You don't set bullet resistance with crimp, neck/case tension decides that.
A taper crimp just needs to remove the bell you put in with your expander die and a slight amount more so it will feed reliably, depending on the firearm. As you found, no amount of extra crimping will make the bullet tighter in the case.

Since lead is normally larger diameter than a fmj and they aren't making it through your gauge, I'd say you need to shorten them up until they make it through.
Since you are going to be shorter, working up from a minimum load is a given.
Which leads to:
Seating depth(Amount of projectile contacting surface inside the case.) might have something to do with the problem of them moving easily. Being lead is likely to be denser than the fmj and if you are seating to the same O.A.L. there will be less bullet inside the case. Shorter O.A.L. will probably solve that issue also.