Deleting one object at a time every 5 seconds Cocos2d - objective-c

Question

I have a problem with my cocos2d game. I am trying to delete a projectile shot by an enemy every 5 seconds (each projectile is supposed to have a lifetime of 5 seconds), but I cannot figure out how to do it. I get the error of
Assertion failure in -[CCTimer initWithTarget:selector:interval:]
Here is my code:
-(void)projectileShooting:(ccTime)dt
{
[self schedule:#selector(projectileShooting:) interval:2.5];
projcount++;
if([proj count] <= 15 ){
if(enemy1.position.y < 320){
v = ccp(player.position.x,player.position.y);
for(CCSprite *enemies in enemy){
CCSprite * projectilebullet = [CCSprite spriteWithFile:#"Projectile.png"];
[proj addObject:projectilebullet];
[self addChild:projectilebullet];
CGPoint MyVector = ccpSub(enemies.position,player.position );
MyVector = ccpNormalize(MyVector);
MyVector = ccpMult(MyVector, enemies.contentSize.width/2);
MyVector = ccpMult(MyVector,-1);
projectilebullet.position = ccpAdd(enemies.position, MyVector);
for(CCSprite *projectile in proj){
[self schedule:#selector (deleteprojectile:projectile:) interval:5];
}
}
}
}
for(CCSprite *enem2 in enemytwo)
{
if( [proj count] <= 15){
CCSprite * projectilebull = [CCSprite spriteWithFile:#"Projectile.png"];
CGPoint MyVector = ccpSub(enem2.position,player.position );
MyVector = ccpNormalize(MyVector);
MyVector = ccpMult(MyVector, enem2.contentSize.width/2+10);
MyVector = ccpMult(MyVector,-1);
projectilebull.position = ccpAdd(enem2.position, MyVector);
[self addChild:projectilebull];
[proj addObject:projectilebull];
for(CCSprite *projectile in proj){
}
}
}
}
-(void)deleteprojectile:(CCSprite *)protime:(ccTime)dt{
NSMutableArray *timepro = [[NSMutableArray alloc]init];
[timepro addObject:protime];
for(CCSprite *objecttime in timepro){
[proj removeObject:objecttime];
[self removeChild:objecttime cleanup:YES];
}
}

Answer 1

It's a bit of a hack but this is what I use in my program, until I find a more elegant solution. I have a method in my game layer that I call to remove a node from its parent, like so:
-(void)removeNode:(CCNode*)node {
[node removeFromParentAndCleanup:YES];
}
And when I want to schedule a node for deletion after a delay, I call it like this:
[self performSelector:#selector(removeNode:) withObject:node afterDelay:delay];
Simple, and it works.

Answer 2

Change argument name in your selector to protime instead of projectile. The selector must match the signature defined in you object's class definition.
Your selector was not defined properly and probably the Timer is checking if the object implements the given selector.
I did not have time to test it so thanks to #RamyAlZuhouri for confirming.