Winchester Pistol Primers are labeled for either regular or magnum use. Can Federal Small Pistol Magnum primers be used in the same way?
Primer Question
- Thread starter halvenut
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I've used magnum primers when I couldn't get standards and noticed no difference
rockquarry
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You might notice a significant difference with maximum or near maximum loads.
Dieseltech56
Member
I have used Federal SPM primers in all my 357 mag loadings since day one. Never really noticed anything significant
Alk8944
US Veteran
You are "Mixing metaphors" as it were. Winchester Large Pistol are listed for standard or magnum loads as Winchester only makes the one Large primer. This is not the case with their Small Pistol primers.
For all practical purposes any small sized primer can be used in any handgun cartridge that uses small primers. This includes Small Pistol, Small Pistol Magnum, AND Small Rifle, either standard, magnum or match makes no significant difference. The exception would be when loading absolute maximum loads in high-intensity cartridges such as .357 Magnum, 9mm +P, .40 S&W, and similar cartridges.
And before some (inevitably) jumps in and says you will get mis-fires, FTFs with small rifle primers in handguns, this is simply not true! I have fired literally thousands of rounds of re-loaded ammunition using small rifle primers in both revolvers and semi-automatic pistols over many years and have had exactly zero FTFs from this or any other cause that cannot be specifically identified!
What you will see, but only if you chronograph your loads, is one primer or another can give better (lower) extreme spreads, standard deviation, and a small change in velocity for the load. Accuracy may be better with one primer or the other, but this is true depending on manufacturer too.
Short answer, YES. There is no safety issue except as mentioned above.
For all practical purposes any small sized primer can be used in any handgun cartridge that uses small primers. This includes Small Pistol, Small Pistol Magnum, AND Small Rifle, either standard, magnum or match makes no significant difference. The exception would be when loading absolute maximum loads in high-intensity cartridges such as .357 Magnum, 9mm +P, .40 S&W, and similar cartridges.
And before some (inevitably) jumps in and says you will get mis-fires, FTFs with small rifle primers in handguns, this is simply not true! I have fired literally thousands of rounds of re-loaded ammunition using small rifle primers in both revolvers and semi-automatic pistols over many years and have had exactly zero FTFs from this or any other cause that cannot be specifically identified!
What you will see, but only if you chronograph your loads, is one primer or another can give better (lower) extreme spreads, standard deviation, and a small change in velocity for the load. Accuracy may be better with one primer or the other, but this is true depending on manufacturer too.
Short answer, YES. There is no safety issue except as mentioned above.
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S&WIowegan
US Veteran
During the recent difficulty obtaining Federal small pistol primers, I used Federal small pistol magnum primers instead. This was for minor power factor loads in revolver shooting. I chrono everything and could not see a significant difference. However, I did see some instances of no-bangs in my light trigger revolvers with the magnums but only occasionally. It is critical to achieve deep seating of primers when using race revolvers.
When loading 38 Super ammunition for high pressure racegun semiautos, we all routinely used small rifle primers to prevent primer piercing.
When loading 38 Super ammunition for high pressure racegun semiautos, we all routinely used small rifle primers to prevent primer piercing.
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OP
Thanks to you all for your helpful replies. These were obtained when primers were difficult to find. I don't load anything to the maximum loads. I just needed to know if there was anything special that I needed to do and if I could use them. Thanks for all of your help.
DWalt
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I have used SR primers in handgun loads for many years, no ballistic differences evident vs. use of SP primers. And no misfires either. You really can't use LR primers as substitutes for LP primers as they are thicker and protrude above the case head. But I can't imagine any problems with using LPM primers in all loads where you would normally use LP primers.
It depends on the powder used. Some powders are a bit more difficult to ignite (H110 is one) and Magnum primers are suggested. Just because it says "Magnum" on the barrel, "Magnum" components are not always needed. The only powders I use Magnum primers with are WC820 and W296...
fredj338
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The simple answer is no they are not interchangable or the same. If you are loading low to midrange ammo, then it wont move the pressure needle much. Allprimers are not the same.
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Typically, in addition to a "hotter" primer mix producing higher temperatures to ignite certain primers, Magnum primers often also have a harder/thicker primer cup to better resist higher pressures. Obviously, small rifle primers are going to have harder/thicker cups to resist even higher pressures.
I'll defer to the guys who've used both. Many years ago I mistakenly bought 100 magnum primers and used them in lead bullet loads with a powder that was easy to ignite. I noticed flatter primers and more leading in that particular case. YMMV depending upon powder, case and bullet.
I'll defer to the guys who've used both. Many years ago I mistakenly bought 100 magnum primers and used them in lead bullet loads with a powder that was easy to ignite. I noticed flatter primers and more leading in that particular case. YMMV depending upon powder, case and bullet.
BigMoneyGrip
Member
A while back, I did a test on primers. In 9mm, I used one powder and one bullet, difference being charge weight and primer. I loaded ten rounds with each primer and charge weight. Over about ten different charge weights, the magnum primer offered no discernable difference in velocity. However, the SD and ES were a lot closer with the magnum primer. In a few instances, the ES was in the single digits.
After I use up my primer stock, I'm gonna start using the magnum primers.
After I use up my primer stock, I'm gonna start using the magnum primers.
ArchAngelCD
Moderator, SWCA Member, Absent Comrade
No they can not. Only the Winchester Large Pistol primers are recommended by the manufacturer for both. That does not include the Win small pistol primers.
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When you get down to it...
Having two different kinds of primers is really more complicated than is needed. A magnum primer will do everything a standard primer does and more. It probably costs a millionth of a cent to add a little more material to make it stronger, when it's really just as easy to back off the powder load a few tenths of a grain. In the past the companies wanted to sell every product they could, but nowadays they want to simplify manufacture, packaging and inventory. I predict that one day standard primers will be hard to find and the shelves will be full of 'universal' primers.
Having two different kinds of primers is really more complicated than is needed. A magnum primer will do everything a standard primer does and more. It probably costs a millionth of a cent to add a little more material to make it stronger, when it's really just as easy to back off the powder load a few tenths of a grain. In the past the companies wanted to sell every product they could, but nowadays they want to simplify manufacture, packaging and inventory. I predict that one day standard primers will be hard to find and the shelves will be full of 'universal' primers.
About the only thing I have noticed when I substitute Mag primers for standard is the rounds burns cleaner.
DWalt
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Not on the topic of Magnum vs. regular pistol primers, but not too long ago I related here the story of my test of .270 Winchester loads which were exactly the same except for the primer. I used 130 grain bullets and a slow Norma powder (bullets and powder weight matched). Average MVs were identical (within a few ft/sec) for both standard and Magnum LR primers. But those loads using standard primers grouped a bit more tightly at 100 yards. My verdict - no difference in performance due to primer type, even with the slow powder.
dave201
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Primers
There is a difference, thou you may not notice it
Primers that are to hot will cause a double spike in the pressure curve.
The first spike is the bullet actually being unseated by the pressure from the gas expansion from the oversized primer
The second spike is the powder starting to burn.
This is not the kind of ignition I want for the best performance
As with lot numbers, whether it be with powder or primers, there is a difference.
Same with reloading data. It's just a guideline
Take 3 manuals, add the three starting point load totals together and divide by 3=Average.
The Hornet is a very touchy round to load
It works best with small pistol powders.
I can go on
My experiments thru the years seems to verify that exceptions are pretty common in this hobby
Be Careful. Ruptured primers, high pressure gases, and flying metal is not what I consider a fun day at the range
Some people just have more luck than others.
With reloading it's not a question of if, it's when your luck runs out if the rules are ignored. Watch some of the antics on You Tube
The manufacturers seem to know
Warranties caused by reloads are null and void
There is a difference, thou you may not notice it
Primers that are to hot will cause a double spike in the pressure curve.
The first spike is the bullet actually being unseated by the pressure from the gas expansion from the oversized primer
The second spike is the powder starting to burn.
This is not the kind of ignition I want for the best performance
As with lot numbers, whether it be with powder or primers, there is a difference.
Same with reloading data. It's just a guideline
Take 3 manuals, add the three starting point load totals together and divide by 3=Average.
The Hornet is a very touchy round to load
It works best with small pistol powders.
I can go on
My experiments thru the years seems to verify that exceptions are pretty common in this hobby
Be Careful. Ruptured primers, high pressure gases, and flying metal is not what I consider a fun day at the range
Some people just have more luck than others.
With reloading it's not a question of if, it's when your luck runs out if the rules are ignored. Watch some of the antics on You Tube
The manufacturers seem to know
Warranties caused by reloads are null and void
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dave201
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Example one
Auto Rimless
Headspaces on the case mouth
The primer ignites starts the bullet moving and then powder starts burning
The primer has started the slide moving back before main ignition
That means the round has lost its headspace and will actually go off out of battery
Most autos have unsupported chambers except for competition
race type guns
The primer can actually set back since it's not crimped like machine gun ammo.
This can cause bulged cases, jammed rounds, stovepipes, failure to feed, sooty empties. The round is suppose to go off in battery to push a certain spec recoil spring back.
Ignition is suppose to be smooth. You are not teaching a new driver how to use a clutch.
Reloading is a great hobby. Learn as much as you can and make perfect reloads. You will be rewarded with great ammo that actually works better than factory. Don't let your first experience sour you because you had bad information. Reload like you would have to fly it
EXCUSE THE LONG WINDED RANT, But reloading ammo is a passion I've had since I was 11.
Ahhhhhhh The smell of either when I open a can of IMR
Auto Rimless
Headspaces on the case mouth
The primer ignites starts the bullet moving and then powder starts burning
The primer has started the slide moving back before main ignition
That means the round has lost its headspace and will actually go off out of battery
Most autos have unsupported chambers except for competition
race type guns
The primer can actually set back since it's not crimped like machine gun ammo.
This can cause bulged cases, jammed rounds, stovepipes, failure to feed, sooty empties. The round is suppose to go off in battery to push a certain spec recoil spring back.
Ignition is suppose to be smooth. You are not teaching a new driver how to use a clutch.
Reloading is a great hobby. Learn as much as you can and make perfect reloads. You will be rewarded with great ammo that actually works better than factory. Don't let your first experience sour you because you had bad information. Reload like you would have to fly it
EXCUSE THE LONG WINDED RANT, But reloading ammo is a passion I've had since I was 11.
Ahhhhhhh The smell of either when I open a can of IMR
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So much depends on what you want to do. A Magnum primer can start the bullet forward with it's extra oomph as powder is igniting. This can deter accuracy especially if your crimp is minimal. A magnum primer is needed for many ball powder regardless of the cartridge designation as magnum as is a heavy crimp. Most of the time it doesn't matter but it can with light loads and a minimal crimp increase your group size by a small amount. With most pistols and shooters you may not notice but put it on a rest and it is there.
