How to make a script check for a collision?

How can I get a script, like a gun, when it shoots a wall, the bullet detects the collision and deletes it self. All I am asking what type of coding do I need to check for a collsion with anything named "Brick"??

Gun Script (Only got the main parts youll need to see)

    local missile = Instance.new("Part")

    local spawnPos = vCharacter.PrimaryPart.Position

    spawnPos  = spawnPos + (v * 10)

    missile.Position = spawnPos
    missile.Size = Vector3.new(1,1,1)
    missile.Velocity = v * 300
    missile.BrickColor = BrickColor.new(26)
    missile.Shape = 0
    missile.BottomSurface = 0
    missile.TopSurface = 0
    missile.Material = Enum.Material.Plastic
    missile.Elasticity = .05
    missile.Friction = .7
    missile.Name = "Bullet"
    missile.CanCollide = true

I thought I would just add the whole gun script. Sorry if it is long. Most of it is just variables, probably go down to line 100 around their would be the shooting part

local Tool = script.Parent;
local reloading = 0

enabled = true

local reloadSound = Instance.new("Sound")
reloadSound.Name = "reloadSound"
reloadSound.SoundId = "http://www.roblox.com/asset/?id=13510737"
reloadSound.Parent = Tool.Handle
reloadSound.Volume = 2

local reloadSound2 = Instance.new("Sound")
reloadSound2.Name = "reloadSound2"
reloadSound2.SoundId = "http://www.roblox.com/asset/?id=25299064"
reloadSound2.Parent = Tool.Handle
reloadSound2.Volume = 2

function fire(v)

    local vCharacter = Tool.Parent
    local vPlayer = game.Players:playerFromCharacter(vCharacter)



    local noise = Vector3.new(math.random() - .3, math.random() - .3, math.random() - .3).unit

    v = (v + (noise * .03)).unit

    local missile = Instance.new("Part")

    local spawnPos = vCharacter.PrimaryPart.Position

    local PewPew = Tool.Handle:FindFirstChild("PewPew")

    if (PewPew == nil) then
        PewPew = Instance.new("Sound")
        PewPew.Name = "PewPew"
        PewPew.SoundId = "http://www.roblox.com/asset/?id=13510352"
        PewPew.Parent = Tool.Handle
        PewPew.Pitch = .5
        PewPew.Volume = 10
    end

    spawnPos  = spawnPos + (v * 10)

    missile.Position = spawnPos
    missile.Size = Vector3.new(1,1,1)
    missile.Velocity = v * 900
    missile.BrickColor = BrickColor.new(26)
    missile.Shape = 0
    missile.BottomSurface = 0
    missile.TopSurface = 0
    missile.Material = Enum.Material.Plastic
    missile.Elasticity = .05
    missile.Friction = .7
    missile.Name = "Bullet"
    missile.CanCollide = true
    missile.Transparency = 1

    local force = Instance.new("BodyForce")
    force.Name = "BulletFloat"
    force.force = Vector3.new(0,99,0)
    force.Parent = missile

    local creator_tag = Instance.new("ObjectValue")
    creator_tag.Value = vPlayer
    creator_tag.Name = "creator"
    creator_tag.Parent = missile

    local new_script = script.Parent.LaserBlast:clone()
    new_script.Disabled = false
    new_script.Parent = missile

    missile.Parent = game.Workspace

    PewPew:Play()

end

function gunUp()
    Tool.GripForward = Vector3.new(0,.981,-.196)
    Tool.GripRight = Vector3.new(1,0,0)
    Tool.GripUp = Vector3.new(0,.196,.981)
    script.Parent.Fire.Fire.Enabled = true 
    script.Parent.Fire.LSmoke.Enabled = true
    script.Parent.Fire.Smoke.Enabled = true
    wait(0.000000000000000000000000000000000001)
    script.Parent.Fire.Fire.Enabled = false
    script.Parent.Fire.LSmoke.Enabled = false
end

function gunOut()
    Tool.GripForward = Vector3.new(0,1,0)
    Tool.GripRight = Vector3.new(1,0,0)
    Tool.GripUp = Vector3.new(0,0,1)    
    script.Parent.Fire.Smoke.Enabled = false

end

function isTurbo(character)
    return character:FindFirstChild("BoltHelm") ~= nil
end


function onActivated()
    if not enabled  then
        return
    end

    enabled = false

    local character = Tool.Parent;
    local humanoid = character.Humanoid
    if humanoid == nil then
        print("Humanoid not found")
        return 
    end

    local targetPos = humanoid.TargetPoint
    local lookAt = (targetPos - character.Head.Position).unit

    local reload = 2

    gunUp()
    fire(lookAt)

    reloading = reloading + 1
    if reloading >= 6 then
        if reloadSound ~= nil then
            wait(0.1)
            Tool.GripUp = Vector3.new(0,0,1)
            wait(0.1)
            reloadSound:Play()
        end
        reloading = 0
        Tool.GripUp = Vector3.new(0,0,1)
        wait(0.1)
        Tool.GripUp = Vector3.new(0,-0.2,1)
        wait(0.1)
        Tool.GripUp = Vector3.new(0,-0.5,1)
        wait(0.3)
        reloadSound2:Play()
        wait(0.3)
        reloadSound2:Play()
        wait(0.3)
        reloadSound2:Play()
        wait(0.3)
        reloadSound2:Play()
        wait(0.3)
        reloadSound2:Play()
        wait(0.3)
        reloadSound2:Play()
        wait(0.3)
        reloadSound:Play()
        wait(0.1)
        Tool.GripUp = Vector3.new(0,-0.2,1)
        wait(0.1)
        Tool.GripUp = Vector3.new(0,0,1)
    end

    wait(reload)
    gunOut()
    wait(reload)

    enabled = true

end

function onEquipped()
    Tool.Handle.EquipSound:play()
end

script.Parent.Activated:connect(onActivated)
script.Parent.Equipped:connect(onEquipped)