[LionofPerth]

In the house rule at our table you can actually use SMGs with both skills. Pistol Skill when you wield it in one hand ("gangsta style" which is seem to be the "norm" in the SR universe) and Longarm skill when you use it with both hands (we also ruled that in order to get the benefit of the extra point of recoil compensation from a folding stock you need to wield the SMG with both hands "spec op style").

And now, I must have a character threaten to "shoot someone spec-op style" 

I think that's an actual method firing some weapons without stocks. You've got a sling and you're holding it in both hands.

I say think, as I don't have strong evidence for it. Perhaps it's time for some googling,

[martinchaen]

While I've never heard it referred to as "Spec-ops style", using a sling to increasing stability when firing a submachine gun is a tried and tested method, though not nearly as effective as an actual stock (collapsible, solid, or otherwise).

During my service, I was trained to use the sling to assist when firing a rifle; we were taught the loop sling and the "hasty" sling methods. I'm quite certain one can find plenty of videos describing how to accomplish these on youtube.

[LionofPerth]

While I've never heard it referred to as "Spec-ops style", using a sling to increasing stability when firing a submachine gun is a tried and tested method, though not nearly as effective as an actual stock (collapsible, solid, or otherwise).

During my service, I was trained to use the sling to assist when firing a rifle; we were taught the loop sling and the "hasty" sling methods. I'm quite certain one can find plenty of videos describing how to accomplish these on youtube.

Or someone has been trained in a similar method. Thanks for the confirmation.