Will they fit?

The Gangster from Collectible Minifig Series 5 comes with a folding violin case and a Lego pistol that fits into it. I was very disappointed to find that the case is too small for either the M1A1 or the newer Tommy Gun, even with the drum detached from the latter. So I set about trying to figure out which BrickArms you could get into the case. The results were not always what I expected!

 

Here is an assortment of the smallest BrickArms firearms, along with my modded sawed-off SABR. Most of the weapons pictured here fit and will allow the case to close cleanly. A few don't and won't. If it's not pictured here, it blatantly doesn't fit in some way.

 

Can you guess which ones don't? The answers might surprise you.

 

Read through the comments or try it yourself to find out.

Done