Why do these bullets pause for about 0.1 seconds when shot?

local RE  = game.ReplicatedStorage.RemoteEvent

RE.OnServerEvent:Connect(function(p,m,Tool)
		local bullet = game.ReplicatedStorage.Bullet:Clone()
		bullet.Parent = workspace
		bullet.Size = Vector3.new(1,1,1)
		bullet.CFrame = p.Character:FindFirstChild(Tool.Name):FindFirstChild("Handle").CFrame
		bullet.CFrame = CFrame.new(bullet.Position, m)
		bullet.CanCollide = false
		local BV = Instance.new("BodyVelocity",  bullet)
		BV.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
		BV.Velocity = (m - p.Character.HumanoidRootPart.Position).Unit*600	
end)

--p = player
--m = Mouse.Hit.p
--Tool = The tool.

I shoot with the gun, it goes a bit in the direction it should be, then it stops for around 0.1 seconds, then continues. any way to fix this?

This is caused by the Network Ownership system. Every physically-simulated object in the game is automatically assigned a Network Owner that handles the object's physics calculations, and then replicates them to the server/other clients. Even if you instantiate the object on the server, the Network Owner may be automatically set to the nearest client. As the bullet travels further away from the player, the Network Owner changes from the client to the server, again, automatically. Every time a physically-simulated object switches Network Owners, there's a "hop" in the object's physics simulation. This "hop" is the amount of time it takes for the Network Owner to be switched, usually dependent on the latency between the old owner and the new owner.

I would suggest, anywhere in your code after creating the bullet, manually setting the bullet's Network Owner to the server. Manually setting a Network Owner will ensure that it's not automatically changed.

You can do this like so: bullet:SetNetworkOwner(nil)

Passing nil to BasePart:SetNetworkOwner() will set the owner to the server. Otherwise, you can pass a Player object to it and it'll set the Network Owner to that player.

This information comes directly from this article, if you want a more in-depth explanation.