The question misstates the claims of the articles in a seemingly slight manner, but it greatly affects how we would answer the question.
Neither article specifically claims that "hammers" (a very specific kind of weapon) kill more people than "guns" (a catch-all for all types of firearms). They both claim that "blunt objects" kill more than "rifles."
The nola.com headline does claim that "hammers" kill more people than "rifles", but in the body of the article, it is made clear that the author is referring to "blunt objects (hammers would be in that group)". Since the nola.com article refers specifically to the 2012 homicide data, you can see that the number of people killed that year by rifles is 298 versus 522 for blunt objects. If you assume that the rate of "rifles" within the "Firearms, type not stated" category is about 4%, consistent with ("rifles")/("firearms" - "firearms, type not stated"), you can extrapolate about 371 total murders with rifles, still significantly less than the 522 attributed to blunt objects for 2012.
The gunssavelives.net article never claims to be talking specifically about "hammers" in a specific sense nor about "guns" in a general sense, it is very clear throughout that the author is talking about the category of blunt objects ("Hammers, Clubs & Bats") versus the category of "rifles". The gunssavelives article does not cite a specific year, however it was written in early 2013, so it is possible they were looking at 2012 data.
The claim wrongfully attributed to both articles, that "hammers" specifically kill more than "guns" generally, is false.
However, the actual claim in both articles is true, although the headline of the nola.com article is either somewhat misleading, if the author genuinely thinks that the reader will understand that "hammer" is standing in for a larger category, or false if not.
If you look at the most recent data from 2016, and extrapolate the number of rifle killings within the "firearms, type not stated" category as I did with the 2012 data above the number of people killed by rifles is more than those killed by blunt objects, (about 519 killed by rifle versus 472 killed by blunt objects), but both articles are correct for the year that they claim or the year they were written in.