Magnum primers

[trying2learn]

I hope this is the right area. Hopefully it is. I have tried searching and reading everything I could but can't get a for sure answer. I remember reading somewhere that you can use magnum pistol primers as a reg rifle primers. Is that correct? I found a place selling all sizes of magnum primers for about 20 bucks for 1000. Granted they are federal but I grabbed a box of small and large magnum primers. Figured if I could do that then all was good other wise I can go back and get the other two sizes for my rifles and be good on pistol primers also. Heck if I can do that I will go back and get more pistol magnum primers and cover all my sizes.

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[fredj338]

NO! Never use a pistol primer in a rifle round. The cups are thinner, NOT designed for higher rilfe pressures. You might get away with it in something like the 45-70, but not higher pressure rounds. This does NOT apply to handgun rounds fired in rfiles. The pressrues are still the same.

[trying2learn]

Ok thank you very much. I will just go get the ones for the rifles. Makes it easier. Thanks again.

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[Dale53]

There is another problem. Large rifle primers are "taller" than large pistol primers. The pistol primers, if seated properly, would be way below the case head, possible leading to misfires, etc.

Keep a supply of primers for each of the cartridges you need. There are no shortcuts.

Dale53

[M-Tecs]

It can be done but you are risking a pierced primer if you use it in a high pressure rifle load since the primer cups of pistol primers are thinner and softer than rifle primers. I would not use them in a load that’s over 40,000 psi. Also LR are .008 taller than LP.

http://castboolits.gunloads.com/showthread.php?139615-Difference-between-Large-Rifle-and-Large-Pistol-Primers

[trying2learn]

There is another problem. Large rifle primers are "taller" than large pistol primers. The pistol primers, if seated properly, would be way below the case head, possible leading to misfires, etc.

Keep a supply of primers for each of the cartridges you need. There are no shortcuts.

Dale53

I know it sounded like it but I was not looking for a short cut. More of I was thinking the magnum pistols were the same as reg rifle primers so that it would be safer to use the magnums in the rifle instead of pistol if that makes sense like it did in my mind. I understand there is a difference and the deal is so good I don't mind picking up the other ones I need. Just wanted to make sure. I was going to be right whoch ever way I went. Thank you again.

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[Dale53]

Trying2learn;
You probably read about someone using SMALL pistol primers in rifles. The outside dimensions of small pistol primers and small rifle primers are the same (cup thickness differs, however). However, the large primers are different - they have the same outside diameter but the rifle primers are taller.

There are those that recommend small pistol primers in the .22 Hornet. That is an application that works for many. That is probably what confused you.

At any rate, you should be good to go, now.

Dale53

[shotman4]

i use the mag primers In what they are made for
hand gun for hand gun -- and rifle for rifle
I drop about 1 gr of powder for mag primers , could be more for a low charge like a 9mm or 380
but as said dont use pistol, in rifle case, or reverse

[trying2learn]

Dale that very well might have been what it was. That was why I was needing thr clarification, I plam to drop at least 1 gr charge and work up. As if it was the first time I ever loaded the caliber just to be safe.

Thank you all for the responses. Now to get back to that shop.

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[M4bushy]

i use the mag primers In what they are made for
hand gun for hand gun -- and rifle for rifle
I drop about 1 gr of powder for mag primers , could be more for a low charge like a 9mm or 380
but as said dont use pistol, in rifle case, or reverse

1 grain drop? Seriously. I've tested mag primers vs std primers in both 45acp and 9mm. The mag primers were barely 100 fps faster than the reg primers with the same powder charge.

[trying2learn]

I was told when I bought them to go ten percent down from my normal charge and work up. Some will be close 1 full gr and others might be as low as .25 a gr. At least I know that's close to true. From someone trying to sell me something earlier.

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[MGySgt]

1 grain drop? Seriously. I've tested mag primers vs std primers in both 45acp and 9mm. The mag primers were barely 100 fps faster than the reg primers with the same powder charge.

How much pressure increase do you think was needed to drive the 9mm or 45 acp bullet (or boolit) 100 feet per second faster?

Just courious.

[fcvan]

Adjusting the charge between standard and magnum primers is just good practice. I generally use magnum primers for wax and hot glue boolits :)

[M4bushy]

How much pressure increase do you think was needed to drive the 9mm or 45 acp bullet (or boolit) 100 feet per second faster?

Just courious.

With a powder such as tight group in 45acp with a 230gr fmj about 1500cup the only way you could get into trouble is if you are at max loads with reg primers. tight group for instance list a starting load at 4.4 gr with a max load of 4.8 so backing it off 1 gr and you are off the scale.

[turtlezx]

??? just swapping sp for sp mag primers in the 45auto bumps the fps 100
that correct??????
if so i'll be pushing 1200fps with the 160gr boolits

[chris in va]

IIRC CCI SPM is the same as SR. Call CCI to verify, just something another board member found out.

I can't wait to get my ProChrono to verify a few things.

[MGySgt]

With a powder such as tight group in 45acp with a 230gr fmj about 1500cup the only way you could get into trouble is if you are at max loads with reg primers. tight group for instance list a starting load at 4.4 gr with a max load of 4.8 so backing it off 1 gr and you are off the scale.

yes you are off the scale - but you started off the scale by using magnum primers vice standard. A practice I find dangerous unless you back it down. I would rather a boolit stuck in the barrel vice a cracked slide (45 ACP).

Just me -

[blackthorn]

For what it is worth, this is a bit of information on primers gleaned from the net, relating to a conversation on June 14, 2009 between the original poster and CCI's tech department discussing the technical differences between their primer types. With respect specifically to the cup thickness, formula differences, and formula amount differences between their #500 (SP), #550 (SPM), and #400 (SR);
●Cup thickness: The #500 has a thinner cup than either the #550 or #400; however, both the #550 and #400 have the same cup dimensions (including thickness).
●Flash powder formula: All three sizes use the same formula for the flash powder.
●Flash powder amount: The #500 has a slightly smaller amount (3 micrograms) than the #550 or #400 which both have the same amount.
The tech rep confirmed that on comparison, the SR primers could be used as an acceptable substitute for the SPM primers because the #550 and #400 appeared to have the same specs, same dimensions, same cup thickness, same formula, and same amount of flash powder. Further the SPM primers were slightly taller than the SP primers and were exactly the same dimensions as the #400. Information from CCI indicated that SR primers were suitable for reloading both rifle and pistol magnum or not. The only exception being for custom pistols where the thicker rifle cup contributed to misfires, which has only been documented as a problem occurring in custom race pistols.

[M4bushy]

??? just swapping sp for sp mag primers in the 45auto bumps the fps 100
that correct??????
if so i'll be pushing 1200fps with the 160gr boolits

Not sp primers lp primers. fwiw winchester only makes one kind of lp primers and the box says for standard and magnum loads

[44man]

How much pressure increase do you think was needed to drive the 9mm or 45 acp bullet (or boolit) 100 feet per second faster?

Just courious.
Yeah, right! It takes a LOT of pressure to gain 100 fps. Good call.
Both cartridges mentioned do best with standard SP primers---yes even the ACP.

[M4bushy]

Yeah, right! It takes a LOT of pressure to gain 100 fps. Good call.
Both cartridges mentioned do best with standard SP primers---yes even the ACP.

Ok, so your an expert. Just relaying what my chronograph detected.
During the last primer shortage all i could get my hands on was mag primers so i did some experimenting. No the primer alone probably doesn't make the
Velocity increase, it's the rate that the powder is ignited that can cause the spike.

[44man]

Ok, so your an expert. Just relaying what my chronograph detected.
During the last primer shortage all i could get my hands on was mag primers so i did some experimenting. No the primer alone probably doesn't make the
Velocity increase, it's the rate that the powder is ignited that can cause the spike.
Exactly, you are correct. It is the very small cases that the mag primer is the worst choice in.
But ignore the spike for a second, primer pressure alone can move a boolit before ignition and that causes other problems. It will increase air space a different amount between rounds shot.
Even a standard LP primer can be too much in the ACP, my tests have shown a standard SP primer works better.
I refuse to use a mag primer in my .44 mag or .45 Colt even with 296. They instantly triple groups.

[44man]

Ok, so your an expert. Just relaying what my chronograph detected.
During the last primer shortage all i could get my hands on was mag primers so i did some experimenting. No the primer alone probably doesn't make the
Velocity increase, it's the rate that the powder is ignited that can cause the spike.
Exactly, you are correct.
But ignore the spike for a second. Primer pressure alone can move out a boolit before good ignition. That changes air space from shot to shot.
Tests have shown the tiny cases can not absorb the pressure from the primer. The ACP works better with a standard SP primer.
I refuse to use a mag primer in the .44 mag and .45 Colt even with 296.
With a rifle, LP mag primers can work fine depending on case size and powders. Large cases need LR and larger yet need LR mag primers. Primers of all kinds can take a lot of pressure, I have taken LP mags to over 50,000 psi without making them flat. That is not the reason, it is flame front, the amount of heat, primer pressure, powder choice and the size of the case.
Primer thickness can be an issue with very strong mainsprings or wrong shaped pins that can puncture them. Primers for an AK must be very tough or the gun will slam fire. Floating pins need very hard primers.
Beside the point anyway. Too much primer pressure in tiny brass is wrong just like not enough in large cases. Primer balance must be determined by what you are shooting, NEVER by what you can buy. If they are not right, don't buy the things.

[M4bushy]

Exactly, you are correct.
But ignore the spike for a second. Primer pressure alone can move out a boolit before good ignition. That changes air space from shot to shot.
Tests have shown the tiny cases can not absorb the pressure from the primer. The ACP works better with a standard SP primer.
I refuse to use a mag primer in the .44 mag and .45 Colt even with 296.
With a rifle, LP mag primers can work fine depending on case size and powders. Large cases need LR and larger yet need LR mag primers. Primers of all kinds can take a lot of pressure, I have taken LP mags to over 50,000 psi without making them flat. That is not the reason, it is flame front, the amount of heat, primer pressure, powder choice and the size of the case.
Primer thickness can be an issue with very strong mainsprings or wrong shaped pins that can puncture them. Primers for an AK must be very tough or the gun will slam fire. Floating pins need very hard primers.
Beside the point anyway. Too much primer pressure in tiny brass is wrong just like not enough in large cases. Primer balance must be determined by what you are shooting, NEVER by what you can buy. If they are not right, don't buy the things.

I agree this is an issue with the slower powders ie 2400 but i haven't seen any data of that happening with faster pistol powders. Except for the sse claims with powders such as Tightgroup with tiny charges in karge cases.

[44man]

I agree this is an issue with the slower powders ie 2400 but i haven't seen any data of that happening with faster pistol powders. Except for the sse claims with powders such as Tightgroup with tiny charges in karge cases.
Yes, boolit punch out from the primer does happen with fast powders too but it is masked by quick pressure rise.
It is crazy. Think of a few gr. of Bullseye in a huge case. It is all over the place with no gr. close together. Now you need FIRE. Just keep primer pressure down.
What happens in a powder column with a primer? I don't profess to know. What is the difference in squirting flame and pressure through the column versus lighting it at the start and getting a progressive burn?
Most of my accuracy comes from a progressive burn, light the powder at the flash hole and let it go. Don't blast all the way through the powder charge. Do not reach the boolit base with pressure before the powder lights off.
Do I make any sense?