This has already been the case for MANY years, so long in fact that an entire industry have been created to supply a market with large bore versions of AK's and other weapons classed as smoothbore shotguns because only the last few inches of the barrel is rifled.

https://www.thefirearmblog.com/blog/2015/08/13/the-new-russian-shotgun-round-366-tkm-for-sks-ak-rifles/

https://www.thefirearmblog.com/blog/2018/08/30/kalashnikov-concenrns-tg3-svd-chambered-in-9-6x53mm-lancaster/

This has already been the case for MANY years, so long in fact that an entire industry have been created to supply a market with large bore versions of AK's and other weapons classed as smoothbore shotguns because on the last few inches of the barrel is rifled.

https://www.thefirearmblog.com/blog/2015/08/13/the-new-russian-shotgun-round-366-tkm-for-sks-ak-rifles/

https://www.thefirearmblog.com/blog/2018/08/30/kalashnikov-concenrns-tg3-svd-chambered-in-9-6x53mm-lancaster/

This has already been the case for MANY years, so long in fact that an entire industry have been created to supply a market with large bore versions of AK's and other weapons classed as smoothbore shotguns because on the last few inches of the barrel is rifled.

https://www.thefirearmblog.com/blog/2018/08/30/kalashnikov-concenrns-tg3-svd-chambered-in-9-6x53mm-lancaster/

https://www.thefirearmblog.com/blog/?s=366+tkm