At a minimum you will want something with a firmly anchored barrel band (or a barrel and receiver built like a tank but those are rare). Regarding dust, your best bet is to go with a dry lubricant on the bolt and hammer.
DIRT /DUST is NOT OUR FRIEND with any PCP or Spring guns !!!!!!!!!!!!!!Being an Air Tech servicing over a 100 air rifles a year I get to see first hand all the nooks and crannies garbage can get into
The most interesting man in the world is alleged to have said, "I don't often use an air rifle as a club, but when I do, I prefer a springer"
DIRT /DUST is NOT OUR FRIEND with any PCP or Spring guns !!!!!!!!!!!!!!Being an Air Tech servicing over a 100 air rifles a year I get to see first hand all the nooks and crannies garbage can get into and F-up our beloved air guns.Indeed designs change with differing manufactures and there are certainly more that categorize as somewhat fragile to VERY fragile than are trending towards tough or near bullet proof ..... IMOToughest of the tough, least susceptible to debris ingress and just one solid mechanical assembly ... The TAIPAN's be them older Mutants or the newer Veterans.Being a bullpup there short and compact making for a most excellent "Truck Gun" Don't shoot the messenger