I admit to a bit of confusion regarding twist rates. For instance, if a 1:70 is good for a roundball, why isn't a 1:48 even better? If a 1:24 is good for a sabot, why not a 1:12 even better? Clearly, there may be a point at which you simply can not get an object to rotate in such a short span under the desired powder charge. Maybe that barrier is the 1:21 found in carbines. Apparently so, for sabots. Maybe the 1:21 is optimal for sabots, a 1:28 for conicals and 1:70 for PRB. I suspect as much. Just wondering why there isn't a pretty darn accurate table where you could look up virtually any bullet on the market, match it up with a given powder/charge, and get the optimal twist rate for delivering it accurately.