Question on .357 magnum and standard primers

["Spoon"]

I am loading up my normal hunting round and I am now out of magnum primers. I use a 158 gr SWC with tightgroup or unique depending on what I have available at the time. Am I going to have a noticeable reduction in fps with my typical load? I am shooting them out of a carbine.
Thanks.

[Thumbcocker]

I can't speak to velocity for your load but I have never used magnum primers in .357 or .44. FWIW

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["Spoon"]

I didn't expect really a difference with the powders I am using. Now with my J-words w296 loads I fear that may be a different story.

[45DUDE]

In my Marlin carbine I use magnum rifle primers with a warm load but not with lead.

[slohunter]

I've never used magnum primers, even with heavy loads of 296/110. No unburnt powder.

[badguybuster]

I only use magnum primers with Lil Gun and H110.

[gunseller]

When it gets cold slow powders lime 296/H110 (same powder) can be hard to lite. I don't think a 357 holds enough powder to create a problem. I also have never used mag primers in 357, 44 mag or hot loaded 45 Colt. I load with 2400 and have shot at -20 F with no problems. Firearm and ammo were outside in truck over night. With the powders you are using I think the differance in velocity will be within your standard deviation. Have fun and don't ginve primers a second thought.
Steve

[downzero]

You probably shouldn't have been using magnum primers with those powders anyway. I only use them with H110/W296. All other loads that I use call for standard primers.

["Spoon"]

Thanks for all the responses. I appreciate the friendly way members teach around here. Definitely not like that everywhere. Thanks again.

[358429]

Shoot em up! Should be fine considering you are using faster powders. I'd be curious to know if this change in your loading may cause them to group better[emoji3] or even more interestingly if the group dispersion did not change at all

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[Thumbcocker]

Yup. Let us know if anything changes.

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[Daekar]

I have used everything from small pistol magnum primers to small rifle magnum primers in 357mag and never really noticed a difference. Maybe if you're pushing your loads on the ragged edge of disaster it might make a difference... but at that point, just step up to 357max.

[NSB]

Magnum primers weren’t developed for cartridges designated as some kind of magnum. Magnum primers are used for powders that are shaped/coated in a way that makes them harder to ignite. There’s no direct correlation between magnum cartridges and magnum primers. Some powders that call for magnum primers are WW296 and H110 (both the same powder). Read your loading manual and use what they call for. You don’t need a magnum primer for most powders.

[farmbif]

just out of old habbit I use mag primers with certain powders such as 296 and 4227, blc2, 2520, 748 and on--most all ball powders
but I'm wondering with this question you ask. do you work up your loads, starting low and working them up towards max using published load data manual or online from bullet or powder manufacturers. you say unique, it doesn't need a mag primer. but online hodgdon/imr load data calls for magnum primer using titegroup powder in 357mag
what are you hunting with your 357 mag?
most of the time when people say "hunting loads" they usually refer to getting close to or maximum potential out of a cartridge. I dont think either of the powders you mention quite do that for 357 mag. in my limited knowledge and opinion some powders that do help max out performance in 357 mag are AA no 9 or 4100/enforcer, h110/296, 4227, 300 mp, 2400 and there are some others.

[megasupermagnum]

Assuming a normal 4"-6" revolver, with H110 you could go up to 1400 fps or so with that bullet. With Unique, you are around 1200 fps with a max load. I have no idea what it would do from a carbine. It is a noticeable difference, yes. If they shoot better, then go for it. If you don't trust H110 or similar with standard primers, then I see no reason not to use Unique.

[dale2242]

There is no need for magnum primers with tite group or unique.

[robg]

use the primers the powder manufactures recommend.no need for mag primers with most alliant powders.try 2400 if you want more speed again std primers .ive cronoed some of my loads .165g gc boolit 13.5g = 1550fps 2400 .195g gc =1350fps .125g jhc 16g 2400=1780fps .all fired from my win trapper.

[Moonie]

I agree, no need for mag primers until you start using the slow ball powders like W296/H110. 2400 is a great one to use and there is no need for mag primers for it either.

you can use non mag primers with W296/H110 but as has been mentioned, in cold weather you would want to, I believe Hodgdon recommends mag primers for W296/H110.

[nueces5]

Hello, in Argentina the Mag primers have been gone from the shelves for a long time. I think I have been reloading with std primers for about 10 years, and although it shows that it develops its full potential, what it develops is enough for me.
I have friends who have told me that they prefer to use a faster powder for their 357, instead of W296. Since they have had ignition problems.

[rockrat]

Do you have any small rifle primers? Thought that spm primers were equivalent to sr primers.

[Winger Ed.]

Do you have any small rifle primers? Thought that spm primers were equivalent to sr primers.

I'd have to look it up to double check, but I think rifle primers are a tiny bit 'taller' than pistol primers.
But I've used them in .357Mag before too, and they did fine for me.
If anything, the primer sat flush instead of being slightly recessed in the primer pocket.

[1006]

Large Rifle are taller than Large Pistol, but I think all small primers are the same dimensions- roughly.

[Walks]

There is no need for magnum primers with tite group or unique.

Yep

[M-Tecs]

I'd have to look it up to double check, but I think rifle primers are a tiny bit 'taller' than pistol primers.
But I've used them in .357Mag before too, and they did fine for me.
If anything, the primer sat flush instead of being slightly recessed in the primer pocket.

For small rifle/pistol primers they are the same size. Large rifle nd large pistol are different heights.

https://ballistictools.com/articles/primer-pocket-depth-and-diameter.php

[JoeJames]

For small rifle/pistol primers they are the same size. Large rifle nd large pistol are different heights.

https://ballistictools.com/articles/primer-pocket-depth-and-diameter.phpThat is my understanding at least as far as CCI primers are concerned.

[Dom]

As long as I can remember 2400 has been my go to powder for 357 & 44mag. Never have used a mag pistol primer . Never have wanted for more power or accuracy.

[Norske]

Standard Winchester primers are made to ignite graphite coated, double base ball powders.