The Shotgun is not legal to hunt deer with slug as it does not meet the criteria of the deer act . Not saying it wont do the job , just you cant make it legal in the UK . A 45-70 would be far better and is already legal for the purpose . Of course to end suffering you must do what is reasonable under the circumstances , though getting a shotgun for UK deer is not compliant . A few have been granted pistols for deer tracking purposes on call out situations, that also are not compliant to go out out to hunt deer only a mercy shot for those situations like a vet or a regular tracking team member and only certain constabularies will issue those
