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Reloading Question


Waimea

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Are small pistol primers interchangeable with small pistol magnum primers?

 

Thanks in advance for your responses.

 

Waimea (Still learnin' this reloading stuff)

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Conventional wisdom is that magnum primers will give a slight increase in velocity and pressure. So as long as you're not loading at max levels you can use mag primers with no problems. I prefer Federal Small Pistol Magnum primers for light CAS loads.

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Waimea........here's the best answer I found, albeit semi autos.

 

Best Answer - Chosen by Asker

yes, it will work. here is the scoop:

by using a mag pistol primer, you increase your pressures by approx. 10% (note I said Approx.) because some powders burn faster, pressures can be a little higher than that. In most cases, it won't hurt, all you have to do is reduce your load. BUT, in 9mm, which operates a very high pressures to begin with, it can be dangerous. My suggestion is this, start with the minimum load for your powder as listed in the manual. Load a mag full, and test fire them. Check closely for signs of over pressure (extruded primer etc) before slowly increasing to about the mid range. I would not go any higher than that. And, this is all contingent upon your pistol being a modern quality made one. Not some cheap pistol like Lorcin etc. No manufacturer is going to tell you it is ok because of liability. And I'm not telling you to do it for the same reason, just advising you what I have done with both pistol and rifle.

shoot safe

 

See ya at Eustis

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Thank you Pards.

 

So if I reduce my gunpowder by 10% to compensate for the increase in pressure and velocity of the magnum primers that's getting a free round of powder for every 10 rounds. Dang that's like money in the bank.

 

CS, Missed you at Howey. Went back to 49r double strong side instead of that cross-draw stuff. Hope you got yer house back together.

 

Waimea

 

:FlagAm:

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Thank you Pards.

 

So if I reduce my gunpowder by 10% to compensate for the increase in pressure and velocity of the magnum primers that's getting a free round of powder for every 10 rounds. Dang that's like money in the bank.

 

CS, Missed you at Howey. Went back to 49r double strong side instead of that cross-draw stuff. Hope you got yer house back together.

 

Waimea

 

:FlagAm:

 

 

It doesn't work like that.

For example, you can't just use 10 magnum primers and expect to get the same load using no powder at all.

 

PLUS, you can't switch from a Mag primer to a standard and expect to increase your powder charge by 10%.

 

..........Widder

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My experience says a ten percent decrease in powder would be too much for same velocity. I am sure it is powder dependent tho. For my 38 spl Bullseye loads I reduce powder by about 5 percent for same 750 fps velocity for Mag versus std Fed primers.

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I ran a test last year, intentionally loaded squib loads. Loaded 3 of each brand and type of small pistol primer that I had in my cabinet. Same size bullets, same brand of brass, and same pistol(old model Blackhawk). After I fired each round I measured the distance the bullet traveled down the barrel until it stopped. The primers used were: CCI small pistol, Winchester small pistol, CCI small pistol bench rest(very old), Federal small pistol magnum, Federal small pistol match, and even CCI small rifle. Surprisingly, they all traveled down the barrel close to the same distance, except for the Federal small pistol magnums, they fell short of the others by about .325 of an inch. Therefore the theory of using magnum primers to push a bullet out of the barrel in case of a squib was busted. And, magnum primers add to velocity is not really true. They might burn hotter which could possibly ignite powder quicker for a better burn, thus a higher velocity. In CAS I don't really see any difference between primers, in other games perhaps.

It was an easy test to perform, your results may vary. Back to the original question, I would not change my powder charge regardless of the primer type unless I had a chronograph available in order to compare velocities to original rounds.

 

LL'

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Ok. I guess switcing to the magnum primers will take a bit a experimenting the the powder loads.

 

I warn't really serious about all the money I was gonna save on gunpowder anyhow. (Not too serious, insert tears here). Gunpowder's not my biggest expense in reloading anyway. I got one 14 oz jar of Clays last year and I still got about 1/4 of it left.

 

Widder....I ain't quite sure what yer meanin by this:

 

"For example, you can't just use 10 magnum primers and expect to get the same load using no powder at all."

 

I can only fit one primer in each shell so ya lost me on that one. Maybe yer sayin it's like the dentist tells the patient to brush at least 10 times a week so he decides to brush 10 times on Saturday night. I ain't sure.

 

Waimea

 

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There are a lot of factors that are going to determine what effect the magnum primers have. There's no hard set rule that you can just drop the powder charge 10% and use a magnum primer and get the same results. The caliber you're loading for, case capacity, pressure of the load and powder you're using would all have some effect on it.

 

I'm loading a minimum charge of Titegroup in a 38spl case, which leaves a LOT of empty space in the case. I use magnum primers in the belief that it may ensure more efficient powder ignition. Does it make a difference? I don't even know, I've never chrono'd them to see. But it doesn't hurt. Now in a high pressure caliber with a small case like a 9mm, there may be a much bigger effect than in a 38spl with it's big mostly empty case.

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I use published loads with published specified primers, I reckon those who put it together know a whole heap more than I do on the subject and have the time, facilities and money to test things out.

 

But that's just me.

 

Then again if it's the zombie Apocalypse, and I am out of loaded ammo and all I can get my hands on is small pistol magnum primers, you bet your aunt Gertie's girdle I'm gonna load them.

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Waimea,

I have used Federal small pistol primers exclusively for years until a year or so ago when finding any primers was difficult. When I finally found some they were Federal small pistol magnum primers. I was concerned that changing to them might affect my point of impact or change pressures. So I contacted Federal's technical dept. and asked what I should expect by only changing primers. Their answer was that there should be no difference in pressure or velocity. The difference in the two is that the thickness of the metal cup of the magnum primer is thicker than the standard primer. They offered no explanation as to why that is. They did suggest that an overly-lightened main spring may not consistently ignite the magnum primers and that I should test for that. I did chronograph equal loads with the two different primers and found virtually no velocity difference. I have shot only the magnum Federal primers for a year now and have had 100% reliability. The magnum primers do seem to feed more reliably in my Dillon 650 reloader.

 

This information created a lot of discussion among my shooting buddies and the difference in regular vs. magnum primers may be different with brands

other than Federal.

 

Hope this helps. Talk to you at the next match...

 

Delta Glen

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Waimea,

I have used Federal small pistol primers exclusively for years until a year or so ago when finding any primers was difficult. When I finally found some they were Federal small pistol magnum primers. I was concerned that changing to them might affect my point of impact or change pressures. So I contacted Federal's technical dept. and asked what I should expect by only changing primers. Their answer was that there should be no difference in pressure or velocity. The difference in the two is that the thickness of the metal cup of the magnum primer is thicker than the standard primer. They offered no explanation as to why that is. They did suggest that an overly-lightened main spring may not consistently ignite the magnum primers and that I should test for that. I did chronograph equal loads with the two different primers and found virtually no velocity difference. I have shot only the magnum Federal primers for a year now and have had 100% reliability. The magnum primers do seem to feed more reliably in my Dillon 650 reloader.

 

This information created a lot of discussion among my shooting buddies and the difference in regular vs. magnum primers may be different with brands

other than Federal.

 

Hope this helps. Talk to you at the next match...

 

Delta Glen

 

 

After hearing this from Delta Glenn I also checked with Federal thinkin maybe they had a tech that stayed at Holiday Inn express when talkin to DG but I got same answer,then I and Santa Fe River Stan separately chronoed loads changing nothing but Mag & non magnum primers with same result no difference, SFRS had some Winchester Magnum Primers which were actually a little hotter than the Federal.

 

 

 

AO

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Thicker primer cups on the mag primers would make sense, because magnum loads generate higher pressure, and you do NOT want to consistently have pierced primer cups (that will erode firing pins, pin bushings or recoil shields). A thicker primer cup will withstand the higher pressures.

 

Those Federal technicians make a great point - it COULD take a stronger hammer spring to fire the mag primer. If you have tuned your revolver light, and it NEEDS Federals, it may not like Federal Magnums.

 

Good luck, GJ

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I have standard 17# Wolf springs in OM Vaqueros so that's not going to be an issue.

 

I am down to my last 100 box of primers so it's time to buy some more. :unsure:

 

I was just looking around on the various sites and found where the regulars were sold out but the magnums were available. Don't want to make a mistake when buying that many of something.

 

Appreciate all the thought put into these responses.

 

Waimea

 

:FlagAm:

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Waimea:

 

sorri for the curve ball. I won't try to explain cause I would probably just confuse meowndangself... :lol:

 

Anyhow, here is some info I 'once' read:

 

In pistols, magnum primers are not 'hotter' but rather have a longer flash time. This helps for more of a complete burn of your powder (which in turn, gives more uniform velocities, not necessarily a high velocity). I don't have that reference but in my early years of learning to reload, I got that piece of info in some book/magazine I was reading.

 

Now for my personal experience:

 

In my Cowboy loads, I use one of our common powders, CLAYS.

I established my original loads using standard primers (Federal and Winchester).

Everything seemed fine until COLD weather came around and I was getting a few erradict discharges and noticing some incomplete burning of my powder.

 

I switched to Magnum primers and the colder weather seem to have no effect on my loads.

 

I have since started using nothing but magnum primers in my Cowboy loads of which I am very satisfied.

 

I often chronograph my loads and in doing so, I didn't notice any measureable increase in velocities.

 

Well, this is just from my personal experiences.

 

Hope this helps.

 

 

..........Widder

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Following is my experience with a chrony and Federal primers:

 

10 rounds each, Uberti 20” Carbine (.38 Spl., 125 Gr. RNFP, Clays, 0.3 Gr. < Max.)

Primer Type, Average (Mean), Extreme Spread, Standard Deviation

Federal Standard,969, 38, 12

Federal Magnum, 976, 55, 14

 

Hardly any difference.

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Just my .02

 

A couple years ago when the country went nuts over a new administration and everything was in short supply, all that was available locally was Federal small pistol magnums. I had only used standard Federals to that point so I did the reduce powder by 10% and work back up thing. After about 500 rounds of experimenting my new loads (using magnums) are within 1/10th of a grain powderwise of what I was using with the standard primers when achieving the same velocity over a Pact MkIV chronograph. So I just went back to my old powder load using the magnums and didn't look back. Only real difference I could see was slightly less unburnt powder on and around the cylinder chambers

 

Regards

 

:FlagAm:

 

Gateway Kid

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Sounds to me like Magnums are a big thumbs up.

 

Thanks, Pards!:)

 

Waimea

 

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