Help and opinions on 303 Brit PP 60

I am familiar with Prvi Partizan ammo and its headstamps. My newer stuff in Brit 303 says made in Serbia and the stamp is PPU. And says in English Script .303 British.
A box was recently given to me and the headstamp reads PP, VII, and 60. The VII means 170 plus grains of a standard Brit military load and the 60 is likely the year of production.
My question to anyone who may know; Is this ammo corrosive? I have read in the past that some PP ammo was loaded with nitro/ cordite/ guncotton mixture that is corrosive even though the primers may not be. The guy that gave me this stuff has an Enfield #4 Mk 1 that he asked me to look at that I found to be quite rusty in the barrel. I spent about four hours getting the crap out of the barrel and action. A few days later he gave me the gun and about 50 rounds of this ammo. I don.t know if this was the ammo that caused the barrel issue but I it would be a likely assumption.
My own 1948 (PF) LE #4 Mk 1 is in beautiful shape and I don’t want to run this stuff down range with out having a high comfort level with it.
Any help will be appreciated.

So long as you clean your rifle, it makes no difference what ammo you use. I probably have over 100 types of .303 ball, and none of it causes any corrosion in the hours between shooting and cleaning.

Fairly sure all of the PPU production over the years has used nitro powders.

Rule of thumb, if you have doubts then treat it as corrosive. That way you are covered either way. After firing corrosive I do the water swab/normal cleaning/oil it up treatment and have never had an issue.