Hundreds of guns were seized and dozens of people arrested in week-long crackdown on illegal firearms in New South Wales.

Police executed 20 warrants between October 13 and October 19 around the state.

In total, 45 people were arrested, 206 charges laid, and 270 guns seized.

Hundreds of guns have been seized in raids across NSW during a major crackdown. (NSW Police)

Police also collected 89 gun parts, 19 imitation guns, 10 home-made or 3D-printed guns and 130 home-made or 3D-printed gun parts.

The home-made firearms were a major focus of the operation, and were involved in some of the biggest busts.

Just before 7am on Monday, October 13, police carried out a search warrant in Hinchinbrook, Sydney, where they allegedly found a 3D printer attempting to print a gun part.

Home-made and 3D-printed guns have become a major concern. (NSW Police)

Officers also allegedly seized numerous other firearm parts, electronics, and crypto-currency wallets.

A 41-year-old man was arrested at the scene and charged with multiple firearm-related offences.

The next day, on Tuesday, October 14, in a search warrant in Gosford north of Sydney, police seized another 3D printer and three home-made Glock-style pistols, magazines, holsters, and other items.

Dozens of people have been charged. (NSW Police)The crackdown took place last week. (NSW Police)

A 52-year-old man was arrested and charged with 14 gun-related offences.

Detective Superintendent John Watson said criminals were innovating, but so were police.

“Privately manufactured firearms present a fast-evolving challenge, but this operation shows what’s possible when agencies collaborate effectively,” he said.

“These 3D printed components may look colourful, but they are not toys. Once assembled, they become lethal weapons – entirely illicit and extremely dangerous. That’s why we’re targeting the full supply chain, from printers to imported parts.

“These practices are unsafe, unlawful, and they erode the integrity of our licensing framework; we will continue to act decisively to stop them.”