looks like no 1:7 for a .243. I did find this chart but I don't know how complete it is.
Rifle Barrel Specifications:
Bore Groove Diameter - .243".
Common Barrel Lengths - 20" to 26".
Common Barrel Twist Rate - 1 in 10" & 1 in 9" (uncommon) 1 in 12" & 1 in 8".
1 in 9" twist rate: Remington 660, 700 & 788 (old).
1 in 9.125" twist rate: Remington 700, 7400, 7600 & 7.
1 in 9.250" twist rate: Savage (current production models).
1 in 10" twist rate: Browning.1 in 10" twist rate: FN.
1 in 10" twist rate: H and R models 300, 308 & 360.
1 in 10" twist rate: Husqvarna.
1 in 10" twist rate: J.C. Higgins 51-L.
1 in 10" twist rate: Mannlicher Schoenauer.
1 in 10" twist rate: Mossberg 800.
1 in 10" twist rate: Musketeer.
1 in 10" twist rate: Remington 700, 40-XB.
1 in 10" twist rate: Ruger 1 & 77.
1 in 10" twist rate: Sako Bolt & Lever Actions.
1 in 10" twist rate: Savage 99, 110, 111, 112-V & 116 (old).
1 in 10" twist rate: Schultz and Larsen.
1 in 10" twist rate: Stevens 110.
1 in 10" twist rate: Thompson/Center Rifles.
1 in 10" twist rate: Weatherby Vanguard.
1 in 10" twist rate: Winchester 70, 88, 100, 670 & 770.
1 in 12" twist rate: Steyr SSG-PII.