500 S&W Mag loads

[357mag357]

Looking at the reloading data, Alliant's calls for a LRM primer and Hodgdon's uses a non magnum LR primer with all of there powders. I thought H110 and 296 needed a magnum primer to work correctly? What do you think? Has anyone tried Alliant's 300MP?

 

[CaptHank]

I'm using LRMP with H110. No problems yet......

 

[Grumulkin]

H110 and Win. 296 are the same powder but you probably already knew that. They don't require magnum primers in a case of that size.

 

[Dropyourweapon]

I was confused by that for a bit and after looking into it am going with Winchester WLR primers and H110.

 

[Mr.Revolverguy]

Couple of things when reloading this cartridge.

There was brass released early on that does not take rifle primers. The starline came out with brass that was identified with an R next to 500 signifying large rifle primers. Now corbon has a third type of brass. It is very important to identify your brass correctly. Directly from starline's website.

Per Starline website:

"Cor-bon has also tested and recommends CCI 250 primers (Magnum Large Rifle). Our new cases will have an "R" after the "Mag" on head stamp to signify rifle pocket. If you have previously purchased 500 cases without "R" on head stamp and wish to modify, you can use a large rifle pocket uniformer to deepen primer pocket to accept large rifle primers by deepening pocket approximately .006". This will not affect integrity of case. For concerns regarding situation contact Smith & Wesson or Cor-bon as they designed case and subsequently changed it. "

 

[357mag357]

So if my brass does not have a R stamped on it I should use Large Pistol Primers?

 

[Dropyourweapon]

So if my brass does not have a R stamped on it I should use Large Pistol Primers?

Yeah that seems to be what they are saying. The box of bullets I bought and the brass I got from Starline all had the R so that made it a bit easier for me. I guess the other stuff is still floating around but I have not seen it in my short time with the 500.

But even getting the primer pocked figured out then the magnum versus regular large rifle primer thing was a bit confusing. Corbon says to use magnum primers but the load data I have come across says to use regular primers.

 

[Grumulkin]

Six thousandths of an inch isn't that much. I've used large rifle primers in unmodified 44 Rem. Mag. cases without a problem. If I wished to use large rifle primers in Corbon cases without the R, I would probably just try it without primer pocket modification.

 

[FROGO207]

I have also used rifle primers in unmodified cases BUT I am using them in a NEF Handi Rifle NOT in a revolver that could have issues with high primers and them contacting the back of the cylinder housing. That fact would have me modifying my brass to prevent a ka-boom in a revolver.

 

[Grumulkin]

I have also used rifle primers in unmodified cases BUT I am using them in a NEF Handi Rifle NOT in a revolver that could have issues with high primers and them contacting the back of the cylinder housing. That fact would have me modifying my brass to prevent a ka-boom in a revolver.

We're talking six THOUSANDTHS of an inch. Seat the primers with a firm stroke and they will be flush with the case head and they won't explode either.

 

[mahansm]

It only takes a few seconds with a primer pocket tool to get the correct depth for the rifle primer. Starline and others switched over to using rifle primers after some pistol primers failed to withstand the pressures of near-max loadings.

I purchased 60 cartridges with low pressure loads for my .550; the Starline brass had pistol primers/pockets. I bought a reamer for less than the cost of 60 rounds of new brass so that I could use rifle primers in all my reloads.

New brass now has primer pockets with the correct depth for the rifle primers.

 

[Funshooter45]

H110 does need magnum primers IF you're using pistol primers. If you're using rifle primers though, it's not necessary. Standard rifle primers are even hotter than magnum pistol primers.