Film Comment named the 'Pub Brawl' scene as one of the best fight scenes of the decade.
There is a poster in the Horse and Jockey pub at the beginning of the film which reads Satanic Mechanix, which is the band which Scott Adkins' character killed in Accident Man (2018), the previous film between Scott Adkins and director Jesse V. Johnson.
The German ratings board FSK rejected three different versions of the film (for glorification of violence). Only after an appeal, the third version (which misses 73 seconds) was rated "Not under 18".
Producers wanted to cut a day or so from the shooting of the big end fight sequence, Scott Adkins said "and I don't mind saying that I flipped my lid and had a bit of a screaming match because I didn't want to shortchange the audience" so the producers let them keep the full two days.
At 12 mins.) The leg wound (courtesy of a blast from Cain's sawed-off shotgun) wasn't coming together visually so director Jesse V. Johnson sent someone to a local butcher shop for fresh meat. They stabbed it with a pen knife and dressed it with fake blood. Scott Adkins' father was a butcher so he's seen some sick stuff.