Rifling

Basic Information

Rifling is the series of spiralling grooves carved into the inside of the barrel of any firearm which isn't smooth bore. A round fired along the barrel engages with the rifling, either directly or by means of a wrapper (such as the leather patch used in early rifle-muskets) or a driving band (as in some modern artillery shells). Once engaged the round turns as the groove turns, setting itself spinning around it's long axis and the resultant spin evens out any small inconsistencies which would otherwise push it off target, thus greatly increasingly the accuracy of the shot.

The number of grooves and the tightness of the spiral (and thus the resulting spin speed of the round) are much debated and experimented on with different gunsmiths having different opinions on what composition is best.

The introduction of rifling made smooth bore weapons obsolete for most purposes, although the two principles co-existed for a time since a muzzle loading weapon could be reloaded faster if it was a smooth bore due to the much tighter fit required to allow a rifle ball to grip the rifling. Breech loading removed this advantage and left the rifled weapon clearly superior for all but a few applications.

Rifling gave it's name to the rifle (originally the rifle-musket), but as noted above is found in pretty much every modern weapon except the shotgun and a few types of ordnance.

Sources

Bibliography

1. full source reference

Game and Story Use

• Note that rifling on a weapon wears out over time, more or less proportionately to the number of rounds fired - using corrosive primers, firing large numbers of harder rounds (such as a lot of armour piercing) or letting the barrel overheat (and thus soften) by sustained firing all accelerate this process. Weapons can be re-bored and/or re-lined but replacement is often easier, especially for small arms.
  • Thus, an elderly or poorly maintained weapon may well have its "bore shot out" and so be less accurate and less powerful (and possibly more prone to stoppages).
    • Counterfeit Soviet weapons are particularly prone to this - WarPac recognised a long time ago that the corrosive primers that are (or at least were) standard on their ammunition would strip the rifling of a normal steel barrel in quick time, so they took to chrome plating the inside of their barrels. The sort of people who make counterfeit versions - usually in places like the Pashtun Hills (where the "Pass made" knock-off rifle is as old as there being brand-name rifles to knock off that have been seen in the region) - have neither the technology, understanding nor inclination to copy this chroming process and so their products tend to suffer badly when used with standard WarPac ammo.
  • This is important after the end - weapons that have been in continuous use for centuries - assuming that they haven't failed or run out of ammunition (perhaps because they are using post-lapsarian improvised rounds) are likely to be more or less smooth bore and their users may consider tails of accuracy in bygone times to be mere heroic legends. A factory fresh weapon, properly stored over the same period, and then retrieved and put back into action by someone who knows what they are doing could seem downright magical. Especially with a supply of original ammunition.