Mag Primers vs non-mag Primers

[atr]

Ive never used Mag Primers in my large rifle reduced loads (.308, 30-06, .303 etc)
and I am wonder if using Mag Primers would perhaps give better ignition to reduced powder charges,,,for example 14gr of Unique in a large capacity case without a dacron filler....
any comments would be helpful
thanks
art

[DanM]

My experience has been that Mag primers do not help much with fast powders in rifle cases. You may even loose a little accuracy with mag primers and small charges of fast powder. OTOH, with slow powders and filler, they help a lot. YMMV

[Boerrancher]

I keep a few mag primers on hand for my mag rifles. I live by the rule that if you are burning over 60 grs of smokeless powder then you need a Mag Primer. Esp those ball powders that have a heavy graphite coating. This rule does not apply to the Holy Black. Also like most rules I do break that one depending on what I am doing. In the summer time I do not use mag primers in my 300 win mag, unless I just want to tighten up the group by a quarter to a half an inch. When I was hunting in the mountains out west, I would use the Mag primers because of the cold. Most of the time though I have found that a Winchester Standard Rifle primer is more than hot enough to ignite 85.5 grs of AA3100.

[Maven]

"...I am wondering if using Mag Primers would perhaps give better ignition to reduced powder charges, for example 14gr of Unique in a large capacity case without a dacron filler...."

atr, Frank Marshall, Jr. of the Cast Bullet Assoc. recommended and used 13grs. of Unique in the .45-70 with CB's, standard LR primers and no dacron tuft. (Talk about a miniscule charge getting lost in a large case!) I've tried it several times and was quite pleased with it: Very accurate, little recoil, economical to shoot.