It seems to me you can do it,but listen to Joe -he knows stuff,{[the drum normally would be removed }and a “liner”of sorts installed with a hole leading to the powder chamber in the breech,then a flint lock would be inletted and installed -aCVA flint lock would be easiest,but I thought they were small for a rifle,but mine worked fine and good luck on finding one maybe.NOTE,I said the drum would be removed and Joe said if you remove the drum difficulties reusing it are indicated! If he said that there is a reason it may be a one way job,once a flint always a flint ,he probably knows more than I do about this ,I think ,if a drum is loosened It is like any threaded bolt type item stretched and will not fasten down in the same exact spot and may need to be tightened more to be secure,this means the nipple will be further clockwise then before and out of line with the hammer -kind of important.-I have not ever done this I only THINK I know what to do and might be overlooking something else also! It’s easy to be a capper…it’s easy to be a flinter but hard to be both.I have heard of “switchers” but never made much sense to me. Have more fun ,buy a flintlock too.