[rcd567]

I'll start off by saying I've been reloading for about 35 years, but not for the 10mm. I'm new at this caliber. Anyway, I've been reading up on the loads and such for different bullet weights and powder. I usually do all my reloading for the year in January, February, and March.

That being said...I've found a bunch of folks swear by magnum primers for the 10mm. I realize you can use them, but is there much difference pressure wise between using a magnum primer or a standard primer? I've got both so it's no big deal, just curious what most of you folks use?

As always, thanks for your time.:wavey:

 

[JPP]

I use Winchester Large Pistol Primers, not the Magnums.

 

[Poppa Bear]

I'll use either one. The magnum will give you a couple more FPS. More importantly it will do a better job of igniting a slow powder by getting the flame out into the case farther. To me that is the biggest issue, some loads like a bigger flame to be more consistent. You might get a 50 FPS spread with a standard primer and 15 FPS spread with a magnum primer. A different load might have the same spread whether you use magnum or standard.

 

[cigarman454]

I use large pistol also. I have been told if you use magnum primers to reduce the load by 10% because of the pressure.

 

[Taterhead]

I used more mag primers in the past, but now only use them for certain loads with Accurate #9 powder. I have found that mag primers seem to cause relatively higher pressures without a corresponding increase in velocities. With a standard primer, I have been abel to increase the charge and corresponding velocities.

Standard deviations on velocities have been, in some cases, lower with mag primers. But along with that comes extra case expansion for a given velocity. However, for the most part, I find a given charge and bullet combo that groups well and has a satisfactory velocity. Standard deviations on velocities have not been a critical data point for pistol function, in my view. Now shooting rifle bullets beyond 1000 yards is another story.

I have found that 800-x, in particular, spikes pressures with mag primers. That has been the most notable situation in my side-to-side tests. Standard primers are designed to ignite charges in cartridges that hold a much greater quantity of powder than the relatively small 10mm auto case. Accurate #9 is one of the slowest burning powders for 10mm so it works well with 350s. However, in doing some load re-works, I am finding that standard primers work well too with surprisingly low deviations on velocities.

I use CCI 300 primers for the majority of applications. Followed by WLPs and CCI 350s.

 

[Kwesi]

Winchester LPP's chrono 20 FPS over my CCI's. Win does not make a magnum but are hotter than other LPP's. I use Win for my 10mm.

 

[No Mercy]

I use CCI 350's in the majority of mine, especially with 800x loads.

 

[DWARREN123]

I use CCI #300 LPP. I like them but before using Magnum LP I would work the load up to make sure there is no problem with the bullet, powder or primer.
When reloading always go safe! :supergrin:

 

[offsidewing]

Funny, I just loaded up two hundred rounds today. I accidentally loading the first one hundred rounds with CCI 350 magnum primers. New Starline Brass, 180gr Noslers, 10.3gr of Blue Dot, OAL 1.252". When I went to get primers for my second one hundred loads, I realized I used the 350's by mistake. Loaded the second hundred rounds with CCI 300 primers.

With that charge, am I going to to have excessive 'unsafe' pressure using using the magnum primers?

 

[Taterhead]

Funny, I just loaded up two hundred rounds today. I accidentally loading the first one hundred rounds with CCI 350 magnum primers. New Starline Brass, 180gr Noslers, 10.3gr of Blue Dot, OAL 1.252". When I went to get primers for my second one hundred loads, I realized I used the 350's by mistake. Loaded the second hundred rounds with CCI 300 primers.

With that charge, am I going to to have excessive 'unsafe' pressure using using the magnum primers?

My suggestion would be to load a few relays at lower charges and work up to the 10.3 gr charge. For me it is automatic when changing components: reduce and re-work.

Doing this will prevent you from pulling the bullets. Odds are you will be fine, but good find out the right way.

 

[_The_Shadow]

Funny, I just loaded up two hundred rounds today. I accidentally loading the first one hundred rounds with CCI 350 magnum primers. New Starline Brass, 180gr Noslers, 10.3gr of Blue Dot, OAL 1.252". When I went to get primers for my second one hundred loads, I realized I used the 350's by mistake. Loaded the second hundred rounds with CCI 300 primers.

With that charge, am I going to to have excessive 'unsafe' pressure using using the magnum primers?

Your rounds will be just fine with that charge weight of Blue Dot! I load more than that using 200Gr XTP's and they are Good-To-Go even in my stock G-29 barrel.

 

[Jitterbug]

I use 300's or WLP's, interchangeably (same mild to moderate loads) depending on what's available at the local funshop, when I get around to loading AA9 I'll go with the 350's for the reasons stated by Tater.

 

[hubcap500]

Follow Taterhead's 2nd post suggestion to work up to the charge weight with mag primers. Whatever you use, don't indiscriminately swap ANY components without working up. A safe load in someone else's gun may be unsafe in yours. You can reload your ammo and/or guns, but not eyes, fingers, or other body parts. BTW, I use WWLPP's in my Starline brass. CCI's are too tight fitting in the primer pockets.

 

[OhioGlockMan]

I switched to using winchester WLP's for loading all large handgun rounds. It's a dual purpose mag and standard primer, and I find it does not raise pressures as much as the dedicated magnum primers. Takes all guesswork out about second guessing yourself "hmm should have I used a mag or std. primer". And were talking a small 10mm case here (compared to a .44 magnum case). Keep in mind winchester WLP's are designed to ignite winchester 296 powder inside a big 44 mag case just fine, and in my experience they do. I don't think you would ever need anything more for the smaller 10mm case