Hi all,
Am relatively certain the question of why using magnum primers across all powder loads would be a problem. Is there an issue here?
Thanks,
Stephen

I don't understand what you trying to accomplish
As a rule of thumb for rifle you would use a standard primer up to 60grains after that a magnum primer.
There are exception for all of it.. if its 30 below zero I would want a magnum primer. especially with a case full of powder

There is no issue, but...Accuracy will suffer with mag primers in cases that hold less than 60 grains. Also, if you work up loads in cold weather, especially in smaller cases and push max, you may find you have a problem when the weather warms substantially.

The magnum isn't going to be unsafe per se, just different. When I tried it, it was a mixed bag as to which was more accurate or more stable for velocity changes.

If you work up the load using the magnum, I don't think its a big deal, but I know that Ken Waters (of pet loads fame) did note the magnum primers could raise pressures, and also related that too hot a primer increased SD of velocity in small cases.

I haven't really used magnums too much except when the load called for magnum- which is usually over 50 grains of ball powder or over 60 grains period, but the manual tells you which, or if you are having hangfires with a standard primer.

Gentlemen,
Thanks for the comments all of which contributed to my understanding. Follow the book, eh?
Stephen

Magnum primers is recommended for all ball powders as to prevent "double detonation".

Reloader270..


posted 09 April 2020 13:48 Hide Post

Magnum primers is recommended for all ball powders as to prevent "double detonation".

A Winchester WLR primer can handle any ball powder in 30-06 size cases. I have even loaded 7MM rem mag with WLR with stick powder. and a 264 win mag

In most reasonable hunting loads you won't notice any difference. Only on the margins of slow powders, ball powders, or high pressures, will you.

quote:

Originally posted by Reloader270:
Magnum primers is recommended for all ball powders as to prevent "double detonation".

What is "double detonation" and what is the source for the recommendation?

Not sure if it has any credibility. something to "exer size" the mind..
For all the test out there I have not seen any Double detonation>

http://www.accuratereloading.com/primer.html

Maybe "double detonation" is somebody's term for a hang fire ?

My 300 win mag shoots better with standard rifle primers. One reloading manual recommended it. If you go from standard to mag drop a least a grain of powder to start.

quote:

Originally posted by craigster:
Maybe "double detonation" is somebody's term for a hang fire ?

No, a hang fire is different but can indicate an impending situation where detonation occurs.

Low charges of slow burning powder can give hang/delay fires i.e. a noticeable delay when the 'hammer' falls and the shot goes off. Sometimes the delay is a slow click-bang and others a barely perceptible click-bang. I've experienced both at various times when experimenting around with reloading for some cartridges. It is a phenomenon that needs backing off from quickly, hotter primers and or filler helps or going to a faster powder. Magnum primers are recommended for ball powders due to their difficulty in igniting compared with extruded powders.

Detonation, is almost like a reloading myth. Over the years various labs and individuals have tried to induce detonation under controlled and reproducible conditions but have seemingly failed.
Nobody has a definitive answer as to exactly what it is and how it occurs other than just general warnings not to use low charges of slow powder and to use good magnum primers with large charges of slow powder and ball powders.

Detonation seems as though it maybe semi ignition of powder due to primer flash over of low powder charges or harder to ignite ball powders which causes the bullet to move off into the rifling leade as primer or some powder ignition pressure drops off then the main powder charge ignites rapidly building pressure behind what has essentially become a barrel blockage.
There have been instances of actions being wreaked through supposed 'detonation', although not being a controlled experiment, other reloading issues could not be ruled out.

Obviously with delayed or hangfire ignition we cannot see what is happening in the case and to the bullet but it is felt that these conditions are a precursors to detonation.

I haven't heard of the term 'double' detonation but I think what is meant is the the phenomenon I've described above. Usually it is just the term detonation that is used to describe the action wreaking 'explosion'.

In my NORMA loading manual, they use Winchester Magnum primers on all the loads listed.
And NORMA has a reputation being a pretty serious company.
I use magnum primers on my 338-06 A-Square loads as the manual say, and so far so good.

On occasion I'll get a "dud" handload. I break them down to reuse the brass and bullet. I've found what I would call a partial burn of the powder, like a fire started and went out. Primers were standard and the powder IIRC was milsurp 844 or 846 (both ball). I've used a lot of both powders over the years and it doesn't happen all that often. I think it's just a weak primer not igniting the ball powder.

quote:

craigster posted 12 April 2020 06:56
On occasion I'll get a "dud" handload. I break them down to reuse the brass and bullet. I've found what I would call a partial burn of the powder, like a fire started and went out. Primers were standard and the powder IIRC was milsurp 844 or 846 (both ball). I've used a lot of both powders over the years and it doesn't happen all that often. I think it's just a weak primer not igniting the ball powder.

What brand of primer gave weak ignition ?

Been a while back but I think CCI, and only now and then.

In what you would call "accuracy rifles" Fed 210 were best for me for 270, 6mm/06 etc. Fed 215 in 300 Winchester, 338 Winchester, 358 STA. However, 375 H& was the exception and Fed 210 wer best. This was across several rifles and barrels.

Fed 215 in 270, 300 Wby and all the 378 based calibres.

Been a while back but I think CCI, and only now and then.

Funny you should say it possibly happened with CCI Primers.
I had run of dud CCI Primers from a couple of batches some years ago. Luckily I found ouf while range shooting and not hunting but it annoyed me enough I switched to Federal primers anx never looked back. Used multiple thousands of Federal and never a dud.
I'm using up my remaining CCI's from those same batches in strictly practise loads at the range and so far no more duds but I know I will find one or two sooner or later.

quote:

Originally posted by Lord Frith:
Gentlemen,
Thanks for the comments all of which contributed to my understanding. Follow the book, eh?
Stephen

I've wondered about using MPs for everything, too.
Just approach the book maximums cautiously.
I kinda like the idea!
Let us know if you run into anything to share.

An old adage, ball powder over 30 grs, use magnum primers. Below zero weather or over 60 grs. of powder, magnum primers. All other, standard primers.

quote:

An old adage, ball powder over 30 grs, use magnum primers. Below zero weather or over 60 grs. of powder, magnum primers. All other, standard primers.

I have loaded the 270 win. with 53.5 grs of H414 with standard WRL primers, no problems at all