Upon its release, the album was met with generally favorable reviews from music critics. Amanda Bassa of HipHopDX wrote, "Low points will be hard to find on Double Barrel, and the project offers up something for those craving the boom bap as well as something that feels relevant in the present." Addi "Mindbender" Stewart of KevinNottingham.com felt that "conceptually and ultimately, not much new ground is broken here. But alternately, and equally importantly, [Marco Polo & Torae] carry on certain hip hop traditions faithfully, yet in their own signature way". The reviewer claimed that the album would "essentially be thought of at as one of the more satisfying offerings of east coast rap music in 2009." Pedro "DJ Complejo" Hernandez, writing for RapReviews.com, remarked that Double Barrel is a "banging album full of unadulterated hip-hop." He believed that "Marco Polo should surely become a hot commodity with his brand of head banging boom bap beats." He also complimented Torae as "a solid emcee" because of his ability to tell stories, his "brash" braggadocio, and his passion which "matches that of the best emcees". Additionally, he mentioned that the Brooklyn rapper can really showcase his talent when he has "the right production behind him". Similarly, Sobhi Youssef of Sputnikmusic wrote, "The production team excels largely in providing an acceptable sonic backdrop for Torae to rhyme over". However, he opined that "without this (or even DJ Revolution's tasteful cuts on a few joints), he is nearly indistinguishable from other hardcore bent tri-state rappers." He then asserted that "this happens with startling (but welcome) frequency as Rocc [sic], Guilty Simpson, Masta Ace, and Sean Price steal the spotlight for their respective featured verses, adding a lot to the track."
In his mixed review for The Smoking Section, TS obversed the record's drawback is "the basic business model of things", explaining, "Torae spends the majority of the LP denouncing industry politics while Marco Polo's production tends to blend together with seemingly the same bassline and song tempos by the album's midway point."XXL reviewer Jonathan Bonanno noted that in spite of "lackluster records" such as "Word Play" and "Party Crashers", Double Barrel is in overall "a solid offering" and claimed that "Marco Polo & Torae's potential as a formidable producer/ MC team is without question—even if they never get the mass appeal."