magnum primer question

[deadeye dick]

Just bought a Ruger Blackhawk in 38 sp. 357 mag. The Lee manual just states in their spec drawering the use of small pistol primers in the 357 section. When are magnum primers used? Is it safe to use standard primers? Nowhere in the book does it explain the difference between mag. and standard primers. Any help would be appreciated.

 

[rcmodel]

Mag primers are only necessary when using very slow magnum class Ball powders like W-296 & Hodgdon H-110.

For all other flake type powders, like Unique, 2400, etc, use standard primers.

Or whatever your loading manual says to use.

rc

 

[deadeye dick]

Thanks RC. Read another section of the book and as you said standard primers are to be used. My Bad

 

[mahansm]

H110/296 (same powder) will not light consistently in .357 Magnum with standard small pistol primers. About 1 in 6 will misfire, leaving a bullet either stuck in the bore or bridging the bore/cylinder gap. Magnum primers light the powder all the time.

Reduced loads may fail to ignite, as may loads with a light bullet and poor bullet tension/light roll crimp.

You can get almost the same performance from 2400 using standard primers and the loads can be reduced to taste.

 

[OH_Spartan]

H110 and w296 are the same powder? Are they still both sold under those two names?

 

[rcmodel]

Yes, and Yes.

Hodgdon powder packages both H-110 and W-296 with the same bulk powder made by the St. Marks Powder Co in Florida.

It has been exactly the same powder since 2006.

If you look on their website, the data is exactly the same now.

rc

 

[243winxb]

Remington Primers

See "in pistol cartridges." I always use a magnum prime for 38 & 357. No pierced primers since. The S&W hammer nose is still like new.

 

[32_d3gr33s]

I shoot 9, 38 and 357. I couldn't get my hands on standard pistol primers, so all I shoot is magnum primers.

 

[ArchAngelCD]

H110/296 (same powder) will not light consistently in .357 Magnum with standard small pistol primers. About 1 in 6 will misfire, leaving a bullet either stuck in the bore or bridging the bore/cylinder gap. Magnum primers light the powder all the time.

Reduced loads may fail to ignite, as may loads with a light bullet and poor bullet tension/light roll crimp.

You can get almost the same performance from 2400 using standard primers and the loads can be reduced to taste.

Sorry but I can't agree with you. Yes, a magnum primer should always be used with H110/W296 and HS-6 too but not using one will not cause a 1 in 6 misfire rate. If you do get a misfire it won't be from the standard primer. You will however get a much cleaner and complete burn with a magnum primer and the pressures and velocities will be much more consistent. You might have a problem in sub-zero temperatures when not using a magnum primer with W296/H110 but other than that, not 1 in 6 misfires.

 

[ArchAngelCD]

243winxb,
Remington is the only primer manufacturer who has a standard pistol primer you can't use in a pistol cartridges. Same goes for their 6 1/2 SRP. IMO that's just strange and a little confusing too if you didn't know about it. I think their 6 1/2 primers are a waste of time since they are only suited for the 22 Hornet.

 

[Grumulkin]

Well, after having used standard and magnum primers in loading for multiple cartridges large and small with ball and other powders, my experience has been as follows:

1. I have NEVER had a misfire when using a standard primer with a ball powder. The ONLY time I ever stuck a bullet in a bore was when I forgot to put powder in a case and I've changed my reloading practice since then.

2. Accuracy wise, I've seen no rhyme or reason as to why accuracy is improved with a stardard or magnum primer whether with ball or other type of powder.

3. If there is excess residue in a barrel after shooting, it's because the pressure is too low for optimal powder burn. It can be cured by increasing the powder charge and doesn't necessitate a primer change. Be advised though, that in some guns, low pressure is the norm and you'll always get some residue with safe loads.

 

[mahansm]

ArchAngel,

When I tried loading 296 with 125 grain JHPs in .357 magnum rounds using Winchester small pistol primers, about 1 in 6 did not ignite in my S&W 686. The primers fired but I was left with a bunch of yellow colored powder and a stuck bullet. All rounds loaded with Winchester small magnum primers (no other change) worked just fine.

 

[abq87120]

As I understand it, mag primers just burn a little longer. Not a hotter flash. It's OK to use mag primers where normally an SPP is called for. I doubt that SPPs will be very successful in mag rounds. But, do your homework before taking my word.

 

[4895]

I didn't chrony my results but I have used small pistol primers with 296 before and I couldn't tell a difference between those primers or mag primers. I have also used small pistol in small rifle rounds without a problem. I have also used small rifle primers as small pistol mag primers. Don't take my word as absolute by any means. YMMV.

 

[joneb]

The problem in question may not show up until the the temperature falls.

 

[7mmb]

Speer's data for 357 Magnum specifies whether or not to use a magnum primer depending on powder. Some powders, like H110/296 and HS6, they always use magnum primers. With 2400 and N110 they advise to never use magnum primers. Most other manufacturers use magnum primers with all of their 357 Magnum data. Stick with published data and you won't go wrong. Magnum primers aren't necessary with every powder but if the data you are using was developed with them you'll be fine using them.

 

[ArchAngelCD]

As I understand it, mag primers just burn a little longer. Not a hotter flash. It's OK to use mag primers where normally an SPP is called for. I doubt that SPPs will be very successful in mag rounds. But, do your homework before taking my word.

Magnum primers both burn slightly longer and slightly hotter than standard primers but not enough to cause nuclear explosions... Note, each company's primers will do so to different levels so as with all changes you make in a recipe, drop the powder charge back a little and work back up for safety.

 

[Lloyd Smale]

standard primers will work with ball powders IF you use loads near the top end of the scale. They DONT work with reduced loads and ball powders. You might still get them to go bang but dont expect much in accuracy. 2400 is a middle of the line powder. Ive seen some loads that liked mag primers and some that liked standard. With that powder i usually try both to fine tune a load. For the most part with 110/296, aa9,wc820 and hs6 i use mag primers for all loads. They cost the same so its kind of silly not to.

 

[Marlin 45 carbine]

better safe than sorry.
use std primers with flake and dot powders only.

 

[USSR]

And, just to stir the pot a bit, VihtaVouri's .357 Magnum load data calls for small rifle primers.

Don

 

[243winxb]

Stir the pot....

 

[357 Terms]

I use small rifle primers with V.V. N110, works great in my 357 hunting and SD loads.

 

[ArchAngelCD]

Stir the pot....

Oh sure, rub it in that primers were only $1.29/100 a little while ago and not over $4.00/100 like now! Cheapest I have left on the shelf are Winchester SPM primers @ $15.99/K. The bulk are $18.99/K and $19.99/K...

 

[joneb]

I am working on a reduced 357 mag. load with Penn's 140gr RNFP premium grade cast bullets. My first loading was 9.7gr of Accurate #7 with CCI 500 the accuracy was ok and the velocity avg. was 1,035 FPS with a SD of 34.
I will try a few with CCI 550 with 9.4gr of #7 and see how those do, and work with Accurate #5 with standard primers for a 1,050ish fps from a 2.75" barreled Ruger Sec.Six.
For me working on a load is as much fun as shooting it

 

[ArchAngelCD]

I am working on a reduced 357 mag. load with Penn's 140gr RNFP premium grade cast bullets. My first loading was 9.7gr of Accurate #7 with CCI 500 the accuracy was ok and the velocity avg. was 1,035 FPS with a SD of 34.
I will try a few with CCI 550 with 9.4gr of #7 and see how those do, and work with Accurate #5 with standard primers for a 1,050ish fps from a 2.75" barreled Ruger Sec.Six.
For me working on a load is as much fun as shooting it

Even though Accurate powders are ball powders they don't seem hard to ignite so I see no reason to use a magnum primer in that AA#7 load. Most reloaders don't even use a magnum primer with AA#9.