Since the pins serve to position the FSB and prevent it from shifting, the pins are in TIGHT, TIGHT, TIGHT.
What you have to do is get the FSB and barrel well braced in a no-move, no-bounce setup.
If when you hit a pin the barrel moves or bounces AT ALL, the force of the blow is dissipated, and not only will the pin not move, it will often deform, locking it even tighter in place.
Next, make up a "starter punch" from a standard pin punch by cutting it off to about 1/2" inch working length.
Full length punches tend to bend and flex, again, dissipating the force.
The short starter punch is much more rigid and will direct full force to the pin.
Once the pins are started out, switch to a full length punch.
