From Savage Arms:

Some time ago, Savage announced it would be chambering the Model 10 Precision Carbine in 300 AAC Blackout. Since that time, we have tested many variants of this cartridge in various barrel lengths and rates of twist. This exhaustive testing left us quite unsatisfied with the accuracy we were able to get from the subsonic loads in this chambering. Accuracy with the lighter, faster loads in this caliber was actually quite good. But we believe the real value in this cartridge lies in the use of subsonic loads for suppressed rifles. Therefore we have decided to scrap the project.

It is our understanding that pushing these heavy, slow bullets presents challenges not found in typical loadings and that our experience is not unique. Subsequently, many in the industry have simply adopted a lower standard for accuracy for these subsonic loads. While this does seem reasonable and we don’t criticize any in our industry that have taken this approach, it just won’t work for Savage.

Our brand was built on accuracy and we are too protective of our reputation for building the most accurate factory rifles available. We would rather walk away from this opportunity than sell a product that requires an explanation.