test firing & reliabilty
I always field strip and inspect a new gun and clean it and lube it, the owner should know how to do this before firing.
You dont need to fire a 1000 rds to see if it's reliable, if you can fire 200 rds without a problem that should be fine, your never going to fire a 1000 rds during a gun fight / Home Defense situatiuon
just test a box of the ammo you plan on using for defense
I hear a lot of people say they wont trust a gun or use it as a carry gun unless they shoot at least 3,000 rds through it first, etc, in my opinion this is not necessary, your wasting your money, thats a lot more than the cost of the gun
I consider a gun to be very reliable if you can fire 500 rds of various types with no problems, just a few trips to the range.
you probably wont even shoot one magazine for defense.
I also try several types / brands of ammo to test reliability & function with different brands
most of my new handguns have been tested with at least 12 - 15 different types of ammo, different bullet weights, steel cased, aluminum, brass, JHP defense loads, reloads.
Im confident my guns will take just about anything I use in them.
and always make sure to test a new gun on paper targets first to check the sight alignment & accuracy at various ranges, in case it might need some adjustments.