Magnum Primers For magnum Rifles

butta9999 · July 6, 2008, 05:08 AM

Is it necessary to use a magnum primer in all magnum rifle calibers. I do use it in my .300 win mag , do i have to allow when measuring powders. Do the magnum primers contribute to much more pressure than a normal large rifle primer.

ligonierbill · July 6, 2008, 07:17 AM

Depends on the powder, not the caliber. That said, I notice Speer calls for magnum primers in most of their .300 Win Mag loads. With the slow powders I load in 7 mm Rem Mag, I always use the magnum primers. It's consistent ignition of slow burning powders, and no, you do not need to change the measure of powder. The question of higher pressure has been debated here before, mostly regarding use of mag primers where a standard primer is specified. I've seen no reports of high pressure indications, but why try. Load the spec primer, work up from minimum, and test your loads, as always.

Hoss52 · July 6, 2008, 02:03 PM

I recently ran several 300 WM loads over my chrono comparing reg & mag primers. NO difference in velocity with 4 different powders, which tells me that all were igniting perfectly well. I have done similar tests with other calibers, but none of the short/fats, with similar results.
I think primers are the least important of the variables in reloading. I simply have never been able to discern a significant difference in handguns, shotguns, or rifles. I have handloaded for nearly 40 years, and run thru several thousands of rounds every year.
Only argument that might make sense is during real cold weather hunting, then maybe a little extra spark could be helpful.
In closing, I have never seen a situation where the use of mag primers were a detriment. Again, I think primers are the least important of the variables in reloading. So, go with whatever makes you the most comfortable, or gives you the most confidence.

butta9999 · July 7, 2008, 12:51 AM

Great feed back thanks boys. It makes sense to me aas well just needed to see if other people were on the same page as me. Ive got some brass tumbling now for the .300, gonna load some 180gr nosler accubond with 76 gr of RE-19 behind it. See how i go.

July 6, 2008, 05:08 AM	#1
butta9999 Senior Member Join Date: June 29, 2008 Location: Melbourne, Victoria, Australia Posts: 692	Magnum Primers For magnum Rifles Is it necessary to use a magnum primer in all magnum rifle calibers. I do use it in my .300 win mag , do i have to allow when measuring powders. Do the magnum primers contribute to much more pressure than a normal large rifle primer.

July 7, 2008, 12:51 AM	#4
butta9999 Senior Member Join Date: June 29, 2008 Location: Melbourne, Victoria, Australia Posts: 692	Thank you Great feed back thanks boys. It makes sense to me aas well just needed to see if other people were on the same page as me. Ive got some brass tumbling now for the .300, gonna load some 180gr nosler accubond with 76 gr of RE-19 behind it. See how i go.

July 6, 2008, 07:17 AM	#2
ligonierbill Senior Member Join Date: May 20, 2007 Posts: 2,451	Depends on the powder, not the caliber. That said, I notice Speer calls for magnum primers in most of their .300 Win Mag loads. With the slow powders I load in 7 mm Rem Mag, I always use the magnum primers. It's consistent ignition of slow burning powders, and no, you do not need to change the measure of powder. The question of higher pressure has been debated here before, mostly regarding use of mag primers where a standard primer is specified. I've seen no reports of high pressure indications, but why try. Load the spec primer, work up from minimum, and test your loads, as always.

July 6, 2008, 02:03 PM	#3
Hoss52 Member Join Date: December 30, 2006 Posts: 17	I recently ran several 300 WM loads over my chrono comparing reg & mag primers. NO difference in velocity with 4 different powders, which tells me that all were igniting perfectly well. I have done similar tests with other calibers, but none of the short/fats, with similar results. I think primers are the least important of the variables in reloading. I simply have never been able to discern a significant difference in handguns, shotguns, or rifles. I have handloaded for nearly 40 years, and run thru several thousands of rounds every year. Only argument that might make sense is during real cold weather hunting, then maybe a little extra spark could be helpful. In closing, I have never seen a situation where the use of mag primers were a detriment. Again, I think primers are the least important of the variables in reloading. So, go with whatever makes you the most comfortable, or gives you the most confidence.