243 AI With 8 twist light bullets

[farmer44]

I'm thinking of building a 243 AI. I have a 8 twist barrel heavy varmint laying around with a brake. I want to shoot the lightest bullet possible 55 and 60 grain also recommended free bore that would work with heavier bullets if I change mind on weights. Cant seem to find much info on the Ackley with these light bullets. Hoping for 4000+ fps. Any input appreciated. thanks for looking.

 

[nmkid]

I'm kinda sure you will need a slower twist than that. My factory .243 would not shoot the 55 gr bullets very accurately but, it did OK with 58 gr. bullets

 

[farmer44]

Well that is disappointing. I have this barrel here and trying to put it to good use with light bullets, maybe a 6x47 Lapua or would anyone have any other ideas.

 

[farmer44]

how about 60 or 70 grain.

 

[Mark W]

Being a 1:8 twist I would at least throat it for 85 to 90 grain bullets. You could still try jumping the lighter bullets and see how they do.

 

[ballisticxlr]

I've run 55gn bullets from my 8-twist .243AI in excess of 3900fps from my 26" barrel. If you want 4000fps, it's possible but I'd go to a 28" barrel so you don't have to push it so hard. The load to get there for me was about 45 grains of BL-C(2) which is a TON of powder behind that little pill. It needed either CCI magnum primers or Winchester primers to keep SD's down.

 

[farmer44]

THATS VERY HELPFUL I am going to try to throat it for some 70 gr BTHP I have 600 or so of them. But I am all ears if anyone has more input and thanks much everyone.

 

[MrMajestic]

Varget will get you some pretty impressive velocities and accuracy in that bullet weight range. I got 3850 with the 70 BK's in a 14tw.

 

[Zero333]

Some lighter bullets like the vmax will be ok in a fast twist cause they have tougher jackets.

I shoot 80 he Berger Varmint FB in a 8" twist... But ONLY in freezing temps because when the barrel warms up, some 25% of the bullets never make it to the target. I've slowed them down 300 fps and they stay together, but groups grow 25% bigger.

 

[NZ_Fclass]

I agree with Zero333. God knows how many bullets I have blown up in a 10" twist 243 AI. I now stick with 85/87g. and ADI 2213 ( H1000 to you) Rabbits and goats still die quickly.

 

[farmer44]

with the 70gr Sierra can anyone provide some load data by chance

 

[10XSHOOTER]

I have a .243 with 30* shoulder. 8 Twist. I'm shooting 95 gr tipped match kings for Coyotes. Getting over 3600 moly and RL-19

 

[farmer44]

I took the barrel to gun smith had him throat it for 70gr Sierra's should have it in about 2 weeks I will experiment with it for a bit.

 

[Mark W]

I took the barrel to gun smith had him throat it for 70gr Sierra's should have it in about 2 weeks I will experiment with it for a bit.

Don’t forget to post up some results when you get it running.

 

[farmer44]

Will do