if you are only getting 4-6 loading on your norma brass it is not your brass it is you and only you .
what is your chamber ? stock ? custom ?
i have norma brass i still use from day 1 when i had a custom chamber in 6.5-284 done like 12 yrs ago. i do NOT full length size at all. i only size my neck and after only sizing the neck i get 3-5 loadings on that case before i need to give the shoulder a very light pump back .
after you get your loading skills down a bit more you should see your brass start to last a lot more then 4-6 loading .
the only thing i find on my brass after so many yrs of loading is i will start to see a donut at the bottom of the neck on the inside