If you take that route and battle the Vipers at Bonnie Springs, you can get Love and Hate (unique spiked knuckles) and a Trail Carbine.
That may not be a wise move at low levels, as the Leader who has it is always in Combat Armor and odds are good you have nothing that will penetrate it that early on. If you do have some AP rounds it might be doable, though.
For more free swag:
Sniper Rifle on the top bunk in the 1st Recon tent in Camp McCarran- can just walk in and take it
Hunting Shotgun in Charleston Cave North of Jacobstown. NOTE: this is only free if either 1) you have Animal Friend rank 1 or 2) go there prior to starting Guess who I Saw Today, as otherwise there are 9 hostile Nightstalkers there who will shred low-level characters. If the former method is used, you also get Oh, Baby! (unique Super Sledge) for free as it only spawns if the Nightstalkers do. You will need either 75 lockpick or 55/65 with a magazine to get the shotgun, though.
You can get a number of decent early weapons from a locked locker in Jean Sky Diving just outside Goodsprings. The key is on the desk, or you can try to pick the Average lock if you can get your skill high enough. Contents are random, but you can get a SMG or Laser RCW with a little luck. Ammo for the latter will be limited for a while, though.
If you have the lockpick skill for it, the Gobi Sniper Rifle is in a VH-locked case at the Sniper's Nest in the hills just N of Cottonwood Cove.
If you have the Animal Friend perk, the Ratslayer is free.
Can get a number of good free Explosives weapons (notably Missile Launchers) from the armory at Nellis, however the merchant is usually watching over the stock so you'll need to do the drag-and-swipe trick to avoid getting a face-full of 40mm grenades. If you're the sneaky type you can get the unique grenade rifle Thump-Thump for free while you're there; you'll need to have started the quest Ant Misbehavin' to get into the power plant it's kept in (not that Giant Ants are exactly a challenge...).
Multiple good weapons lying around in the houses at Nipton, although one's guarded by a crazed Mr. Handy and another by traps and 3 Bark Scorpions; of note is an Easy-locked safe with a Grenade Rifle and 6 shells. Another 3 Bark Scorpions guard a Laser Rifle just South of the town.
For the Melee-inclined, the unique cleaver Chopper is lying on the stove in the shack at Wolfhorn Ranch, and the unique fire axe Chop-Chop is in the Fire Station in Camp Searchlight (must be doing a quest there to obtain it, but can be gotten with no combat with some luck and sneaking; bring Rad-X and Rad-Away) not far from there.
There's a free hunting rifle in Vault 11 in the Overseer's office on the wall, although the wildlife there may object to your presence. With a Stealth Boy you can get it without combat; the doorway is booby-trapped, so watch your step. Can get a bunch of ammo for various weapons while there as well with 75 in either Science or Lockpick (55/65 with a magazine) for a door next to the security office, including a rare mini-nuke.
Can get various middle-tier items from a scripted fight between Legion troops and a sizable caravan at the overpass near Wolfhorn Ranch, even at low levels you can score a Metal Armor and various SMGs depending on how the fight turns out. They will not shoot you unless you interfere, so just stand back and let them go at it. Also a good place to stock up on Throwing Spears if the Legion loses. NOTE: weapons and armor on the caravan members are random, so you might get a Metal Armor and a 10mm SMG on one try but only leather armor and pistols on another.
Note that I consider 'free' to mean 'didn't pay or fight for it', if you consider the latter to not apply then those feeling a little ballsy can assault the Gun Runners compound and get some good stuff from the weapons shop. Can also sneak in for it, although that's a bit difficult at low levels. There will always be an Assault Carbine and a Plasma Rifle on the tables, plus anything you loot off dead Gun Runners. Note that the Vendortron does not care in the slightest that you just sacked his factory, and will keep selling to you after you trash the place. Isaac may be pissed though, and you need him alive if you're bothering with Conteras' quest; conveniently, the Vendortron sells 12ga beanbag rounds and the guns to use them with, which you can buy with the stuff you just looted off Isaac's buddies. If you do decide to attack the place: the guards wear Combat Armor and carry auto-rifles, so bring a goodly allotment of AP or Hand-Load rounds and healing items.
