I've been tasked with making a ranged paladin, and here are some ways that I'd do it.

Reflavor

I think I've done Ranger/Fighter reflavors - Eldritch Knights and Arcane Archers can easily reflavor their spells and magic into various types of smites. With a lenient enough Dungeon Master, you might get away with getting these spells to just straight up do radiant damage. They will however, lack healing capabilities without taking specific feats.

Rangers on the other hand, primarily have their hunter's mark spell to act like a smite. They have access to Cure Wounds and other healing spells to act as Lay on Hands and other healing spells. Even the Beast Master/Drakewarden class can simulate a steed potentially. 

However, with this player, we want to keep the primary features of a Paladin, such as the 2014 on hit Divine Smite, Divine sense and Divine Health abilities, and the Aura of Protection feature from both 2024/2014. 

Taking Other Homebrew

There are two Homebrew Classes I found online (1 and 2), both called Oath of the Arrow (dangit, that means I gotta come up with a unique name...).

Both have cool Tenets, and interesting choices for Oath spells and cool flavorful features, but let's summarise them.

Nine's Version

Nine's version (link 1) has Hunter's Mark (similar fix to the ranger), and more Ranger vibes for spell choices. The Channel Divinity ability of creating blessed ammunition is a fix for creating Smiteable™ ranged weapons. The extra 1d4 damage doesn't help it's case however of the primary reason against ranged Paladins - that is smite on a ranged weapon is incredibly powerful. While I am relatively flexible in my games, and I don't usually mind the Paladin's smites dealing 200+ damage in a round (recently ran Eve of Ruin, and a level 5 Divine Smite with Level 4 Blinding Smite on a Holy Avenger on a Crit was not on my bucket list this year) due to their limited spell slots, I personally find them more glass cannon-y than most. Regardless, it is fair that if a character can deal divine smite on an arrow, it could make some fights incredibly trivial. Throwing in an extra 1d4 is sprinkling overall, but doesn't help the case in this regard.

The ability to create a moving box is highly motivating for ranged characters, but I do feel like it's better used in parallel to another party member who is ranged, as opposed to the Paladin using it themselves. It's easier to keep the monsters back as a high AC paladin, while the presumably fragile ranged characters hide behind. I think the intent was for the Paladin to use it, but I might be wrong.

Their aura is another cool crowd control ability meant to encourage playing ranged for the Paladin, but I do feel like the flavor isn't what the player and I are looking for. Again, VERY cool ability. Might steal it for another player concept.

The level 15 ability lets you make Smiteable™  ammunition, up to your Charisma modifier, but Paladins can only really attack twice, so I don't see much value to this if you have more than +2 in Charisma.

The capstone ability goes ham, allowing the Paladin to hit an extra time, gain passive radiant damage, and cover for allies in their aura. Overall, a really HOLY ranged paladin, but not what we're looking for.

Carreau's Version

The spells have a mix of holy (Bless, Holy Weapon) and ranged themed spells (Zephyr Strike, Cordon of Arrows, Conjure Volley), and the first Channel divinity allows you to make Ranged Weapons Smiteable™. 

The second Channel Divinity allows ALLIES TO ATTACK as part of a coordinated attack. This is very cool. Make an attack with bonus radiant damage, but also your party can make attacks too. 

Level 7 gives ranged allies unlimited ammo and extra to attack and damage. It's pretty straight forward, and encourages more ranged players.

Cover Shot is a cool action economy management ability, and the capstone ability makes you an angel that can fly, attack an extra time, and crit on a 19. Goes ham, but in a kinda Fighter-y way. Still a cool angel effect!

What We're Looking For

Realized I've mentioned that "this isn't what we're looking for" but I haven't actually mentioned what this character is. The character is a gunslinging mercenary for hire, who has a sense of moral justice, and hence the Paladin side of the character. He lives in a world filled with Fae and Vampires who don't care for the mortal kind, and acts as an arbitrator between them and prevents outbreaks of fights and wars from happening. A Gunslinging Soldier of Holy Proportions.

Making Something New

I feel like Tenets will be what guide the abilities. This paladin doesn't feel like the all white paladin like with Devotion or Glory Paladins, and not so emo like Vengeance or Oath Breaker. We could make it more gray; perhaps an outlaw style/ronin gunslinger vibe. Bounties, punishment - this is reminding me of Dr. King Schultz a bit from Django Unchained.

Man, do we love a man with a gun

So, we definitely need (similar vein to the classes above) a way to infuse bullets with smites, and it needs to have some sort of limitation to keep it from being abused. A peaceful warrior who is forced to fight. Pragmatism, necessary ruthlessness, and a strong moral code. We'll pull up all the cowboy western tropes we can too, like Quickdraw, High Noon, and wielding two guns. The following will just be the mechanical text; of course in the final design we'll add flavor to guide players towards an aesthetic, but totally not necessary during the testing phases.

TENETS

Name the Guilty. Know who deserves punishment. Shoot them down, but not blindly.

Finish What You've Started. Once you have taken a bounty, it ends when the contract is done.

Strike Only Before Being Struck. Offer your enemies a chance to surrender and repent. A shot taken should be a shot deserved.

Explore the Frontier. Existence has no borders, and you are tasked to find it.

I'm really trying to lean into the whole west sheriff style for this character. Judge, Jury and (merciful) executioner.

Level 3: Oath of __________ Spells

Level 3 Ability - Channel Divinity

Warn the Wicked

As a bonus action, mark a creature you can see within 60 feet. For 1 minute, you may treat a single ranged weapon of your choice as a melee weapon for the purposes of imbuing them with Smite spells. Attacks with this weapon may only target the marked creature. If the creature dies during this duration, you may shift the Mark to another creature you can see within 60 feet as a bonus action.

(for 2024 Paladins) As part of this bonus action, you may cast the Divine Smite spell.

Quickdraw

When a creature attacks you or an ally within 30 feet of you and you haven't taken a turn yet, as a reaction you may use an attack action at advantage. If you do so, you may treat a single ranged weapon of your choice as a melee weapon for the purposes of casting Divine Smite on this weapon.

(for 2024 Paladins, again) As part of this reaction, you may cast the Divine Smite spell.

Warn the wicked will show the enemy that inevitable smites are coming, whilst maintaining the balance to one creature per combat (once to thrice per day, depending on level). This means that the Paladin actively has to think about whether they want to use this alpha strike or not. If they don't, they'll have to think about conserving spell slots for when they do wanna use the ability.

Quickdraw on the other hand, is a play on action economy - potentially killing or defeating an over zealous enemy early.

Level 7 Ability - Aura of High Noon

You have advantage on Wisdom (Perception) checks against enemies within 50 feet of you, and you can also detect Invisible creatures within this aura. If you attack a creature within 50 feet of you before they have taken a turn, you may roll the attack at advantage.

The wording is a bit weird here, and definitely needs work. The intent is better explained in an example; 

Level 15 Ability - Guns Akimbo

Your ammunition is blessed with radiant energy. All your ranged attacks deal an additional 1d4 radiant damage.

Additionally, you ignore the loading property of ranged weapons with which you are proficient. Additionally, you can wield two ranged weapons as long as they do not have the Two-handed property.

For the first portion, we add the Radiant Strikes ability, but for ranged weapons. 1d4 is nothing to scoff at, but after testing, we may consider upping this to d6 or even matching radiant strikes with a d8. The opportunity cost of wielding a ranged weapon first, instead of a melee weapon is quite high. We steal from Crossbow Expert on the second half, but we add the Two-handed property clause here. This means not only can you dual wield pistols and revolvers, but also blowguns, handcrossbows (for the settings with no guns), and slings! This means that you can essentially attack 3 times as well at level 15. 

Level 20 Ability - Peacemaker

As a Bonus Action, you can become the embodiment of peace. 

As a Bonus Action, you gain the abilities below. Once you use this feature, you can't use it again until you finish a Long Rest. You can also restore your use of it by expending a level 5 spell slot (No action required).

Angel of Pacifism. You cannot take the attack action. You gain flying speed equal to double your walking speed.

World Healer. Whenever you cast a healing spell or use your Lay on Hands feature, you may heal the target an additional (Charisma Modifier)d10+20. You must use at least 5 hit points from your Lay on Hands pool to apply this ability.

Subjugate the Scourge. Whenever a creature attacks or casts a spell that negatively affects you or your allies within 60 feet, you may make a ranged attack against them. This does not use up ammunition. This does not require a reaction. Range attacks made this way can be treated as melee weapons for the purpose of Smite spells. 

I KNOW I KNOW. It's kinda funny but also kind appropriate right? I'd give them magical helmets in this form too. Could flavor subjugate the scourge as helmets flying at the enemies too.

Final Smites

Not much to say here. Honestly, I gotta play test the heck out of this, and I have a full campaign ahead of me. Maybe I'll have some updates in a few months or in a year. If you try this one out, do let me know, and feel free to leave a comment!

Who's awesome? You're awesome.

P.S.  Smiteable™ isn't actually trademarked, but it sounds like something that should be.