
Prerequisite: Strength 13 or higher.
You have learnt to use your weapons in multiple ways, and you are particularly adept at converting a glancing blow into a back-swing when you use swords, maces, and similar one‑handed weapons.
- When you deal damage with a melee weapon you can decide if it deals bludgeoning, slashing, or piercing damage.
- Once per turn when you miss a creature with an attack using a melee non‑finesse weapon, you have no weapon in the other hand, and you didn’t roll a natural 1, that creature takes 1d4 bludgeoning, slashing, or piercing damage.

Weird limitations, in addition to problems with the design. Also, it's actually not very powerful; the average DPR increase would be 1.25 if you only hit half of the time, and most players hit more than that, and D&D 5E has so few physical damage resistances/vulnerabilities that I doubt it would be useful to be able to change it very often.
Thank you for the feedback, much appreciated.
I agree with you: physical damage resistance is really not so relevant in 5e, and the correction to the damage output doen't make up dor that or the expenditure of a feat.
I still want to have a weapon specialization feat for non-finesse one-handed weapons in the pool, so I will probably upgrade this feat in some ways. Either upgrading the damage on a miss to your Strength modifier (even less die rolling and a more reliable output) and/or removing the "unless natural 1" clause, or adding an extra ability to the feat.