But my biggest gripe is that this +5HP translates to about zero difference in gameplay.
I honestly don't feel this way. The buff in HP is rather noticeable (though not as much as EXALT's armour).
"Nobody bothered to correct me" is not an argument. You really need to familiarise yourself with how iconic firearms look if you're going to make a 'gun porn' mod.
It's not an argument, I LITERALLY ASKED YOU IF YOU WERE SURE.
I've never even heard of these guns before someone gave me the graphics... Honestly, who knows all this crap by heart? Why? I wouldn't have imagined it before releasing XCF...
I might do something about it if I have the energy to do so, but honestly, this is not something I expected to be a
thing. I don't think more than a few people I knw can tell a difference between a pistol and a revolver, and here I get bombarded with all this meaningful nitpicking. Then again, factual accuracy is important to me...
What's next, complaints about alien physiology not conforming to PhD level biology because enzyme X cannot do Y?

But, okay: Sten, Sterling. Note the barrel shroud.
WTF is a "barrel shroud"?
Now, the Sten gun did come in a few different marks. The above is the most popular and iconic one, Mark II. Mark III did look a lot more like the bigob. But none of them had that exact kind of perforated barrel shroud (though Mark III came close and some others could have somewhat similar sound suppressors).
Can't say they're much different (as both look like scrap with a metal bar), but okay