Fact was in WWI the attrition rate for 303's from battle damage was measured in days as were the men, WWII I think was a few weeks but like BIO says and I can relate as well to our range rifles were fetted over in the cadets and whoa betide the chap who's 4 x 2 came out dirty after they tried to return it to the armory after range practice the QM was most displeased.

Thing is in all reality in today's world there is no real need to shoot the stuff not only will you get spurious results from old aged ammo but contending with the corrosive primers.
What some do here is pull the pill and renew all the explosive components powder/primer reload it and carry on.
But if you wish to shoot it thats fine just remember the cleaning regime and also cordite burns allot hotter than our smokeless powders so you will eventually toast the throat which does not aid accuracy somewhere in E B Reynolds book they go through sustained fire with a rifle and its a few thousands of rounds before the barrel was shot out.