This is a minifigure scale (ish?) Nerf gun I designed a while ago. A minifigure should be able to hold it by the handgrip as well as the spring pull-back part I don't know the name of.
I've printed most of mine in a vertical orientation with the barrel facing up. Support set to touching buildplate.
Layer time hasn't been an issue for me, but printing multiple ones at a time could help if you're getting gummy heat-soaked layers towards the top. Just make sure your retraction is dialed in, stringing has ruined a couple of these for me.
UPDATE: Added a revised file with tighter tolerances for resin printing! Enjoy!
The author marked this model as their own original creation.