Hi Guys,... I am new to reloading and I am baffled as to why some reloading recipes call for magnum large rifle primers and some only large rifle primers....then still some call for bench rest primers...
To keep my quetion simple,... What Powder applications? and Why? do you use magnum primers, large rifle primers and bench rest primers....
All responses will be appreciated.
thankyou
ckm

Well, Usually, magnum primers are called for with either Ball powders and/or slow burning extruded powders. Typically, with large loads, not with 223's and such. The mag primer is hotter meaning more fire to light the charge of powder. Ball powders tend to be harder to get lit vs extruded powders. Also, with the new super capacity magnums like the Ultra mags where there can be 100 grain charges of slow powder, a mag primer is welcome. As for the BR primers, the high pressure cartridges like the 17 Rem often pierce primers unless the thicker cupped BR primer is used. Like the 71/2 Rem primer, which has thicker metal just for this.

At times a change of primer can tune a load where it was otherwise not shooting well. Most of the time that isn't necessary.

Do keep in mind that the primer, being different in strength, can cause a load to be excessive pressure if changed. I once tested two loads from my 22-250. The difference was Fed 210 primer vs Winchester WLR. I got 280fps more velocity using the Fed primer! Surprised me. Now this load was developed with the Fed primer. Had I loaded origionaly with the WLR then changed to FED primers I could have a problem.

Any time you change any component in reloading, lower the load and test them....never assume. Good luck and have fun!!
Tyler

Any time I start working-up a new load I always start with Remington "regular" primers. After I have found the load that satisfies my needs I then take the same loading data and load 5 with each other primer available. (Winchester, CCI, Federal, Remington magnum, Winchester magnum, CCI magnum, Federal magnum).

If any of the "other" primers shoot better groups, then I rework the loading data using those primers.

As for Benchrest primers, I haven't found that they perform any better than either more conventional standard or magnum primers.

In essence, primers have two parameters that are relevant in the selection process. They vary in "brisance", or explosive power, and they vary in flame duration.

Magnum primers have more of one or both, to uniformly ignite heavier, or harder to light charges (slow burning Winchester ball powders come to mind).

Bench rest primers tend to be low on the brisance scale, and made with a little more "tlc" to increase consistency. I tend to use CCI BR2's or Federal 210's for my large rifle primers, WSR's for my small rifle primers. HTH, Dutch.

[ 10-14-2003, 17:34: Message edited by: Dutch ]

Ok thanks guys, I think I understand now.
thanks again.
ckm