I am loading 6gr. of unique with a 158gr. cast bullet. All I have are small pistol primers for standard loads. Do I need to get magnum primers?

Do you have any Small rifle primers?
Never used magnum primers, never saw a need.

All the 357 Unique loads on alliant's site use a standard CCI 500 primer.

magnum primers are only required when using certain powers or when the reloading book say to. I myself never use them, because the powers I use don't need them. also I wouldn't use rifle primers in a hand gun, I'm sure they would work just not good reloading practice.

Have never found a need for magnum primers in .357 mag with H110 HS6 or Clays in a 627 4" from mild to wild all worked well with std. small pistol primers......

I load a lot of 357 magnum, I use CCI #500. Allthough If I could get Magnum primers I would like to test the difference?

thewelshm

I use magnum primers in my 357 mag loads no matter the powder I am loading with. The charge might or might not be hotter, depending on the primer manufacturer, but the magnum primers generally have a harder cup that resist high pressure better. I've read that with Remington small pistol primers, the primer charge is the same between #1 1/2 and #5 1/2 primers but the 5 1/2 have harder cups. With that said, I wouldn't have any qualms about using small pistol non-magnum primers with your cast bullets and Unique powder loads in 357 mag.

No, all you need are small pistol primers.

With Unique you don't need magnum primers.

I use 2400 powder, no magnum primer required. Gets velocities close to the 110/296 powders that DO need magnum primers.

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"He was kinda funny lookin'"

I use magnum or small rifle primers in all 357 loads from mid range
to heavy regardless of powder used. It's not that some powders don't
require magnum primers it's that with the long case ignition is better
and consistancy is improved.

357's with CCI 500's for me always

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DoubleRFirearms
FFL

When I shot USPSA open gun in 38 super comp We used small rifle primers because of pressure in a major load so I ended up with 10,000 small rifle primers I've been useing them in my 357 for a while with no issues on a medium to tight 1100 fps load. Just my 2 cents, Joe

Some revolvers, especially those that have had an "action job" or springs replaced, may not strike a rifle primer hard enough to get 100% ignition.
Having said that, I have used rifle primers in my Dan Wesson and Thompson/Center with success but never in a S&W.
I have had Smith's too light to touch off pistol primers.
Mostly it was because I or the gun itself backed off the main spring screw too much.
X-Frames will use a rifle primer but no others are designed for the pressures involved there.

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Nemo

I use SMALL magnum primers when they are explicitly called for(notably with w296/H110), but otherwise don't worry to much about them. I'm getting ready to start playing with AA #9, and I think it generally calls for them. I occasionally use VV N110, which actually generally calls for a small rifle primer(I use it too when called for).

I have used them with my "mild" 357 mag Unique loads as well as with 2400 when I was running low on regular SP primers and plenty of Magnums, but they certainly aren't necessary with powders like Unique and 2400.

I'll also add that I have never used a magnum large pistol primer. Two companies-Winchester and Remington-don't even make them. Winchester primers are explicitly marked "for regular and magnum loads." The charts I've seen show that regular CCI LP primers are nearly as energetic as CCI Magnum SP primers. When in doubt, I grab Winchester LP primers for "hot" loads with 296. This is also a convenient marker for me, as Winchester primers are unplated brass and all the other primer brands I use(CCI, Remington, and Federal) are nickel plated. If I see a handloaded 44 mag or 45 Colt with a brass primer, I know it's most likely a max load.

In a word, no. The only powders that need mag primers are w296/h110, maybe lilgun, everything else runs fine on std.

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NRA Cert. Inst. IDPA CSO

The use of Magnum vs Standard primers really depends on the powder used. Some loads will loose approximately 40 - 50 fps with Non Magnum primers, but if you are just shooting at paper or steel, it doesn't really matter much.

If I have the Magnum Primers on hand I will usually use them, but I have also used Standard Primers when the Mag's were not available. The paper targets never knew the difference........

And for HS-6...

Like said already, the use of a magnum primer is dictated by the powder used, not the cartridge name.

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Freedom is never free!!
SWCA #3437

Nope. Your load only amounts to a .38 if you're using the magnum case. Unique gets along just fine with std. primers.

Larry

I just loaded a bunch last night, unique and small pistol primers.

I use standard primers with my loads of 7.0 grains of Unique and a .158 LSWC in .357 Magnum. BTW they chrono at 1065 fps from my 4" 66.

With that load standand small pistol primers will be fine.

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John

DNS use your standard pistol primers . Yjru will work fine. I not big on mag primers till loads get near the range of 357mag loads when developed. Other wise my under 1300fps loads use federal pistol primers.

I actually was going to use 6.5 to 7gr. as above, but the new manuals, and the alliant web site, all list 6gr. as the max.

The new manuals and the web site do not feature data actually
developed by Alliant due to changes in ownership and marketing. The
low maximum loads listed for lead bullets is because of the softer
swaged bullets used. Older Hercules data went as high as 8.5 grs with
158 gr lead bullets. My Speer #13 manual shows 7.7 grs as max with
a 158 gr Jacketed bullet.

I never loaded much with unique in my 357 hunting days but a friend did years ago and I think 8grs was his load with a 158gr gas checked lead swc . I stayed with old 2400.

All of the early 357mag loads were reduced for safety sake as some handguns did not hold up well if at all. Then the industry has reduced many loads across the line to make higher production runs safer . Lots of handgun ammo out there today that are only a shadow of what they were when first run as production ammo.