The "rate of twist on rifling" is caliber specific. To give you an answer we would need to know which cartridge the rifle is chambered for.
The Springfield 1903 has a 1" in 10" twist rate. The later M1 service rifle also has a 1" in 10" twist rate.
You will need to call Browning.
The rate of twist for a Browning X-Bolt 24-inch barrel typically varies depending on the specific caliber of the rifle. For example, the .308 Winchester generally has a twist rate of 1:10 inches, while the .30-06 Springfield may also feature a 1:10 twist. Always refer to the manufacturer's specifications for the exact twist rate corresponding to your specific X-Bolt model and caliber.
You will need to call Browning or take it to a gunsmith.
Depends on the caliber.
The Browning 2007 Product Catalog states that the A-Boltchambered for 25WSSM with a 22" barrel has a 1 in 10" rate of twist.
Rate of twist on this model is 1 in 9 1/2"
Try the Browning customer service dept at link below
1 in 9
It will vary with caliber.
1:16