9mm and Magnum primers

[gzig5]

I'm going to have a use small pistol magnum primers until I can locate or trade for some standard SP. I'm starting from scratch anyway so I'll start low, but I'm curious if any powders react differently than others when used with mag primers in general. I'll be selecting from W231, Unique, Bullseye, and 700x. Got a couple others that I used in 10mm but I think for this application the four listed make most sense. Leaning towards Bullseye, but I have a bunch of 700x. Not looking for a barn burner load, just something that will shoot 110 and 135 lead bullets accurately and reliably. So other that starting a touch lower, anything to look out for?

[Jniedbalski]

I use 3.5 to 4 gr of bullseye with 115 to 130 gr. bullet.my lee 105 gr tc I use 4.0 to 4.2 gr of bullseye. With magnum primers cut back .2 gr if using the 4.0 load. 3.8 with mag primers shoot good in my guns.

[Wheelguns 1961]

I use 4.4 grains of unique with a 135 grain large hollow point, and a standard primer. With a magnum primer, I would start at 4.0 and work up. The load I listed is a great one in my 9mm autoloaders.

[pworley1]

Unless you plan on loading to the maximum recommended load, use them and enjoy.

[Meatpuppet]

I load magnum and standard small pistol primers in 9mm USPSA loads interchangeably.

147gr Blue Bullets, 3.3gr VV N320, 1.13OAL (890fps). Not top end loads, but chrono speeds do not increase noticably with magnum primers, although standard deviations narrow down with them.

[243winxb]

WSPM , Lee 356-120-TC , 700X - 3.4 gr. listed maximum, COL 1.030" IN 9MM Luger. Primers shows less pressure @ 3.4 then factory ammo. Mixed brass.

Yes, i worked up from 2.9 grs.

Speer & Hodgdon have the lead bullet data.

[ioon44]

I use WSPM and CCI 550 primers in 9 mm and .45 ACP for IDPA and USPSA loads using Alliant Sport Pistol.

As with any component change reduce 10% and work up.

[mdi]

With the many new reloaders and scarce components (primers especially!) this is a very common subject. I have played with standard vs magnum vs rifle primers in a few different calibers and for me, "Reloading 101" I always proceed carefully and begin a new load workup for any change of any component. One of the best info-videos I've seen so far dealing with standard/magnum/rifle small primers; https://www.youtube.com/watch?v=NGVRGsoOr6k&feature=youtu.be&ab_channel=SuperVel

[bangerjim]

As stated. down 10% for starters. Work up - - - but NOT to max load listed for standard primers!

I use mag primers in all sorts of handgun loads.......just 10% less listed loads.

The just burn a bit hotter, so you do not need as much powder. And they work great for shooting HMG boolits with enlarged holes.

But this this current shortage, most are probably not doing fun HMG or sneeze rounds!

banger

[JM7.7x58]

In my 40 s&w Shield I have a load that malfunctions/jams at 5.8 grains of Herco with a standard Winchester SP primer, but functions well at 6.0 grains of Herco.

I switched primers with this load and tried Rem 6 1/2 SR primers. Reduced powder back to 5.8 grains and again had malfunctions/jamming. Went back to 6.0 grains and it again stopped jamming.

In this situation I really didn’t see any difference when changing primers.
Your mileage may vary.

JM

[gzig5]

Thanks for all the replies. Spent a little time tonight getting the dies adjusted and did five each of four increments of Bullseye with each bullet. Stayed well below the max loads in the Lyman books. I think the 135 started at 3.0gr and the 105 at 3.4gr. Ran some dummies of the 135 through the Canik and seemed to feed well. The driving bands seem to need to be right at the mouth for them to plunk in the chamber, and the flare can't be too aggressive. I haven't been able to procure a proper 9mm shell holder yet, all the vendors are out and I'm not paying Ebay 4x markup prices. I'm using the one from my 6.8 SPC and it is close enough to get the job done until something turns up or I get tired of waiting and make one in the lathe. At least I'm up and running.
Talked to a friend I shoot Highpower with and he has a brick of SP primers and is short on SR so I'll swap him some of my SR stash and won't have to be overly conscious of the primer issue as I move forward.

[fredj338]

At max loads anything & everything can matter. I ran some chrono tests with diff powders & swapping std for magnum primers. What I found was a little surprising in that faster powders showed less vel change than slower powders. So for light loads of fast powder, I dont sweat swapping them out. If loading powders on the slower side, it would be prudent to drop the charge 1/10gr or 2/10gr & work it up over the chrono.