Using snubber diodes for DC motor and relay
The "right" diode to use in this application is the Schottky diode.
It is a much faster diode than the others.   Zeners are NOT the appropriate choice.   

Imagine there is a capacitor across the diode (in parallel).   This capacitor has to be charged before the diode can begin conducting.  If the capacitor is bigger, it takes longer to start conducting, and that allows the voltage spike to rise higher before it's snubbed.

All diodes have this capacitor inside them.   It's called "Junction capacitance".   Schottky diodes have a much smaller capacitor than silicon diodes (i.e. 1N4148, 1N4001).   That means they'll switch 'on' faster - much faster.    

1N4001 is a very slow diode - It's a power diode meant to work on low-frequency power applications like 120/230VAC rectification (i.e. 50 or 60 hz).  That's thousands, maybe millions of times slower than an inductive voltage spike from a relay, so it's perfectly suitable in that application.

The 1N4148 is a 'small signal' diode - meant for switching very very light and lower power signals.  It is tiny and not suited for snubbing those high-voltage spikes w/o failing. 

At my company, we use 1N5819 diodes by the millions on small DC motors for this same purpose.    Note the diode you have, I found a datasheet and it doesn't list the junction capacitance, but it IS a high-power diode.   High power likely equals big junction which means big capacitance.   In other words, of the three diodes you have on-hand, it's the best choice.  But it may not be a good choice...   You might want to seek out a much faster diode (1N5819 is probably too small for your application - look for a bigger device with very low or zero 'reverse recovery' - That's a measure of switching speed ).   

There are other options.  For example, you could use a transistor to switch the actuator SLOWLY.  Transistors aren't just on/off.  If you use a MOSFET, and put a small RC network on the gate, the rate of change from ON to OFF will slow down, which will limit the rate of change of current through your actuator.   Per Faradays law, the induced voltage is proportional to rate of change of current.  So if you take 1ns to stop it, you'll get a huge spike.  Take a few milliseconds to turn it off, you'll probably get no measurable spike.  Too slow, or too small a MOSFET, and you'll burn up it up  - A high power MOSFET like probably "anything" in a TO-220 package should be adequate.