Para darme de balazos
 

Hi,

Tengo mi par de pistolas,
con sus cachas de marfil,
para darme de balazos
con los del ferrocarril.

I have a pair of pistols
with an ivory head
to defend myself, if necessary,
against those of the railway.

Para darme de comer means to feed me, which makes sense grammatically, too. Food goes from there to here. Para darme de balazos: bullets go from there to here, to shoot me. Really? In this particular context it's the other way around, obviously. How is this possible?

By the way, what is the place of those del ferrocarril? Who are they? La rielera is not going to shoot it out with el conductor y los garroteros, or is she?

My last question: what railroad profession is garrotero?

Here, the pronominal form is to express that it's a reciprocal activity. I will shoot, but I know they will too and the speaker is making sure you know he's not afraid of receiving some shots himself. :)

I will let someone else check on this, but to me, the "I" in the song changes from stanza to stanza. First, is the rielera speaking, then it's Juan.
Juan is the guy with the guns, ready to use them if he gets into a fight with the others in railroad related jobs (that's how he brave is!).
He talks about having bullets for his sweetheart and the guy she may cheat on him with. And at the end we know he's a rielero as well.

"Garrotero" is a helper in the locomotive. They pulled the brakes (garrote) and they still perform other activities the train driver (maquinista) orders.

It sounds like a "garrotero" (or a "guardafrenos") is what US railroad companies call a "brakeman". Originally brakemen controlled the brakes on the individual cars of the train, but modern trains have brake systems that are controlled by the driver, so brakemen now have other responsibilities either on a train or in a train yard. In the US the common name for the driver/operator of a train locomotive/engine is "engineer", although there are several other possible names, including train driver.

@Wrholt: Oh yes, that's what the definition of "garrotero" said in the Diccionario del español de México. :)
Thanks for providing the name for the train operator; I wasn't sure, because "maquinista" and "machinist" don't have the same meanings. :D

And now I've learned another set partial synonyms between English and Spanish: "maquinista" has a broader range of meanings in Spanish than "machinist" has in English. In English a "machinist" is a person trained in the industrial art called "machining" (mecanizado).

Indeed, in Spanish, "maquinista" is almost any person who operates a machine. And I guess we call "máquina" almost any arctifact. ;)
When I was young, even computers or calculators were called "máquinas" by some of my elders. :D

By the way, even the RAE dictionary has nothing to say about garrote as a brake, or garrotero as a brakeman. Although the words, in the railroad context, are suggestive to the point of obviousness.

The printed Gran Diccionario Español-Ruso has :D

Figurative senses of many words are not always included in all dictionaries. :)
"Garrote" must have been used to picture the shape and size of old locomotive brake levers.
There are many words that either were born or are used in a certain way by the population of some region; that is why there are 23 "Academias de la lengua española".
We normally use the Spanish one as a common reference, because generally we understand each other in a standard register and use of language. For exceptions and local variations, most of us have our own references, like the one I quoted above. ;)

Glad you have a good dictionary for reference. That's very important for learning a foreign language. :D