When would you use a mag primer in 357 ?

[Biggfoot44]

As seen most recently in the Handloader just arrive , related by Brian Pearce.

When you see in a manual that all loads in a magnum revolver cal are loaded with Magnum primers , it is their lawyers at work. The thought process is that if they listed some powders with std , and some with mag , if an inattentive reader substituted mag primers in a max load developed with std , signifigent overpressure could result. So they CYA .There ballisticians actually know better.

Of some of the powders discussed above , 2400 will work fine with std , and develope higher vels at a given pressure , also expressed that with std primers , a heavier charge can be used to reach same pressure level.

Actually , with 4227 and AA#9 it is the reverse. With heavier loads with higer MON, JAN 5, 2015 and pressures closer to their prefered window , std works fine. It is with loads that are substantially reduced with more air space and preak pressures at the lower end of their window , that a mag primer will sometimes reduce ES and improve accuraccy.

My number 1 shooting and handloading partner whas done extensive testing with Lil Gun in .357 and .41 . He gets better accuraccy and lower spreads with std primers. NC doesn't have much subartic temeratures , so no input on sub zero temp effects if any.

 

[John R]

I have Speer loading data for 357 with mag primers for 4227, 2400, and H-110.

 

[Calliope]

The Speer #11 manual recommends magnum primers for 296/H110, 4227, 2400, HS-7, HS-6 and even for W231, but not for HP-38 (???) and others.

I've found the Win WSPM does a great job of getting HS-6 and 4756 to burn more completely.

I think Hodgdon does all their data with magnums for liability reasons. Clays certainly does not need a magnum primer, but they develop their data with mags in case someone uses one.

 

[Moe Mentum]

Around here , magnum primers and standard primers cost the same. So i use whats in stock at the time...

 

[thndrchiken]

You use a magnum primer when your manual tells you too.

Now with that being said unless I'm loading 357 for hunting loads with a 180 gr bullet, I'm loading to 38 sp +p levels for a light target and pd load without heavy muzzle flash.

 

[tops]

In 1965 I started using a standard primer, 15 grs. 2400, 158 gr. bullet and haven't changed. Larry

 

[Skeet 028]

Mag primers??

I think Hodgdon does all their data with magnums for liability reasons. Clays certainly does not need a magnum primer, but they develop their data with mags in case someone uses one.

Yeah...all these companies now are worried about the lawyers for the other side.. Much loading data from the past was much more emphatic in nature I think. But it's like the old saying...speed(and pretty) sells and they were promoting a new(kinda) product. I bought my first 100 lb keg of 4831(70 dollars delivered) from B E Hodgdon in the early mid 60s and used it for everything. They even had reloading data of a sort. Bought the 2nd the next year..still have about 5 lbs of that left.. Loaded almost everything with it...fill 'em all to the base of the neck and seat a bullet. I got a package deal from them once too.4895 and a bunch of primers. Can't remember the price but it was cheap. The primers came from somewhere in Scandinavia ....Still have the wooden crate they came in...via Railway express. Who knows whether they were magnum or standard??? Gosh I'm getting old

 

[tops]

Loaded almost everything with it...fill 'em all to the base of the neck and seat a bullet.

I remember buying H4831 from a guy that bought the large kegs. We loaded 30-06 just like you. Larry

 

[Skeet 028]

Yep..I wore out 7 different 25-06s(before it was a factory cal) a couple of 270s and shot a lot of that in the 06 myself..But with the 06...loaded to the base of the bullet from 150 down..base of the neck with anything heavier.. Lucky we still have fangers huh? I even used it in the 338 Win. I happened to have the 11th one made..darn thing shot great. Kilt my moose and one Dall sheep and kept it handy for ol grizz. Sold it when I moved out of Alaska. I weighed a few charges once when loading the 270 and they came right out to just shy or just above 60 gr...depending on the case.

BTW when I bought primers..mostly CCI I never bought mag primers for the rifle. Never seemed to need 'em..even with 4831

 

[USSR]

When you see in a manual that all loads in a magnum revolver cal are loaded with Magnum primers , it is their lawyers at work. The thought process is that if they listed some powders with std , and some with mag , if an inattentive reader substituted mag primers in a max load developed with std , signifigent overpressure could result. So they CYA .There ballisticians actually know better.

Bingo! It's the powder that determines whether you use a magnum primer or not, not the cartridge headstamp or some reloading manual that wants to play CYA. W296/H110, HS-6, and IMR4227 benefit from a magnum primer or a SRP if using a case that takes SPP's. You use a magnum primer with 2400, and E.K. will be rolling over in his grave!

Don

 

[HorizontalMike]

Vihtavouri N105 with SPM primers and 158g XTPs?

Just went & checked latest load data put out by powder mfgers . IMR / Hodgdon / Win state WSPM primer period in 357 as does Accurate Powder . Alliant states Std primers . The one that throws me is Vihtavouri states SR primers in 357 mag . I could see that in 357 max due to cratering / primer flow @ higher pressures , but have never seen it in 357 mag unless gun had an erroded firing pin bushing or extremely hot loads . And with hot loads usually case separation would also happen .

My question ALSO!
Been procrastinating this past year, as I loaded up on reloading equipment/supplies. I am a first-timer reloader. I've got 16lb of Vihtavouri N-105, 5k of 168gr XTP, and will shortly have BOTH CCI-500 and CCI-550 primers for reloading my 4" S&W 686, thus my conundrum.

• Vihtavouri load data says NO SPMs for any loads, but has load data for 357 w/N-105 w/SP only
• Hornady says YES (WSPM) w/N-105 for XTPs of 110g, 125g, and for 140g FTX, but NO N-105 data for 158g and 180g XTPs.
• Hornady also shows other Vihtavouri powders, ALL with magnum primers(WSPM), including for 158g and 180g XTPs.
• Lee shows N-105 load data for 158g XTPs with only SPs, No magnum primers.
• Lyman lists N-110 & N120 for 158g lighter&heavier loads with SPMs, but NO data for N-105

QUESTION:
Why the big hole in the data for N-105 w/158g XTPs and SPMs?

 

[webley green]

Only time I use it is with W-291, works great.

 

[LRNFP]

I read somewhere that it doesn't hurt, but I have issues with that. I have also loaded 357 MAG by mistake and shot them seeing that they were light loads. the mag primers create more pressure(?) A more interesting fact is I have some Winchester pistol primers that state on the box "for standard or magnum loads" figure that one out.

 

[shil]

I generally go by the book. If a magnum primer is specified in the data, I'll use one, but, depending on the powder, I'll often switch to a standard, or, just initially work the load up with a standard primer. If the recipe calls for a standard primer, you must work the load up again if you switch to a magnum primer. Blastenboomer loads, with, say, H110/W296, always get a magnum primer, or, the Winchester Large Pistol which the company says is suitable for standard or magnum applications.