In documentation I found that RP-3 rockets are supposed to contain 14lb of TNT (instead of the 12lb in-game). this would make them just slightly better and more bearable.
In short, the extra TNT would allow for 50mm of penetration, letting the RP-3 stay relevant at and above 6.7 so we don’t just have to spam bombs.
The pages are not numbered, so this comes from about 80% of the way through the document under “General Description” of “60 lb Shell - SAP/HE, and Practice”
Search for “T.N.T.” - not TNT.
You would be “amazed” by this?? Easily impressed are you??