Given the description, it's obviously not a bug.
As for getting 20 strength, you can totally do it. I think with the right drugs and food you can get about 21? Mushroom brew, adrenaline, supersoldier makes for +5, there's probably gear ways of getting higher.
You also don't need to have the required strength to wield it, it just makes it less accurate, and accuracy isn't going to be a problem if you max melee with like 16 strength lol. I'm only disappointed that it doesn't do much damage, a shock hammer is still superior.
