you will need to call Browning.Browning chose a 1"in 14"twist rate for all rifles chambered in 22-250 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.
It should be stamped on the barrel
Try the Browning customer service dept at link below
Rate of twist on this model is 1 in 9 1/2"
Impossible to answer without knowing the caliber.
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.
It may be different depending on the year and the caliber, but recent catalogs show that the few A-Bolts witha 24" barrel have a rate of twist at 1-10"
Browning,s home page should contain this info.
You will need to call Browning.
According to Linda in the customer service department at Browning Winchester at (800) 945-5237 the 12 Ga models have a 1 in 28 twist rate.
You will need to call Browning or take it to a gunsmith.