Regarding primers

[smorris.357mag]

Are magnum small pistol primers interchangeable with small rifle primers? For several years I have loaded only .38 special and .357 magnum, but I have recently picked up dies and brass for .30 Carbine.
I have a few magnum small pistol primers, but no small rifle primers. The reloading manuals call for small rifle primers. Reloader friends have said they are interchangeable, but I am reluctant to try it without some more seasoned opinions. In my experience with other disciplines, similar size and shape are not necessarily evidence that the internals are identical.

 

[Blue68f100]

In short NO, since there is a pressure difference between rifle and pistols. Pistol primers are limited to around 35k psi where rifle primers are 65k. So if your shooting a low pressure round that calls for Rem 6 1/2 ( designed for the hornet) they work perfectly in handguns. The biggest problem is some handguns don't have enough energy to set off rifle primers.

If you don't go wild the 30 carbine can use the Mag Pistol primers with out issues.

 

[smorris.357mag]

That makes sense if I were going the other way around and using small pistol primers in rifle cases. My specific question relates to using magnum pistol primers in .30 Carbine cases - for a .30 Carbine rifle. Both .38/.357 magnum and .30 Carbine cartridges are used in both rifle and pistol. If I am going to blow the pistol primer out of the .30 Carbine case, that is one issue. If the pistol primer won't ignite the powder in a .30 Carbine case, that is something else altogether. I wouldn't even be asking this if there were any small rifle primers available anywhere around where I live.

 

[fxvr5]

FYI, the max SAAMI pressures are listed below:

30 Carbine = 40,000 psi
223 Remington = 55,000 psi

357 Magnum = 35,000 psi
9mm Luger +P = 38,500 psi
357 SIG = 40,000 psi

 

[2ndtimer]

A lot of people use small rifle primers in pistol cartridges. I have even read (from somewhat reliable sources) that CCI-550 small pistol magnum primers are identical with CCI-400 small rifle standard primers. If I were in your shoes, I would go ahead and load 5 rounds of .30 carbine with your magnum pistol primers and STARTING powder charges and closely examine the primers on the fired cases. It may be that the firing pin on the.30 carbine will pierce the possibly thinner pistol primers, in which case, I would end the experiment. But if they shoot okay and primers look okay, then proceed. According to Hodgdon’s loading data for the .30 carbine, their listed loads generate less pressure than their loads for .357 Magnum, so unless there is something about the firing pin in your particular carbine, you should be fine with magnum pistol primers, especially if they are CCI-550’s. Only one way to be sure, is to try them and see. The other alternative is to try to trade your magnum pistol primers for some small rifle primers. Let us know how it works out. (I am curious, and I would bet a dollar that if you have CCI-550’s, they will work fine.)

 

[fxvr5]

I have even read (from somewhat reliable sources) that CCI-550 small pistol magnum primers are identical with CCI-400 small rifle standard primers.

That is not true and has been debunked.

https://thefiringline.com/forums/showthread.php?p=6811870#post6811870

Update on CCI 550 primers and CCI 400 primers being the same. They are not.

See posts number 7 and 14.

The ONLY reliable sources are the product manufacturers. If you didn't get it directly from them, don't believe it until you do get it directly from them.

 

[FROGO207]

I go the other way. I use small rifle primers instead of SPP everywhere I can. Some handguns with weak firing pin springs will not fire them and for those I use SPP. For those pressures listed you might be OK if you work up cautiously. I have never tried what you are thinking of so will not reccomend it. Let us know if things work out or not. YMMV

 

[.38 Special]

<edit> Eek. Wrong link. Stand by while I try to find the right article.

The short version is that small pistol primers probably will be fine in the .30 carbine.

 

[blue32]

Speer 14th ed. P.33, paragraph 5: "Small pistol primer pockets are the same depth as small rifle pockets." My concern would be the thinner cup being prone to piercing. On the other hand, I load 32-20 with SPP and SRP depending on the powder and load with no problems. If it were me, I would at the very least prime some empty cases and see if the cups withstand the force of the firing pin before proceeding. Ultimately its up to you but I would err on caution.

 

[Bfh_auto]

FYI, the max SAAMI pressures are listed below:

30 Carbine = 40,000 psi
223 Remington = 55,000 psi

357 Magnum = 35,000 psi
9mm Luger +P = 38,500 psi
357 SIG = 40,000 psi

Wasn't the old 357 pressure somewhere around 46000 psi? It used mag primers back then without issue.
The 30 carbine is well under that.
I find it strange that 30 carbine, 22 hornet, and 32-20 even dream of needing a srp.
I'm not the one spending all the money to create tested data though...

 

[fxvr5]

Wasn't the old 357 pressure somewhere around 46000 psi? It used mag primers back then without issue.
The 30 carbine is well under that.
I find it strange that 30 carbine, 22 hornet, and 32-20 even dream of needing a srp.

According to the SAAMI publication, the CUP pressure for 357 magnum is 45,000 CUP. But CUP and psi are different measurements.

The 22 Hornet has a SAAMI pressure limit of 49,000 psi.
The 32-20 has a pressure limit of 16,000 CUP. It does not have a psi pressure established in the SAAMI publication I have.

 

[JJFitch]

Here is a link to every thing you ever wanted to know about primers! It is long, complete and worth the read!

https://www.sksboards.com/smf/index.php?topic=56422.msg646510#msg646510

This should be considered for a "sticky" since the "Primer" question comes up several times a week here and elsewhere!

Smiles,

 

[mrawesome22-250]

Just some of my recent personal experiences with new manufacture CCI 550 primers.

I've loaded and shot close to 1000 CCI 550's loaded with a max charge of BLC2 in LC 5.56 brass topped with 55 and 62gr fmj.

All have went bang. None have shown any indication of primer failure whatsoever.

These have all been shot in a newly built AR with a NATO chamber.

 

[CQB45ACP]

Here is a link to every thing you ever wanted to know about primers! It is long, complete and worth the read!

https://www.sksboards.com/smf/index.php?topic=56422.msg646510#msg646510

This should be considered for a "sticky" since the "Primer" question comes up several times a week here and elsewhere!

Smiles,

Wow! That’s good stuff.

 

[2ndtimer]

Wow! That’s good stuff.

And from that “good stuff” in his second post on the original thread:

“NOTE 1: According to Speer/CCI Technical Services - Both the CCI 550 Small Pistol Magnum and CCI 400 Small Rifle primers are identical in size. Both primers use the same cup metal and share the same cup thickness. Both primers use the same primer compound formula and same amount of primer compound. They can be used interchangeably.”

Granted Frisco Pete’s lengthy posts regarding primers was from 10 years ago, but it is certainly possible that at one time they were interchangeable, and perhaps not so much today. Given the OP’s original query, if I were in his shoes, with primer availability what it is today, I would give them a try and work up carefully.

 

[fxvr5]

“NOTE 1: According to Speer/CCI Technical Services - Both the CCI 550 Small Pistol Magnum and CCI 400 Small Rifle primers are identical in size. Both primers use the same cup metal and share the same cup thickness. Both primers use the same primer compound formula and same amount of primer compound. They can be used interchangeably.”

Granted Frisco Pete’s lengthy posts regarding primers was from 10 years ago, but it is certainly possible that at one time they were interchangeable, and perhaps not so much today. Given the OP’s original query, if I were in his shoes, with primer availability what it is today, I would give them a try and work up carefully.

It is KNOWN that the two primers are not the same today. See the link in post #6 from 2020.

 

[2ndtimer]

It is KNOWN that the two primers are not the same today. See the link in post #6 from 2020.

Didn’t say they were the same today (nor yesterday if you read my post). But if I couldn’t locate any small rifle primers, and had some CCI-550’s and wanted to load for a .30 Carbine, I would give them a try.
And mrawesome22-250 shared that he has loaded close to a thousand .223/5.56 rounds using the CCI-550 primers without issue (post #13), and since the .223 lists higher pressures than .30 Carbine, it should be a relatively low risk experiment. Or, the OP might just fork over the current $100-$250 that buyers are paying per thousand on gunbroker.com and acquire some small rifle primers. I guess the only other option is to wait and hope primers become widely available again for less than $50 per K.