Any tips on taking down the BoS with a Trail Carbine, Cowboy Repeater, Mysterious Magnum, and .357 Revolver?

Bring lots of stimpacks.
Get the Cowboy Perk to deal additional damage with Dynamites and the Cowboy repeater.
Get the Fast Reload Perk to shoot faster with the Cowboy Repeater.
Get the mods for the Cowboy Repeater, notably the one that makes shooting faster and the one to get the gun to hold more bullets.

The result is that with the Fast Reload Perk and the mods, the cowboy repeater becomes a semi-automatic weapon that destroys anything in its sight.
With a high explosives skill and the Cowboy perk, Dynamites deal a lot more damage than grenades.

...And aim for the head!

I did the whole game with only cowboy-related equipment and the sheriff duster. Some parts were difficult, notably the BOS bunker, but lots of stimpacks helped there.

http://i72.photobucket.com/albums/i185/DarkBrotherhoodmod/Sheriff.jpg

that guys bada** i wish my character was as cool as that

Keep shooting. Use cover , move to other cover. Use stims and drugs while behind cover if they start slapping you, use vats....

Thanks guys... there aren't any ammo types that will help right?

Taking on BoS Paladins as a Cowboy after the last patch is going to be pretty damn challenging because Cowboy guns have been made much slower than they used to be.

Here's what you need:

1) Brush Gun or Ranger Sequoia or Hunting Revolver; BoS Paladins have monstrous DT, and you need high DAM to mitigate it.

2) Highest DT armor you can find EXCEPT Metal Armor or T45d Power Armor. You don't want to lower your Agility even by a single point.

3) Lots of Stimpacks. Hotkey them for use in a hurry.

4) Drugs wise, bring the following: Slasher, Med-X, Steady, Jet, Dixon's Jet, Rocket (DO NOT use Ultrajet, its addiction is permanent and cannot be cured by doctors), Buffout. If your Agility is 6 or lower, bring Fire Ant Nectar as well. This combination will give you +50% damage resistance, + 25% damage, +60 hitpoints, vastly increased accuracy and a huge amount of action points for V.A.T.S if you use it.

Your companion must wear highest DT armor you can give them and either a Pulse Gun or one of the high-damage weapons which ignore DT (Chainsaw or Thermic Lance). I would suggest one of the following combinations:

Arcade+ Pulse Gun

Veronica+ Pulse Gun (set her to ranged

Lilly+ Chainsaw or Thermic Lance

Boone+ Chainsaw or Thermic Lance (set to melee).

Cass+ Riot Shotgun + lots of 12 gaugef slugs ammo.

If you have some of the ammo mod yes,(Steel cap and DU-S rounds help here.)

http://www.newvegasnexus.com/downloads/file.php?id=37653 <

With Cowboy weapons? Go with the specialised ammunition you get with the Handloader perk. .357 JFP has a minor DT modifier. .44 SWC has a bigger one. .45-70 SWC also helps. In a pinch, especially now that it's patched, use That Gun (a revolver, and under the influence of the Cowboy Perk) with AP rounds. That should tear them up something fierce.

maybe some of those handloader rounds. I never got into them so I m not sure what weapons you can use then for, but don t use hollow point on bos.

post patch use a chainsaw it ignores dt now making it a beast against heavily armored foes chainsaws are kinda cowboy right? I never had trouble with the brush gune before it was ridiculously easy so it might be harder but should still be do able with some tactics ie using cover also medx, pyscho, and slasher would be a wise idea nothing beats a 50% increase in damage dealt and 50% decrease in damage taken.

Looks like im going to try to get a Riot Shotgun, Brush Gun and Ranger Sequoia.

I only see a bunker with deadbodies with this much firepower.

Go to Vault 34. Get pulse gun. Laugh at those T-51b wearing wimps. Even with a zero EW skill it's a two shot kill against all power armored BoS troops.

Now if your character is some sort of zealot that would rather die than use an energy weapon. Brush Gun with SWC rounds applied to the head.