They will unveil new material on Friday at the O2 ABC - having been locked away in a Belgian studio for part of this year.
And the band took full advantage of retro equipment to create the sound they were looking for.
"We were recording at ICP Studios in Belgium, and it has got all the best equipment," says singer Dante Gizzi.
"They have been collecting it since the 1970s, so there is all this great old equipment - keyboards and old Moogs (synthesizers).
"You can't help but want to go and experiment when you see all these things.
"They are nice to layer in certain songs - the songs are quite rocky as it is, but you want to mellow it a wee bit, just as we have become more mellow in our older years."
Gun have not become too mellow, though, and anyone heading to see them at the ABC can expect a typically rowdy night.
Last year's Break The Silence album was the group's first since founding member Dante moved over from bass to take over frontman duties, and he believes they have got stronger since then.
Yet they are also adding some new flavours to the mix - with their next record, currently titled East End and scheduled for release early next year, featuring the band getting brassed off.
"We had Gavin Fitzjohn in, who played in Paolo Nutini's band," says Dante, who lives in the East End of Glasgow.
"I have always loved the use of brass in music, and one of the things ICP Studios gave us was the chance to play as a band and come up with ideas as we went along.
"We already had some rough demos, but with Gavin playing sax we had some great ideas, some great hooks from that, and there are about four or five songs that have brass running through them.
"My mum and my dad were always massive fans of the Big Bands, and that probably came off on me a bit."
Dante is keen to stress the band have focused on melody this time, and have also changed their working habits around. This time they have gone with the flow in the studio more.
"With El Presidente, Dante's old band, which existed when Gun were on hiatus, and with the last Gun album we stuck to what we had already got as the demos," he says.
"I know that I get too wrapped up in the demos and making them the best they can sound, and then there is nowhere to go from there. With this album, I have tried to chill back a bit and rely on the creativity coming from the other guys as well, wherever it takes us.
"We would get a couple of bottles of wine in and just jam into the small hours of the morning. It was great fun."
The band's recent work has also seen a change for Dante himself because he has tried to be less possessive about the group's songs, and let other band members be more involved with the creative side.
He says: "You are really possessive about it, and do not want anything changed.
"If someone comes along and wants to change it, whether another member of the band or a producer, then you think, 'No'. I kind of get possessive like that, although a lot of people would say it is egotistical …"
Ego or not, it has helped the band survive nearly 25 years in the music business. As the band heads towards the quarter century mark next year, Dante feels his passion is as strong as ever.
"This is my one love, my life," he says. "I feel very lucky and very privileged to be able to do this, and what is still there and still very strong is that the hunger to make music is still there.
"I love getting up in the morning and going down to the studio to work on ideas, or work on new songs, then playing new material for people to hear.
"That is a buzz in itself, and I am scared of the day it has to stop."
He is also full of praise for Scotland current crop of bands.
"The band I am following most now are Twin Atlantic, we are friendly with them," he says.
"Frightened Rabbit are really good, we are right into them and I am sorry I have never got to see them at the festivals. It is great to see Scottish bands like that are out there."
n Gun, O2 ABC, Fri, £15, 7pm