Police have invited people to surrender unwanted firearms or ammunition so they can be disposed of safely.
New legislation has increased the maximum jail term for illegal gun possession from 10 years to life.
This now includes anyone who is storing a weapon for someone else. It also includes antique firearms.
Police believe many gun owners may not realise the weapons they have could be illegal or the danger they pose if they fall into the wrong hands.
From November 10 - 21, those surrendering firearms will not be prosecuted for offences of possessing them illegally. However, each weapon may be analysed to determine if it has been used in crime and, if it has, it will be investigated.
Chief Superintendent Paul Morrison said: “We do all we can to ensure that firearms do not fall into the hands of criminals and the public can help us. This is why we are giving this opportunity for people to dispose of unwanted guns safely.
“People may have firearms or ammunition that belong to other people, who have inherited them or who might have items they have overlooked or forgotten.
“We would encourage people to check their attics, sheds and cupboards and hand weapons in.
“A firearm might not be a danger in your hands but if it was stolen by a burglar and passed to other criminals it could put people’s lives in danger.
“You can help us by getting rid of any firearms or ammunition you have that you don’t need, both live and deactivated.”
For more information about firearms and ammunition, including when and where you can hand them in, visit www.sussex.police.uk/help-centre/ask-us/explosives,-firearms,-knives-and-other-weapons/what-is-a-gun-surrender