Large Pistol Primers Standard and Magnum

Prof Young · October 21, 2012, 08:41 PM

Loaders:

So I have two types of large pistol primers. I can't recall the brand names but one is for magnum and one is labeled for standard or magnum. What's the difference? Can I use the ones labeled magnum in standard loads?

Live well, be safe
Prof Young

jepp2 · October 21, 2012, 09:54 PM

If you use a magnum primer in a load that was developed with a non-magnum primer, it "could" develop higher pressure. So good practices would suggest you drop your starting load slightly to compensate.

The magnum primers were developed for the harder to ignite powders like H110.

A good reference can be found here.

publius · October 23, 2012, 11:17 PM

Yes, drop your powder charge if you use mag. primers in a standard load. On the other end, use magnum primers for mag. loads. I used some standard primers on some heavy .45 loads with H110 and it did not fully ignite, bullet stuck in barrel.

Zekest Crowe · October 24, 2012, 12:26 AM

I think what the OP is asking is:

Winchester makes large pistol primer that is clearly marked on the box "STANDARD OR MAGNUM"

When I saw that box I was confused too! How can it be Standard -OR- Magnum?! I passed on the Winchester brand and purchased Remington...

**Unclenick** · October 24, 2012, 04:57 PM

Prof Young,

There are different approaches to making a primer magnum. Some make it burn hotter and faster by just increasing the amount of priming mix. Others change the mix to add fuel components so it makes more gas for pressurizing a large case, but actually has lower brissance. The WLP primers may be of the latter sort, staying gentle enough for target loads, but making enough gas and flame for magnum loads. As near as I could tell when I used them about 20 years ago in the .45 ACP for target loads, Winchester WLP's presented no significant performance change over my more usual Federal 150's. I notice they've not made a standard/magnum combo primer like that in any other size, so it seems like it's something that only works out for them in the Large Pistol format with their priming mix.

Read this primer on primers.

October 21, 2012, 08:41 PM	#1
Prof Young Senior Member Join Date: August 22, 2007 Posts: 488	Large Pistol Primers Standard and Magnum Loaders: So I have two types of large pistol primers. I can't recall the brand names but one is for magnum and one is labeled for standard or magnum. What's the difference? Can I use the ones labeled magnum in standard loads? Live well, be safe Prof Young

October 23, 2012, 11:17 PM	#3
publius Senior Member Join Date: January 25, 2005 Location: Mississippi/Texas Posts: 2,349	Yes, drop your powder charge if you use mag. primers in a standard load. On the other end, use magnum primers for mag. loads. I used some standard primers on some heavy .45 loads with H110 and it did not fully ignite, bullet stuck in barrel. __________________ "Suppose you were an idiot, and suppose you were a member of Congress, but I repeat myself." Mark Twain

October 24, 2012, 04:57 PM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 9,153	Prof Young, There are different approaches to making a primer magnum. Some make it burn hotter and faster by just increasing the amount of priming mix. Others change the mix to add fuel components so it makes more gas for pressurizing a large case, but actually has lower brissance. The WLP primers may be of the latter sort, staying gentle enough for target loads, but making enough gas and flame for magnum loads. As near as I could tell when I used them about 20 years ago in the .45 ACP for target loads, Winchester WLP's presented no significant performance change over my more usual Federal 150's. I notice they've not made a standard/magnum combo primer like that in any other size, so it seems like it's something that only works out for them in the Large Pistol format with their priming mix. Read this primer on primers. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Patron Member

October 21, 2012, 09:54 PM	#2
jepp2 Senior Member Join Date: December 24, 2008 Location: Loveland, CO Posts: 1,016	If you use a magnum primer in a load that was developed with a non-magnum primer, it "could" develop higher pressure. So good practices would suggest you drop your starting load slightly to compensate. The magnum primers were developed for the harder to ignite powders like H110. A good reference can be found here.

October 24, 2012, 12:26 AM	#4
Zekest Crowe Member Join Date: June 24, 2012 Location: WA Posts: 36	I think what the OP is asking is: Winchester makes large pistol primer that is clearly marked on the box "STANDARD OR MAGNUM" When I saw that box I was confused too! How can it be Standard -OR- Magnum?! I passed on the Winchester brand and purchased Remington...