I\”ve loaded em with 24.6gr of TAC, CCI450 primer, seated at 2.250\”. They worked pretty decent in my 16\” carbine at 2740fps
I\’ve also loaded em a tad hotter with 25.7gr of W748, CCI450, also seated at 2.250\”, same carbine at 2745fps
I\’ve recently backed that last load down to 25.6gr of W748 due to a different LOT# on that powder, but still with decent results, 2700fps
As always, use of any internet load data is strictly at your own risk. For a 20\” gun like yours, I\’d definitely suggest starting with lower charge than those mentioned and work up your ladder to find a nice node for your particular gun.