The NSW Firearms Registry, a part of the NSW Police Force that manages licences, has said in response that its turnaround times are improving and it must take care when regulating access to guns and ammunition.

Adelong Newsagency owner and ammunition dealer Sean Ryan has been left in legal limbo for weeks as his wholesale suppliers have refused to do business with him until his licence to sell ammunition was fully renewed.

"It is costing me a bit because I have people who ordered things in and I can't get it for them," he said.

"I have run out of a few things and I can't restock them.

"Farmers run into the same problems when they go to renew their licences."

Mr Ryan said he was only granted a notice that he will have his licence renewed last week after starting the renewal process in early April.

"I actually got contacted by phone to say we could [sell ammunition] but I didn't have anything in writing and their system wasn't showing I had the authority to continue," he said.

"The same thing happens to customers' licences as they are processing the applications in the order that they receive them ... our turnaround time is going on 10 or 11 weeks."

A NSW police spokesperson said the Firearms Registry "regularly considers business processes and system improvements to enhance service delivery" and was transitioning more of its paperwork to digital systems.

"For new licence applications, we are seeing a positive downward trend in processing times since the beginning of the year from 130 days to 96 days," the spokesperson said.

"For renewal licences, our average processing times are approximately five days.

"Given the importance of ensuring only the right people have access to firearms, the NSW Firearms Registry invests significant effort into vetting entrants into the firearms licensing scheme by reviewing holdings from multiple sources.

"Also, further information may sometimes be sought from the applicant, such as a medical clearance or evidentiary documentation relating to their genuine reason for firearm ownership. Circumstances such as these can sometimes prolong the processing of an application."

Wagga's postcode has one of the highest levels of firearms ownership in NSW, with more than 2860 licence holders collectively owning a total of 11,121 guns.

Mr Ryan said he doubted that the coronavirus pandemic was responsible for the delays as police officers from Wagga had been able to physically inspect his shop and secure storage soon after he applied for a renewal.

"The police came out and checked the safekeeping and all the records, no worries at all," he said.

"It's just in the actual processing in the renewals and the application for new licences.

"Anything that involves the registry has a very slow turnaround. I think they are just under-resourced."