Looking for a source for MG42 decreased rof

In basically every argument about MG42’s rof someone writes that Germans decreased it for infantry use. But are there any proofs of this happening? Personally I never saw any sources stating this, quite the contrary.

(I’m not asking if this is possible.)

Just made a simple google search on it, found that the rof can be decreased to replacing its bolt for a heavier one. But no reports of it ever happening during the war.

That’s what I saw too. Many sources say that it’s possible but none say it was actually done.

German change bolt in Mg-42 to heavy bolt for discount rate of fire for safe barrel with overheat. Mg-42 heavy bolt (Rof 960) is complete version for mass product.

Great. Now give me your source.
Because dude writing something on a game forum doesn’t count as one.