Watching through the Second Season, fast-forwarding to all the instances featuring weapons, a detail spawned a meta-bunny that started nibbling on my brain the further the slippery slope I got.
If there was one thing the First Season brought home to the viewers, weapons-wise, it was that Sam hardly carried around a gun unless they were going in for the kill.
Dean was the "Be Prepared"-guy, the one who handed out weapons and took care of them.
This changed for the Second Season.
To the point of Sam caring for the guns in No Exit (2x06).
The two episodes preceding that, Children Shouldn't Play With Dead Things (2x04) and Simon Said (2x05), established Sam's taste in men guns. We weren't given background on which one of them chose the Taurus Sam plugs Angela with, but in Simon Said (2x05), Sam picks that gun by himself out of the trunk.
This is the reason I fall in love with this series all over again every time I watch the episodes: the details hint at and bolster whatever is going on inside the boys' heads.
During the First Season, Sam is the Tragic Hero who'd rather not be doing what he is. He knows the ropes as well as Dean, he performs as well as Dean, but Dean's the one who's enthusiastic about the hunt.
During the Second Season, Sam accepts his fate, pulls a more reluctant Dean along with him. He's become an active part of what's happening, he's taking control and choosing his own weapons.
Granted, Sam still didn't carry around a gun unless a hunt was on, or he could see trouble on the way. There's nothing to back up the idea he had a gun in Born Under A Bad Sign (2x14) before Dean brought the arsenal with him. Neither did he seem to have armed himself with anything specific in What Is And What Should Never Be (2x20) while facing the Djinn. Or in All Hell Breaks Loose, Part One (2x21).
For a nice juxtaposition, consider the two scenes so far of Sam leaving Dean, the stuff he takes with him, in Scarecrow (1x11) and Hunted (2x10). In the earlier, he's seen grabbing his computer, his backpack and a duffel, walking away. One might hazard a guess that either his backpack or the duffel contained a weapon or two (he was, after all, heading off to California to help John bring down a demon), but nothing in canon hints at that. He also 'borrows' a car to get back to Dean.
In the latter, Sam grabs his computer and his backpack and hijacks a car rather than walking away. He also brought his friend, Taurus, along for the ride as Gordon found out. And that gun is curious indeed. To the point of all this being born mainly out of its appearances.
For Taurus, Model 92? Sam's favoured weapon during the Second Season?
Is the same gun Max Miller blew his own brains out back in Nightmare (1x14).
Is the same gun Andrew 'Andy' Gallagher shot his twin brother dead in Simon Said (2x05).
Is the same gun Sam used to kill Jake Talley in All Hell Breaks Loose, Part 2 (2x22).
An intriguing aspect is also the fact that, far as I know, the boys even have the Taurus anymore. After Max's suicide, one might think the Police would have confiscated the gun. Same goes for Ansem/Weber's 'suicide' weapon.
But then, logic has stepped aside in Supernatural's canon for better storytelling before (remember how well John walked in In My Time of Dying, 2x01?) And it does make a fascinating thought, doesn't it, to realize that all the PsyKids that have died via a gun (that we've seen), have met their maker at the business end of the Taurus?
This also makes Sam's future look possibly a little worrying...
And the gun Dean favours, Colt 1911?
It is beyond any shadow of doubt the gun ratcheting up the body count.
Like the Taurus, it didn't become a brother-specific weapon before the Second Season. Yes, it was seen in action (at least in 1x06 and 1x17), but no more than any other gun.
Then, when the Second Season really started, beginning with Bloodlust (2x03), this gun began popping up rather frequently.
In Bloodlust (2x03), Dean aims it at Gordon.
In Children Shouldn't Play With Dead Things (2x04), Dean makes Angela "rattle like a change purse."
In Simon Said (2x05), Dean keeps it close to himself while trailing Andy.
In Croatoan (2x09), Dean deals with Papa, Beverly and Duane Tanner from behind the Colt. It's also the same handgun he points at Sarge and would with all probability use to euthanize Sam and then himself if things turned out darker.
In Born Under A Bad Sign (2x14), Dean bursts in on Sam and Jo with the Colt 1911 in hand.
In Heart (2x17), Dean has it when he goes to Kurt's apartment, and when he kills Glenn. It's also the Colt that is used to kill Madison.
In All Hell Breaks Loose, Part One (2x21), Dean charges with it into the Sunnyside Diner.
In All Hell Breaks Loose, Part Two (2x22), Dean approaches Jake Talley in the cemetery with it. In the same episode, it's not the Colt 1911, but a very special relative of it that Dean uses to deal the finishing blow to the Big Bad.
Writing this has made me aware of another detail-consistency that I adore; whenever Dean has reportedly used silver bullets (1x06, 2x04, 2x17), they've been loaded into the Colt 1911. As seen in Skin (1x06) and Heart (2x17), the boys have those bullets in two different calibers: .45 and (quite possibly) 9mm.
With the Second Season, Kripke and co. knew where they were standing, who the Winchesters were, how far they could take the show, what depths they could safely brave. How much they could dare to hope for the fans to 'get'. And thus the Second Season is a parade of fan service for the detail-minded. One example of which are the gun-preferences of the boys.
The significance of the guns eludes my grasp, though.
Of course, it's more than likely that this is a classic case of the cigar being just a cigar. But, hey, speculation is fun!
I think it's perfectly possible that Kripke and co. decided to name the Taurus as the PsyKid Killer. Which leads me to wonder if anything else has been killed with it... Sam has pointed and fired the gun in question several times, but never has he managed to bring down anything before Jake.
The Colt 1911's meaning is even murkier. Unless its prominency was foreshadowing for the Season Finale and the return of The Colt and its Magic Bullets. There's a meta about those lurking around in my brain...
In conclusion, Sam likes the Taurus because it's as bullheaded about staying gone as he is, Dean's usage of his prettified Colt heralded him as The Hero and this series has brought out my so-far-dormant fetish for guns.
I would also like to add that I won't be really surprised if Sam'll be more gung-ho during the Third Season, a bit more paranoid, a bit more trigger-happy, a bit more cold-blooded.
And that scares me.
References:
Supernatural, Seasons 1 & 2
Erinrua's Wonderful Weapons Page for Supernatural
Erinrua: Thank You for your (and your understanding husband's) awesome job of compiling the data and helping me to verify the Taurus' presence in 2x22. :)