No problem here expanding the knowledge base.
Martini rifles are very interesting and are a great way for a budding collector to get into a genuine 19th Century rifle in either a BP cartridge or the 303 British.
They are not without their limitations though.
In fact, the fat squat 577/450 cartridge came about in order to allow a .45cal cartridge with a big powder charge to "get around the corner" in the Martini action. This is mentioned in your link.