thoughts on using mag primers in 308

[Willoughby]

an older friend who reloads said he uses mag primers in everything he loads -
this is the second oldtimer to tell me this -
so if more ignition isnt a bad thing then why not ?
they both said work up -stay 1 or 2 away from max
any thoughts guys ?

[darkker]

They are old, luddites:p

EARLY ball powders could be difficult to light if it was extremely cold outside.
I use Win 760(quite old) and 748, and have never had any issues, even up in the snowy-shyte filled peaks of N. Idaho.

I use CCI, or Win primers. I interchange mag & non one my 308, 243, 25-06, 270 with no statistically different velocities.
I don't have a Pressure Trace, but with ZERO difference in Vel, I can't see there being a monsterous pressure difference.

The one diff I DO notice, is that Mag Primers open up my ES.

[Willoughby]

so you ahve actually measured the velocity on same loads with both primers ?
my 308 shoots with same accuracy with both but with mag primers it takes 2 grains less powder to get the accuracy of my 'normal' non mag primer load
175smk 41 Varget with Fed 215's
or 175 smk 43 Varget with Fed 210's
wish I had a Chronograph
but there is a definate difference in grains to get it under .5
same with my 3006
2 grains under
just wanted to hear the pro's &con'

[drybean]

some mag primers only have thicker cups

drybean

[darkker]

so you ahve actually measured the velocity on same loads with both primers ?

175smk 41 Varget with Fed 215's
or 175 smk 43 Varget with Fed 210's



Yes, I measured them. I believe(But am not positive) that the Fed primers are a "Basic" type compound. Whereas the CCI/Win are not. THAT could have something to do with it.

I know the cartridges I listed, with the powders I listed show no difference, OTHER THAN the opening of the ES, in the 308 class case. The '06 based cartridges don't open as significantly.
YMMV,

FWIW. In the 308 I never could get "happy" with Varget and 168-175's, Was to dodgy for me in the heat. I never fooled with the mag primers with that powder.

[earl39]

some mag primers only have thicker cups

drybean

Wolf and Tula primers come to mind on that point.

[MZ5]

This is an instance where I follow the book; I use mag primers in my 308 if/when I'm following my Speer manual's loads (which is much more often than not), because they always use a mag primer with the Ball Powders I prefer.

[darkker]

The KVA primers aren't really any thicker, perhaps "harder" but not thicker. Remember that the Mil-spec sensitivity isn't achieved by thicker cups, rather by anvil height.

Also, Mag primers were specifically built(originally) for Roy Weatherby's 70+ grain cases of ball powder.

Few links you may find interesting.


http://www.noslerreloading.com/phpBB2/viewtopic.php?f=4&t=16357

http://www.jamescalhoon.com/primers_and_pressure.php



(http://www.jamescalhoon.com/primers_and_pressure.php)

[irondog54]

I use mag primers exclusively. FOR ME they are more consistant, and ignite powder more reliably. Groups are smaller for the same loads.