I changed some Feats in my home-game after I got asked for feedback and less powergaming. So I introduced the following changes:

Heavy Armor Mastery
Prerequisite: Proficiency with heavy armor

• Increase your Strength score by 1, up to maximum of 20.
• While you are wearing heavy armor, bludgeoning, piercing, and slashing damage that you take is reduced by your proficiency modifier.

Great Weapon Master

• On your turn, when you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you can make one melee weapon attack as a bonus action.
• Before you make a melee attack with a heavy weapon that you are proficient with, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add double your proficiency bonus to the attack's damage.

Sharpshooter

• Attacking at long range doesn't impose disadvantage on your ranged weapon attack rolls.
• Your ranged weapon attacks ignore half cover and three-quarters cover.
• Before you make an attack with a ranged weapon that you are proficient with, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add double your proficiency bonus to the attack's damage.

What I have seen before for Sharpshooter and Great Weapon Master is taking your removing your proficiency bonus to hit and doubling it for damage. I think that might be an effective way to still get the "big hit" but also have it scale with level as well. I haven't tried it, so I am not sure how good it is.

Quote from ArchSeshiro >>

What I have seen before for Sharpshooter and Great Weapon Master is taking your removing your proficiency bonus to hit and doubling it for damage.  

I dont want Sharpshooter to be a no brainer, and starting with prof bonus at 2, it would only be a -2 to hit and a +4 damage, which gets completly negated by archery fighting style

anyone else able to give feedbakc or already has used something similar?