My old Lee Loader that I purchased new back in the early 60's contained instructions for producing a roll crimp. You simply worked the rammer up & down as you pushed the crimping shoulder against the end of the case, instead of pushing the crimp shoulder all the way down to start the fold crimp.
This would of course be slower than a rotary crimper, but would work if not a lot of shells were required.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra