omit everything before paragraph (b), substitute
4 Not firearms—Act, s 4, def firearm
(1) In this regulation:
"pre-percussion pistol" means a muzzle-loading pistol (including a percussion lock pistol that is muzzle-loading) that uses black powder to propel a projectile, but does not include any breech loading pistol with a rotating cylinder or any other breech loading pistol that accepts metallic cartridges.
(2) The following are declared not to be firearms:
(a) a pre-percussion pistol;
(b) a firearm (other than a percussion-fired pistol) manufactured before 1900 for which ammunition is not readily commercially available;