|Rifled Cannons (Empire: Total War)|
|Prerequisite||Carronades, Machined Rifling|
|Research Points Needed|
|Building Needed||Naval College|
|Leads To||Sheet Lead Cartridges|
Rifling a barrel increases the accuracy of a weapon, and this principle can be applied to large cannons as well as small arms.
Ordinary naval cannons are smoothbore weapons, meaning that the barrel is a simple tube to contain the explosion. The limitations of casting mean that cannons are quite crude and windage, the gap between the barrel and shot, is always a problem. A shot often "rattles" down the barrel when fired, making it inherently inaccurate. The loss of accuracy with a smoothbore makes its maximum range of academic interest only, simply because it becomes a matter of luck rather than judgement to hit anything far away!
A rifled cannon solves these problems. By using machines to bore out the barrel from a blank casting, one inaccuracy is removed. Another machine cuts a helical pattern of grooves into the barrel wall. This imparts a spin to any shot as it travels down the barrel, and a spinning projectile flies true. This makes the effective range of a rifled cannon shot much greater than one from a smoothbore, although the maximum range for both is similar.
Historically, rifled cannons used manufacturing techniques developed for making accurate steam pistons and cylinders.
Rifling makes cannons significantly more accurate, particularly at longer ranges. However, despite in-game descriptions, it does not increase the maximum range for any ship.