They're available Tefal, you just have to have valid reason to use them. Main reasons are heavy pigeon shooting or Practical Shotgun, those are the only reasons I know of for their use. Personally I prefer the simplicity of non-fed shotguns.
I had to be a member of the UKPSA and have completed and passed the Practical Shotgun safety course before I'd get the section 1 shotguns.
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(joke)
