Powder choice and magnum LR primers

[jacobhh]

I've been trying to figure out when to use magnum primers
for a while and remain thoroughly confused.

The rules and opinions seem to be all over the place, the load
data books disagree. For example 150 gr. Speer and Sierra in
30 06 Springfield, AA2460 powder. They use very similar test
rifles and their bullet offerings are similar. Sierra doesn't ever
seem to like magnum primers so they don't spec them. Speer
specs magnum and a bit more powder for the same velocity??
The powder is not particularly 'slow', the charge is not large for
a 30 06 case and it's not a magnum load so there go those
guidelines.

I've taken to assuming that if Speer specs a magnum primer,
I've made the wrong powder choice for that cal./bullet. Is that
reasonable? I hate to waste powder through ignorance. Do any
of you folks have experience tested opinions on when to use
magnum primers with, say, BL-(C)2, which I have a can of and
don't use because of the above? I just used 30 06 as an example.
I reload for half a dozen calibers and haven't any idea as to
when I should use a magnum primer. Are there hard fast reasons
or is it all preference and nebulous opinion?

 

[Bad Flynch]

Well, look at the corporate affiliations of Speer. Speer is part of the conglomerate that also owns CCI. Now, CCI regular primers are fairly mild. One might expect that Speer is going to use mostly CCI primers in developing its reloading data and hence, will probably recommend the use of CCI magnum primers on ball powders and other hard-to light numbers.

However, one could look at Winchester data, and others who use W-W primers. W-W has made their regular primers hotter than normal for a long, long time. That, because they were made to ignite W-W (Olin) ball powders--due to another corporate affilitation. Magnum designations for W-W primers are a fairly recent thing and not all are so designated.

I do not know of any hard and fast rule that says one must always use a certain primer, standard or magnum. What I do know is that certain loads perform better with one or the other and one really needs to try different combinations in order to find the best one.

 

[Ol` Joe]

As long as you are getting good ignition, the milder the primer the better for accuracy in general. Ball powders, large powder charges, and deep cold may call for a mag primer, but you can normally get by without one with `06 sized cases down and normal shooting condidtions.
JMO

 

[Slamfire]

Reloading manuals are guides. At some point in time you will have your own opinions.

I have used Federal, WLR and CCI#34's with great success in medium capacity cases. Basically 243 through 30-06. One lot of primers will give a little more or a little less velocity across my chronograph. Not a problem, I can adjust. I also do not like shooting maximum loads as a primer change or case change can cause blown primers.

Even though CCI#34's and WLR tend to be on the hot end of primers, (I think they are "magnum") you will get sub MOA groups with them if you do your part.

Perhaps if you were shooting some of those huge magnum cartridges, the extra long, extra fat magnums, maybe you would need to use magnum cartridges to get top velocities. With some of the older magnums, maybe not. I have loaded the old 375 H&H with 4064 and with standard primers, and got good groups.

I do believe, but have not proved it, that milder primers give better on target accuracy. This would be a primary concern for paper punchers. However hunting is totally different, and my primary concern would be reliability.