I was messing around with a point_entity_spawner, but I couldn't make it spawn a portal gun! Has anyone done this successfully?

I think we need a little more info on what you're trying to do.

Do you want to spawn multiple physics-based portal guns, that the player won't be able to pick up?
Do you want to spawn just one weapon at a particular time, that the player can pick up?

I'd like multiple portal guns that the player can pick up like a normal gun. Also, the weapon_portalgun entity apparently can't activate triggers, and I need them to do that.

I jury-rigged a solution using a prop_physics_override, point_entity_template, and a point_clientcommand, but I can't make the gun be picked up when walked over.

You can activate trigger when the player pickup the gun: OnPlayerPickup

And I don't know why the hell you need to spawn multiple portal guns but try to use the point_template. Refer a real weapon_portalgun you placed in the point you want it to spawn into the point_template, and then trigger the point_template using ForceSpawn multiple times.

I'm making a conveyor that "packages" an endless stream of guns. (In reality, a trigger_remove just kills the gun and spawns a box.) The problem is that weapon_portalguns don't trigger a trigger_remove. Do you know any way around this?

Oh, and the OnPlayerPickup trigger triggers when the player picks it up with the 'E' button. I guess I'll have to use a trigger_close, or whatever that thing is.