How many of you guys use mag primers & why? I used to use them with all ball powders as it was recommended. Later checking velocities, pressure signs, accuracy etc. I quit using them except large cacity (overbore) calibers with ball powders. Just wondering what the current consensus is?

I use what the manuals state. Standard in some and magnum in others. I figure the Sierra test lab knows more than I do.

quote:

Originally posted by Dwight:
I use what the manuals state. Standard in some and magnum in others. I figure the Sierra test lab knows more than I do.

That's what I used to do as well, but ran out of mags once & loaded a bunch of ball powder loads that performed exactly as the mag primed ones had. so I just quit using them altogether. I don't load any of the overbore mag cases anymore & was just wondering what the other folks use.

Magnum Primers produce a hotter ignition and are preferred in very cold environments such as -20 or colder shooting. I dont shoot in those conditions but I do use Magnum primers for large capacity cases when using a slow to medium powder to ensure good ignition. Example: 81gns H-4350.

Dwight is right on the money.

I've switched to magnum primers with most of my ball powder loads. With standard primers I was getting hang fires with wc846 in 7.5x55 and 30-06. On sunday, I had hang hires with W760 in my 30-06, also with standard primers.

i use std. primers and mag primers. it just depends on the load. i do use mag primers with w748 as it is a ball powder. with imr4064 depending on the cliber, i use std and mag primers. mag primers ignite better but they also raise chamber pressure due to more heat. in colder weather, higher humidity the mag primers will ignite better. i have chronied the diffs. it just depends on the situation for which one i use. just my opinion though. dave

A good rule of thumb is that magnum primers are best when: compressed loads of slow-burning powders (slower than 4350 burn rate) are used; cases are large in capacity (above 55 grains) and of small or medium bore; and where ball powders are used. This, of course, assumes all loads were worked up with said primers from the get go.
For example let's pick on 30 calibre 180 grain bullets in the -06 and 300s. One may or may not use magnum primers in the -06, but should in the 300 Winchester and Weatherby rounds. Why? Case capacity.
Not perfect, but it is a good rule of thumb that has kept me in the hunt without issue.

quote:

Originally posted by doccash:
Dwight is right on the money.

I agree & that's a good policy, but manuals don't always agree. One may call for mag primers for a given load and the next may not
I was mainly wondering if anyone had chronoed the variation with given loads where the only difference was primer type and if you found a diffence. That or noticed a difference in performance as a result of primer type.
Seems there is also a difference between the sme type in terms of "power".
I appreciate the input & opinions here.
I've always wondered why people used mag primers in some (non mag type) loads when my bench rest friends wanted "cooler" ignition for theirs ).
Probably haven't needed the mags here in FL, and because I don't shoot high capacity calibers anymore, but I do like ball powders because they go through the measure so nice & don't take up so much room in the case.

You're never too old to learn. I always thought pistol primers were made with thinner cups due to the lighter hammer falls in most pistols than rifles. I found this week they're all the same thickness
"You live & learn... then you die & forget it all"