ZDoom

actor PistolZoom : Pistol
{
Weapon.SlotNumber 2
states
		{
		AltFire:
			TNT1 A 0 A_JumpIfInventory("Zoomed",1,3)
			PISG A 5 A_ZoomFactor(3)
			TNT1 A 0 A_GiveInventory("Zoomed",1)
			goto ready
			TNT1 A 0 A_ZoomFactor(1)
			PISG A 5 A_TakeInventory("Zoomed",1)
			goto ready
		}
}
			


Actor Zoomed : Inventory
{
	inventory.maxamount 1
	-COUNTITEM
}

Two things I can tell you right away. First, man, this formatting is really hard to read. Second, it's not a good idea to make the zooming state a 0-tic one (and in your case your zoom out state's length is 0). If you hold a button even for a bit, it'll zoom out, go into ready state and then right into zoom in state. Can't say anything else definite , but I threw together this and it works fine:

[code]actor PistolZoom : Pistol
{
Weapon.SlotNumber 2
states
{
AltFire:
TNT1 A 0 A_JumpIfInventory("Zoomed",1,3)
PISG A 5 A_ZoomFactor(3)
TNT1 A 0 A_GiveInventory("Zoomed",1)
goto ready
TNT1 A 0 A_ZoomFactor(1)
PISG A 5 A_TakeInventory("Zoomed",1)
goto ready
}
}



Actor Zoomed : Inventory
{
inventory.maxamount 1
-COUNTITEM
}[/code]

So I am actually working on a project, and I've done a weapon with sights.

The problem is that when I press the altfire button first time, gun becames aimed, but when I press Altfire second time, it doesn't go to Ready state, but instead it flickers and stays aimed.

Here's my lump:
[spoiler]ACTOR Sights: Inventory
{
Inventory.MaxAmount 1
}

ACTOR BioPistol: Weapon
{
Weapon.AmmoType "Clip"
Weapon.AmmoGive 60
Weapon.AmmoUse 1
AttackSound "Pestol/pew"
Weapon.SelectionOrder 10
Weapon.SlotNumber 1
Inventory.PickupMessage "Got a Broadsider pistol!"
States
{
Spawn:
PSTP A -1
Stop
Ready:
PSTL A 0 A_JumpIfInventory("Sights", 1, "ReadyA")
PSTL A 1 A_WeaponReady
loop
Select:
PSTL A 1 A_Raise
loop
Deselect:
PSTL A 0 A_TakeInventory("Sights",1)
PSTL A 0 A_ZoomFactor(1)
PSTL A 1 A_Lower
wait
Fire:
PSTL A 0 A_JumpIfInventory("Sights", 1, "FireZ")
PSTL B 3 A_FireBullets(5,5,1,10)
PSTL CD 3
PSTL A 0 A_Refire
goto Ready
Altfire:
PSTL A 3 A_JumpIfInventory("Sights", 1, "ZoomN")
PSTL A 3 A_GiveInventory ("Sights", 1)
PSTL A 0 A_ZoomFactor(3)
goto Ready
ReadyA:
AIMP A 1 A_WeaponReady
loop
ZoomN:
TNT1 A 0 A_TakeInventory ("Sights",1)
TNT1 A 0 A_ZoomFactor(1)
goto Ready
FireZ:
AIMP A 3
AIMP B 3 A_FireBullets(3,3,1,15)
AIMP C 3
AIMP C 0 A_ReFire
Goto ReadyA
}
}[/spoiler]