Muzzleloaders and proofing

[GM54-120]

While some companies have done it, at least with the barrels. Its somewhat hard to find any info because SAAMI does not handle MLs at all. GMB told me their barrels for Knight were tested to over 50kpsi but who knows?

The only company ive seen go above and beyond has been Pedersoli if they are not just "blowing smoke". They claim to test every single black powder firearm while its assembled. Not just using a test plug in a barrel which is required under Italian laws.
https://www.davide-pedersoli.com/ri...-us-rifle-muskets-in-the-1860s-and-today.html
Notice the proof load they use for the musket.... OUCH

The proofing started with installing the proofing-plug and loading the first proof load: 280 grains of the same musket powder used for the normal cartridges, an over powder wad, a 500 grain ball and an overshot wad. The charge was rammed with a copper loading rod. If the barrel did not burst, it was time for the second load of 250 grains of musket powder, wad, 500 grain ball and wad again. If the barrel remained intact, it received the inspection marks: “V for viewed, P for proved with the eagle's head under them, placed on the left square of the barrel, opposite the cone seat. The barrels will be immediately washed clean in hot water and dried after which they will be again carefully examined.”

The cleaned barrels were inspected again, and condemned is necessary. The bores were straightened again, and prepared for the final assembly.

Today the replica manufacturers have a more difficult task is they want to meet the high standards of CIP (Permanent International Commission) proofing. The CIP lays down common rules and regulations for the proof of weapons and their ammunition in order to ensure the mutual recognition of Proof Marks by its member states. Fourteen countries are CIP Member States.

Each and every blackpowder firearm must pass a pressure proof test in the official CIP proof house of Gardone to receive the modern blackpowder proof marks. The official modern proof loads for .58 caliber rifles are quite close in weight to the 19th century proof loads being 15 g (231,5 grain) of blackpowder and 39 g (601 grain) in bullet weight. But the powder used today is much hotter than the 19th century U.S. Government musket powder (the modern proofing powder is the Swiss No. 2. 3Fg powder which is finer and stronger) and the barrels are not proofed in proofing machines but in the fully assembled (but white finish stage) rifles. After firing the barrel, the breech and the stock are inspected for any kind of cracks and damages. Only the spotless rifles will receive the final proof marks and only these rifles qualify for shipping to the customers all over the World.

Balázs Németh

Notice the first and last 5 words in the last paragraph. Italy has some of the strictest proofing regulations of any country