No effect on accuracy that I've been able to find through research ...

Threading was for BFA....

Swedishicon BFA (Blank Firing Attachment) designed to be used with WOODEN bullets

(Click PIC to Enlarge)


The following pics show ..........

M96 or M38 threaded barrel rifle ............... plastic or metal thread protector ..................... BFA mounted for use

(Click PIC to Enlarge)(Click PIC to Enlarge)


Swedish 6.5 x 55mm m/14 wooden-bullet blanks for use with threaded muzzle BFA (blank firing attachment) and Swedish 6.5 x 55mm m/12 Kammarpatron (gallery cartridges) for indoor training use at 15 meters. Harmless beyond 200 meters.

(Click PIC to Enlarge)

Swedish Service Ammunition (lots more detailed pics ... click here)


Regards,
Badger