magnum primers versus regular?

[navylawdog]

A local gun shop announced that they have some small pistol magnum primers in stock. I was just wondering if these could be used in any load that would normally use standard primers?

[Hairy Chest]

A local gun shop announced that they have some small pistol magnum primers in stock. I was just wondering if these could be used in any load that would normally use standard primers?

No.  You must reduce the load to use mag primers.  If it is a .38 Spl using Std primers and max load, then it would be prudent to go only to starting loads, in that gun. 

[navylawdog]

Okay thank you. Then it wouldn't really work too well for any of the calibers I would be using it for. I might pick some up just to load some .38's for my Marlin 1894C.

[Hairy Chest]

Okay thank you. Then it wouldn't really work too well for any of the calibers I would be using it for. I might pick some up just to load some .38's for my Marlin 1894C.

For the rifle I would look for a slower powder, like 800X.  The only use for a mag primer I can see would be in a short barrel anything, snub nose to 4" barrels, where anything you do to burn the powder faster is desirable.  Just in some guns, like a S&W alloy frame non +P rated, don't swap a mag primer for a standard with a max load.  Use the starting load only.  The gun is the limitation. 

[geezerbiker]

It doesn't always make a big difference. I've used them in .380 auto and 9mm and ended up with the same load as before.  I know this isn't normal but it can happen.  I'd say buy a 1000 and you'll find a use for them.  In the Klinton years, I used small rifle primers in my .357 mag revolvers with no problems at all...

Tony

[navylawdog]

I have several different calibers I could use them in like .32 acp, .380 acp, 9 mm, and .40 s&w. Then not to mention .38 special and .357 but those loads would be for a rifle and the .40 would be for a hi point carbine. So....?

[geezerbiker]

I think the worst case is that you'd use a little less powder in those pistol rounds.  I've never loaded .32 auto but they worked well in my daughter's .380 commercial model Russian Makarov.

Tony

[gr8ful]

It would be prudent to start off with the MIN load and work up until you reach your desired performance.  You will likely experience slightly higher pressures and velocities with any given powder charge.

[Hairy Chest]

I have several different calibers I could use them in like .32 acp, .380 acp, 9 mm, and .40 s&w. Then not to mention .38 special and .357 but those loads would be for a rifle and the .40 would be for a hi point carbine. So....?

The only time you need mag primers is when you light off a big case of powder, like 475 Linebaugh.  None on your list will do better with mag primer.  Groups will open up.  That is because a mag primer creates too much pressure and pushes the bullet out of the case before full ignition.  If 44 magnum likes a std primer best, then why would any caliber beneath it use it?  Cold weather.  Are you in the Arctic? 

[navylawdog]

Thanks for the help everyone. I will probably just wait for some standard primers to arrive. Some things have been rolling in lately so maybe it won't be too much longer.

[geezerbiker]

None on your list will do better with mag primer.  Groups will open up.  That is because a mag primer creates too much pressure and pushes the bullet out of the case before full ignition.  If 44 magnum likes a std primer best, then why would any caliber beneath it use it?  Cold weather.  Are you in the Arctic?

My experience says otherwise.  I substituted  small rifle primers and small mag pistol primers in .380, 9mm, 38 special and .357 mag loads.  I did start over and worked up and none of my guns shot any worse..  None shot better either but at the time, they wouldn't have shot at all if I hadn't used different primers.  I don't remember how much less powder I used.  I know I used less in .380 and 9mm but the .357 mag was no change.   

I also used large magnum pistol primers in .45 auto but these were cast bullet loads at less than max charge to begin with and I noticed no change with the mag primers.  Once again, at the time it was all I could get so it was these or no shooting.   I even considered making .45 auto cases from cut down .308 Win so I could use large rifle primers but it never came to that...

In the G.W. Bush years I stocked up on primers and if funds weren't a bit tight, I would have doubled what I bought...

Tony

[Dand]

I thought I read where some rifle primers might have a deeper cup than pistol primer and even fully seated might sit a little "proud" above the case base raising concerns for clearance and accidental firing in some situations.  I haven't noticed it myself but then I try to stick with the recommended primer.  I too stocked up on anything I could get in the last primer scare and ended up with a bunch of mag small pistol primers.  Haven't used them much but then I shoot a fair bit of 357 where they work fine - tho more often I use standard with Unique and other fast to mid range powders.  I'd be very careful in those little auto cases as pressures can rise really fast with minor powder or primer variations.  Like others have said, start at the very bottom.  You might want to search the Handloader Magazine for articles about primer effects.  Seems like Brian Pierce wrote on the subject. Also, the Lyman manual has good discussions on variations in components. Safety first.

[Bullseye]

I cannot agree with mag primers always making a cailiber shoot worse.  I load IMR 4227 in my 44 mag using CCI mag primers and get a wonderful group, the older speer books listed it this way.  The newer speer books show a regular primer and I made the seitch.  My accuracy went to heck, switched back and got good groups again.
 
I also shoot CCI mag primers and IMR 4227 in the 22 hornet (because I had some at the time) which everone says will give you terrible accuracy with such a small case.  When I consumed my mags I switched to standards and my accuracy went south.  Went back to mags and it came back.
 
I just do not believe any blanket statements about primers and accuracy can be made.  Experiment, start low, find an accurate round.

[geezerbiker]

I thought I read where some rifle primers might have a deeper cup than pistol primer and even fully seated might sit a little "proud" above the case base raising concerns for clearance and accidental firing in some situations. 

That's with large rifle primers, they're deeper than large pistol primers.  You would have to either ream a pistol primer pocked deeper or use modified rifle brass to use them in a handgun. 

I use the recommended primer most of the time but when I couldn't get the right primer, I figured out what would work.  More often than not, I could get a very good shooting load with hotter than spec primers.

Tony

[rockshooter]

just FYI- I use small pistol magnum primers in .223 in a bolt gun- works just fine. I have substituted magnum/non-magnum primers in handguns for years. No issues at all, but I never load max loads. Given that, the advise to start low is sound.
Loren

[mdi]

I have had to use magnum primers instead of standard primers. I have loaded .38 Specials with magnum primers, but I reduced loads back to the suggested starting load. I only had to use 100-150 magnum primers in the .38, and did not notice any pressure signs with re-developed loads. Small pistol primers are the same height as small rifle primers, but large rifle primers are about .008" taller than large pistol primers, .115" vs .123"  http://www.jamescalhoon.com/primers_and_pressure.php

[gypsyman]

Sierra manual states to back off 10% from whatever you might have been using. gypsyman

[cooter74]

How about going the other way? I want to load some .357 mag but don't have and can't find SPM primers, but have regular SPP. How would they do in the .357 mag?

[gypsyman]

cooter74, depends on the powder your going to use. H110/W296,(same powder), you should use a mag primer. If your using something like Bullseye or Unique, a std. primer works just fine. gypsyman

[Blackhawker]

 
This makes me wonder; will the scarcity of loading components create an onslaught of experimental loaders?  Will I be safe at the range when standing next to other shooters that have done such experimenting?  Will enough accidents begin to occur with experimental loaders in which the "gun grabbers" will begin a ban on loading?      

....food for thought.

[dakotashooter2]

One of my manuals has loads listed for .38 sp, 9mm and .40 that call for magnum primers. The loads are out there if you search for them.

[Dixie Dude]

I have used small magnum pistol primers in 223 with no problems.  I have read that the magnum primers add about 100-200 fps speed to a given load over a standard primer.  Also, different powders do the same thing.  Like most everyone said, with a magnum primer in a small case, start with the MINIMUM recommended load for the given powder, then work up if you don't like the group. 
 
For instance my Lyman manual 48th edition says for a 100 gr fmj 380 auto bullet:
 
2.6g of Unique minimum load pushes 725 fps at 12,000 C.U.P. pressure with standard primer.
 
3.6 g of Unique maximum load pushes 1,013 fps at 15,200 C.U.P. pressure with standard primer.
 
If you use a magnum primer with 2.6g of Unique it might push it to 925 fps or maybe 825 fps. 
 
That is why you should start with the minimum load.

[Hairy Chest]

I have used small magnum pistol primers in 223 with no problems.  I have read that the magnum primers add about 100-200 fps speed to a given load over a standard primer.  Also, different powders do the same thing.  Like most everyone said, with a magnum primer in a small case, start with the MINIMUM recommended load for the given powder, then work up if you don't like the group. 
 
For instance my Lyman manual 48th edition says for a 100 gr fmj 380 auto bullet:
 
2.6g of Unique minimum load pushes 725 fps at 12,000 C.U.P. pressure with standard primer.
 
3.6 g of Unique maximum load pushes 1,013 fps at 15,200 C.U.P. pressure with standard primer.
 
If you use a magnum primer with 2.6g of Unique it might push it to 925 fps or maybe 825 fps. 
 
That is why you should start with the minimum load.

If you have a max load with a std primer, then a minimum load must not be exceeded with mag primer. 

[Dixie Dude]

You are not reading what I said.  You must use a minimum load with a magnum primer to start with to see what it is doing .  A chromograph would be good, then you work up the load if you can.  I didn't say use a maximum load with a magnum primer, that is stupid.  I was using the book to show using a STANDARD primer with a MAXIMUM load what you got.  So, because the magnum primer is stronger, you must start with a minimum load.  Just that alone would probably put you half way to maximum. 

[Hairy Chest]

You are not reading what I said.  You must use a minimum load with a magnum primer to start with to see what it is doing .  A chromograph would be good, then you work up the load if you can.  I didn't say use a maximum load with a magnum primer, that is stupid.  I was using the book to show using a STANDARD primer with a MAXIMUM load what you got.  So, because the magnum primer is stronger, you must start with a minimum load.  Just that alone would probably put you half way to maximum.

I read everything you wrote.  All I'm saying is there are times when we stick with the book such as when reloading .38 spl.  If the gun is not +P, then we need to be very careful.  Or when it is +P we are equally careful.  It is the same with shotgun, we don't mix and max and work up anything.  You can do anything you desire.  A .38 spl will come apart long before you see pressure signs "working up."  The book values are good for developing your brass.  Once it is there, expanded at the head the correct amount, then you can mix and match and work up to your heart's desire.   

[SHOOTALL]

The 38 spl. come/came in many different guns. When the mod 60 S&W hit the streets some were converted to 357 mag. They were not +p rated back then. I doubt they would come apart with a min. load . A turn of the century Colt with bored thru. cyl. meant for 38 Colt will chamber a 38+P or 357 mag. for that matter making it a likely hand grenade.
 That said why mag primers ? some powders need the extra boost to get a consistent burn with some types of powder. Sometimes they are substituted in cold weather . Of course with light loads some powders become inconsistent or dangerous with M primers.
 Now to say everyone should stay with the book and what it list is contrary to history. What should be said is if you don't know or have the ability to find the information and understand it then stick to what is listed. But we need to understand that those who publish manuals don't have the time to check every suitable component in every mix. There are experienced hand loads who do understand how things work and they experiment with in safety limits. No don't just try this with out knowledge . But if no one experimented look at all the wild cats that went factory we would not have today. Or loads .