New packaging label requirements from C.I.P. regarding polygonal barrels
The C.I.P. organization, which decides on the safety and standardization of weapons and cartridges, has decided on a requirement for cartridges loaded with solid bullets harder than lead (e.g. solid copper or brass) to carry a warning on the packaging that they should not be used in polygonal rifled barrels.
What is a polygonal barrel?
Polygonal rifled barrels do not have traditional sharp lands and grooves. Instead, the bore cross‑section is shaped like a smooth polygon with rounded corners. The interior looks like a rounded polygon rather than a circle with cut grooves.
Polygonal rifled barrels are allowed a slightly narrower free bore area than normal rifling. This can increase the pressure with solid bullets harder than lead bullets, which is why the warning has been deemed appropriate.
In hunting rifles, this rifling is very rare; it is most often used in serial firearms and self-loading pistols (e.g. Glock). However, this rifling can be encountered in old self-loading H&K hunting rifles.
Lapua is placing a warning icon on Naturalis and TRX cartridge and bullet packagings (see lower right corner of packaging in picture below). No changes have been made or will be made to the bullets or cartridges, it is only a new marking to the box printing.
