Nice catch! Never paid attention to this.

Do you have an approximate of the changed results, as in, an excel sheet or a table with old formula and new formula average example results based on 20 shots for instance? (That's how I change formulas usually)

Nope, data is not really my thing, I just wing it and test if it works in game.

In brief, old formula has a 20 in 1000 probability to damage an internal part by 5-12% condition.
New formula has a 240 in 1000 probability to deal 1% damage.

Also with new formula barrel degradation is 40% slower for guns like AK, but 300% faster for big guns like shotguns.
This results in ~40% faster internal parts degradation or ~32% faster total degradation (I believe old degradation was way too slow + it's slower on lower economy difficulties now (0.5, 0.75. 1.0))

Ok. I'll run some tests and decide to add it or not thanks :)

I believe that since barrels are more difficult to replace, they should degrade notably slower than internal parts.