Heya,
I'm looking for some Feedback from you guys what you think would be the best weapon for Boon. So far I ruled out any Shotgun, Assault Rifle or SMG since I usually engage combat from a huge distance and he would be firing tons of ammo hitting nothing. So I'm looking for a weapon with a very high damage per hit, high DPS and good precision. Preferably not too expensive ammo and prefably not sharing the ammo types I use (Brush Gun and Silenced Sniper Rifle)

So I narrowed it down to:

http://fallout.wikia.com/wiki/Brush_gun
http://fallout.wikia.com/wiki/Trail_Carbine
http://fallout.wikia.com/wiki/Gobi_Campaign_Scout_Rifle
http://fallout.wikia.com/wiki/Anti-Materiel_rifle
http://fallout.wikia.com/wiki/Sniper_rifle_%28Fallout:_New_Vegas%29

or (Energy Weapon)

http://fallout.wikia.com/wiki/YCS/186_Gauss_rifle

With only the Anti-Materiel Rifle being already in my possession - and from what I can see seemingly very low DPS. Any thoughts?

Companions don't use up ammo.

Sniper Rifle or Anti-Materiel. Gobi Rifle would be good, too.

Thought they only not use ammo for their default weapon...

Maybe you're right. Boone grabbed a 9mm SMG from the ground and stop using his rifle entirely for a while until I took the dang thing away from him. I don't recall him having any 9mm ammo to use with it.

I might have to do some SCIENCE on this topic.

He done that to me as well when I killed the kings he pick up a smg so I think if they pick them up they don't use ammo but if you give them it it needs ammo

Companions have infinite ammo for their default weapon, others you provide - you must also continue to provide ammo as well.
Boone will yell out during a gunfight that he's low on/about to run out of ammunition. It pays to check his inventory when things are quiet, and keep a good eye on the contents.
I've found (after parting with 7,000+ caps :facepalm: ) that Boone won't equip the anti-materiel rifle for some strange reason.
Maybe others have had better luck.

Short answer: he's a 1st Recon sniper, an excellent shot. Give him some type of sniper rifle, modded or otherwise.

I have Boone using the Gobi Sniper Rifle and he seems to be quite good. I tried giving him a higher DPS gun like the Marksman Carbine or the Trail Carbine but he just didn't seem as effective. I think the Gobi rifle is the best bet. As for the ammo thing, I always have to keep refilling him.

As an aside, one of the main reasons I didn't give him the Trail Carbine or the Brush Gun is because I just couldn't find enough ammo to keep him stocked. That .45-70 Gov't ammo (and .44 ammo to a lesser extent) was a pain to find, and I really didn't want to share it.

Let him use his default weapon. He's a beast with that hunting rifle, and if it aint broke, don't fix it!

This is what I ended up doing, just seemed most simple and straightforward,

I've had him pick up 12.7mm smgs and marksmen carbines among other things and use them without ammo.

Maybe it has to do with his Level. The gun requires 100 Skill - he will equip it for me (L20).

Boone most definitely uses up ammo in my game. Could be due to the fact that I GAVE him the weapons as opposed to him just picking it up, he's picked up a few things here and there and I always took it back, guess I should have let him have it.

I wonder if he'd pick up something you dropped on the ground, that way you wouldn't need to give him ammo, that way. Hehe

Heh may have to try that with the brush gun

Remember too that Boone is just as good with melee weapons as he is with guns (both skills are at the same level), so you could also give him a super sledge and he'll own faces with it. I actually have him using the unique disrupter glove atm ("Pushy"), and even though he doesn't have unarmed as a skill, he still kicks serious [censored] with it. He kills things with it just as fast as Veroinica, who actually has unarmed as a skill.
Hell, anyone can kick [censored] with Pushy. I had Arcade using it for a while, and he was awesome with it.