Currently, RAW, a single shot from any gun that misses does not have the capability to suppress via Ammo Dice.
This has been discussed in the Discord over the last few days and I wanted to get people's opinions on this here as well.
Currently the "fix" for this that we've come up with is to just have players always roll 1 ammo die, even if they're firing a single shot. A success on the ammo die will still suppress, even if they miss the main attack roll. Right now it's better to fire at 1 ROF, miss, and suppress on a 6 on the Ammo Die, than it is to choose to fire once and possibly miss.
This benefits snipers taking single shots at targets. Getting shot at by a high power weapon is a big deal, and it just feels wrong for a sniper to spend a round lining up a Sniper Aim action only to miss and... have nothing happen? Like how far over the targets head does that round go that a miss doesn't have a chance to suppress.
Ovbiously saving ammo is a argument for not always rolling 1 ROF, but is the Suppression trade off really worth it? Suppression as a game mechanic is very powerful, taking someone out of the fight for a round or 2, doubly so for Panic Spreading.