no downside to an 8 twist in a 6mm, there's nothing to be gained by twisting it slower.

 

[the jigger]

My 243AI is a 9"twist and is not a hunting rifle. I shoot 95gr Match Kings with RL22
and 105gr Hornady Match with RL26 to within one-eighth inch of the same POI.
GOOD LUCK and GOOD SHOOTING!!!

 

[jpw360]

[


Excellent point .................

Does Barrel Twist Rate Affect Muzzle Velocity? (Litz Test) « Daily Bulletin

I remember Tiborosauruse disagree on that one....cant find the link but will try

 

[Prairie605]

Got an 8 twist #2b Bartlein in the mail. Can't wait to get it put on and start working up a load for it.