What is a convincing way to get a fake blood splatter?

Worse and cheapest case, if it's going for a b movie troma type thing, use a car sponge. Soak it in your fake blood and one good quick squeeze will do it. Plus a gunshot wound wont really splatter if you're going for realism, but due to arteries it will bleed alot. So spatter b movie etc. Car sponge....realism, semi spatter and a shot of the victim holding the crotch area and lots of blood around it.

Depends on how much blood you're going for. What kind of splatter, etc. A balloon squeezed (popped), a flexible tube that you can just put something to obstruct the end a bit and blow in or use a compressor. Just depends on how realistic you want it and what you have access to

Got a bottle of Windex or some other spray type bottle? Some of them have a stream/spray option that should do what the pesticide sprayer would do.

northernroses do you have any joke shops they will sell it

thinned ketchup maybe/ziplock bag with holes

Try those Halloween stores...they have the stuff.

Bat blood 😏