Letty

(edit: killing useless wall of text)
I recommend when practicing to try over a bed at first, in case you drop them.
 
The following is provided in a step-by-step fashion for pedagogical purposes. Once you get a feel for how a Strongarm feels in motion (or even in midair), you can abbreviate and style up as you please.
 
 20160726_204416.jpg   41.69KB   66 downloads  20160726_204433.jpg   44.45KB   65 downloads  20160726_204450.jpg   33.78KB   66 downloads
First three images illustrate the hand size requirements. If you're looking to try this technique out and getting a Strongarm for this purpose, try the following grip on a boxed Strongarm in the shop before you purchase.
 
 20160726_204550.jpg   43.97KB   76 downloads
1. A basic grip.
 
 20160726_204604.jpg   45.91KB   79 downloads
2. Flick the blaster such that it rests in the palm of your hand, as if Cradling it. Note the thumb position securing the blaster to your palm.
 
 20160726_204614.jpg   38.71KB   65 downloads
3. Flick one more time, this time catching the end of the slide under your index finger and engaging it. You squeeze the blaster between your thumb and forefinger to hold most of its weight. The rest of your hand does the rest.
 
 20160726_204624.jpg   36.49KB   68 downloads
4. Squeeze to cock, then reverse the previous to return to basic (flick, flick).
 
When accustomed to technique, can switch grips in one flick, and in any position (down, going up, to sides)

Also see imgur gallery: http://imgur.com/a/NBzqu