quelques liens
http://norma-6br.ifrance.com/norma-6br/
http://translate.google.com/translate?sourceid=navclient&hl=fr&u=http%3a%2f%2fwww%2eriflebarrels%2ecom%2farticles%2fbullets%5fballastics%2fthroat%5fangles%2ehtm
http://www.6mmbr.com/reloading.html
http://lapetoire.free.fr/pages/Armes_epaule_mod.htm