I am working up loads for a .270 and will try a couple of other powders than my old stanby-IMR4350. When using heavy loads of ball powder (760 in this instance) do any of you use magnum primers? What about with full loads, say 60.0 gr of H4831?

I use 760 in my .375, so of course I use magnum primers there. I use it in 7x57's and have always had good luck with standard primers. But I have read many folks say that magnum primers give better results with ball powders

I use std WLR primers for all my 270 loads, this includes some loads I tried with H1000. H4831, R22, ect, ignite fine as far as in my rifle and I`ve seen no reason for mag primers.

I developed a couple loads with imr 4064 and 140gr btsp for the 270 and used rem 9 1/2M for better ignition.
With mag primers I gained about 25/s
I was looking to get about 2750 out of the load.

No mag primers for me in the 270.

I tryed cci mag per what was printed in a reload manual, working up loads useing h4831 and got big 'ol extractor slot marks on my brass and hard bolt lift.

I've been useing standard WW primers with my h4831 .270 loads

For my .270 Win., I use plain old Federal GM-210 match primers. My load is 57 grs. of Rldr-22 with a 150 gr. bullet. Years ago, when I used H-4831, I tried mag primers but don't think I needed them then either. Suppose I could try some magnum primers. Maybe accuracy would improve some but I dunno.
Bear in Fairbanks

I use IMR-4350 as a definitive line between std and mag primers. For IMR-4350 and faster burning powders I use std primers. Anything slower than IMR-4350 I use mag primers. In extreme cold (<15°F) I might consider mag primers.