Portland stoner/doom metal band Mammoth Salmon will headline a Bend PyratePunx showcase at Di Pizza in Redmond on Friday. (Submitted photo)

Drumming helped Mammoth Salmon’s Chad Walter survive in Iraq.

The U.S. Army veteran served from 2001 to 2007, including a year stationed in Baghdad. Early in his deployment, he received an invitation from his battalion’s chaplain to play in the worship band after the patrol base received a full drum kit.

“He approached me and said, ‘Hey, Walter, I hear you’re a drummer. I don’t know where you stand with God, but if you want to come and jam with us for our worship services on Sundays, we’ll give you exclusive use of the drums and they’ll kind of be your deal that you can play at your own leisure when you’ve got time,’” Walter said recently from Mammoth Salmon’s home base in Portland. The stoner/doom metal band returns to Central Oregon for a show with Bend PyratePunx at Di Pizza in Redmond on Friday.

“So that’s what I did — I filled in for the worship band on Sundays when I could … and jammed with some guys over there. So I was able to at least have somewhat of a musical outlet while I was overseas, and yeah, it was awesome. I can’t tell you how lucky I am to have had that opportunity, because it was a pretty harrowing experience obviously, so having an outlet like that was a huge blessing.”

Since June 2015, Walter has been playing some much different tunes with Mammoth Salmon, which is gearing up for another busy year of touring behind its full-length debut album, “Last Vestige of Humanity” (also released in 2015). Besides the worship band in Baghdad, Walter has stretched out musically before: He said he spent some time in an eight-piece soul band but for the most part comes from a hardcore punk background.

In that way he fits in with his fellow bandmates, bassist Matt Howl and guitarist/vocalist/founder Paul Dudziak, also punk veterans. Despite Mammoth Salmon’s crawling tempos and bottomless sludge riffs, a manic punk spirit still finds its way into the band’s progressions and especially Dudziak’s scathing, socially conscious lyrics.

“This feels more natural to me and where we’re all at right now in our lives, and since we’re all kind of learning together, it’s exciting and it’s not necessarily a challenge as much as some of the other stuff has been,” Walter said. “For me specifically as a drummer, maintaining a tempo is always a challenge and always a part of it. But specifically when (the music is) slower like this, it’s more dramatic, there’s more emotion involved. It’s just heavier. It invokes more inside me than blasting through songs and just going crazy.”

Philadelphia native Dudziak is the band’s only remaining original member. He attended Humboldt State University in California before relocating to Portland and founding Mammoth Salmon with drummer Mitch Meidinger in 2012. This lineup self-released three EPs with Dudziak handling bass (all the band’s albums are available for free at mammothsalmon.bandcamp.com).

By the time the band recorded “Last Vestige of Humanity,” its first release on Devil’s Child Records, the lineup featured bassist Alex Bateman and drummer Steve Lyons. But both musicians were essentially fill-ins to help record the album and were unable to tour, Walter said.

“This is the first lineup that is ready to hit the road as much as possible,” he said.

After his time in the Army was up, Walter relocated to Corvallis, then Southern Oregon, where he played with the band The Hollowbodies. He performed for a time with Galatea when he moved to Portland. A mutual friend — Joey DeMartini of the Portland band Disenchanter — tipped Walter off that Dudziak was looking for a new drummer, but Walter and Howl were already fans.

“It was really interesting timing because I had knee surgery right after I joined the band, so I had to take six weeks off before we could play,” Walter said. “… Fortunately we were able to just listen to (‘Last Vestige of Humanity’) over and over and over again, and get it down and get it solid. That November (2015) was our first show with the lineup that we’ve got now.”

An Army brat as a kid as well as a veteran, Walter was able to bring a sense of discipline to the band’s business dealings. And playing has continued to help Walter adjust to civilian life.

“When I talk about transitioning into being a civilian … it’s just a matter of relearning how to communicate with people, dealing with different kinds of scheduling and stuff like that, and just dealing, honestly, with civilians who have kind of a different approach to how to deal with things, which is really important that we all have different ideas in how we approach stuff,” Walter said. “But that discipline aspect is pretty awesome. It helps with how we load our gear; it helps with my maintenance of our gear, and making sure that I’m not flaking and making sure that we’re on time. I handle most of the driving and the logistics as far as that goes.”

For the past year, the trio has been writing and recording the follow-up to “Last Vestige of Humanity.” Walter said the whole band is now involved in the composition process, whereas Dudziak took the lead on early recordings.

“For me, personally, I think (the songs are) a little bit more complex; for me the structures and changes in some of the songs are a little bit more complicated,” Walter said. “We really kind of, I think, personally, explored using more space. I mean, sometimes other people have already said it better than you can, and Miles Davis said that it’s not always the notes you play, it’s the notes that you don’t play that impact you.”

“So that’s what I did — I filled in for the worship band on Sundays when I could … and jammed with some guys over there. So I was able to at least have somewhat of a musical outlet while I was overseas, and yeah, it was awesome.”— Chad Walter, member of Mammoth Salmon

What: Mammoth Salmon, with Solo Viaje, Zarlock and the Spacemen

When: 9 p.m. Friday

Where: Di Pizza, 3853 SW 21st St., Redmond

Cost: $8 (includes two slices of pizza)

Contact: bit.ly/bbmammothsalmon or 541-527-1242