The only reason I suggested the bullet lube you said the dies were adjusted properly. If so and the cases have all been trimmed properly too the same length, if not some will be over crimped. If say the die was set with a short case.
I have seen small differences in
C O A L with dies that have a build up of lube, I believe the bullet dose not start squarely in the seater plug, and this leads to bullet run out.
This being a Handi rifle, single shot I too would not crimp the bullets,
Just me but the only rifle rounds I crimp are hunting rifle rounds in box or tube Magazines. Or Semi autos, And then only with cannelure bullets. Others do put a light crimp on non – cannelure bullets, but it is very easy too over crimp them.