If it were me, to save a bit of shipping costs, I'd buy a 20, 21, & 23#
The Delta Elite runs a 23#, the bull barrel is not going to slow
the slide much.
If you had a squared firing pin stop you could
lower the spring pressure a few pounds. However the squared
fps placed a bit more wear on the hammer & pin. I prefer to
tune with springs for the load at hand.