What are Napier cloths 450,? I have a silica packet in there. Usually it happens to the guns used most, the Bosis is fine, it only goes to the UK on pheasant shoots but a Perazzi SCO I have in there which goes to the range every week and is always kept oiled (as are all the guns) always gets
surface rust on it on the lock plates (bulimo engraving and a coin finish are a death knell here), under the safety etc, as it gets up to 45 deg C every summer and you sweat your balls off I guess that doesn't help, still, they are tools and I do the best i can to keep them OK, rgds, Mike