I'm confused (very easily done). If "pressure is pressure" and there is no difference then why not shoot smokless low pressure loads and not have the other cleaning issues (and others) that come with BP? I've got a Winchester 1893 12b that I am planning to shoot BP through. Could I shoot low pressure smokless through it as well? I was sticking with BP, due to the gun being made/designed for BP. This model has also had a history of not being able to hold up to the switch to smokless powder. Hence the introduction of the new and improved Winchester 1897. I guess I was under the assumption that BP always produced lower pressures.
