Primer power?

[Tu_S]

I am in the unfortunate position of not having any small pistol primers available, so set out to duplicate my standard velocities by using small rifle primers. I loaded with both pistol and rifle primers and consistently found that I gained around 50 fps with small rifle primers. I can now confidently load my 38s using small rifle primers until the market resupplies SPPs. This equated to about a 7% increase in velocities for the loads I tested. Another data point I noticed is that the small rifle primer recorded a lower standard deviation than small pistol primers, which is certainly a good thing.

Owning a chronograph is essential for this type of load development and I would not hesitate to try primer substitution by loading both primers and check velocities at the range. Start out loading about 10% less powder and check the magnum primer velocities, comparing them to your standard primer load velocities. Load rounds in groups of 5, slowly stepping up to standard amounts of powder with magnum primers and stop testing when you reach the proper velocities to match those using standard rifle primers. Pull the bullets on the rest. Same testing can be done with military primers and you can develop loads that match velocities and are perfectly safe substituting the different primers.

Curious to know, what powder did you use for this test?

Among the theories I have heard, if you're using a fast burning propellant like 700-x, you won't see a big change moving from a standard to magnum primer since even though it is a magnum (or in your case rifle,) the powder burns so fast it doesn't matter. Now if you go to something slower like CFE Pistol, initiating more of the charge when it starts will cause the rest of it to burn up faster than it normally would, and you would see an increase in pressure.

I have to say I have no idea if this is true or not. I guess I'm over educated enough to make myself dangerous and can see how it makes sense, but am also old enough to know I don't know everything and have no problem admitting it.

So, I guess I'm asking to either get another data point to say it's a viable theory in the case of you using something on the slow side, or have more information to bust it.

 

[alwslate]

It seems that many are over thinking the use of primers with the typical fearful “what if” approach. From my own considerable primer comparisons I can offer a couple of examples of primer effect. 5.7 grs of Bullseye, 158 gr cast SWC, Win SP primer, around 1040 FPS in a 4” model 28 with extreme spread of about 60 FPS. Same with Win SPM primer bumped velocity about 10 FPS and lowered ES to less than 30 FPS. Change the load to 14.2 grs of 2400 and the difference in velocity is over 100 FPS and again ES is cut to less than half. The real question seems to be if you can stock up on whatever primers you want why would you buy anything but magnum primers? Win SR and SPM primers are virtually the same.

 

[Tu_S]

It seems that many are over thinking the use of primers with the typical fearful “what if” approach. From my own considerable primer comparisons I can offer a couple of examples of primer effect. 5.7 grs of Bullseye, 158 gr cast SWC, Win SP primer, around 1040 FPS in a 4” model 28 with extreme spread of about 60 FPS. Same with Win SPM primer bumped velocity about 10 FPS and lowered ES to less than 30 FPS. Change the load to 14.2 grs of 2400 and the difference in velocity is over 100 FPS and again ES is cut to less than half. The real question seems to be if you can stock up on whatever primers you want why would you buy anything but magnum primers? Win SR and SPM primers are virtually the same.

From my post #21 on this thread, with Bullseye being one of the faster burning, and 2400 slower, it fits the theory I was told.

As I said, I'm just looking for good data on this, with test cases where the only thing that changed is the primer.

FWIW, I've been fortunate enough to have not run out of primers during the current shortage and have not had to experiment, although I was down to 200 CCI #300's at one point. When it comes down to it, if I did run out of large pistol primers, I'd just be shooting the guns that use what I still have until I could restock.

 

[ArchAngelCD]

"The CCI #34 primer is a Magnum strength primer..."

I would REALLY like for you to explain what the precise definition of "Magnum Strength Primer" is.

....My concern is that many seem to conflate the meaning of "Magnum" to suggest that the word on a primer box indicates that it is somehow supercharged in its ballistic properties when that does not appear to be the case at all, the real purpose being to indicate that it will withstand the higher chamber pressures usually associated with Magnum cartridges without failure.

From what I have read a magnum primer will burn slightly hotter and slightly longer than a standard primer. Nowhere did I ever say a word on a box would "supercharge" anything.

Below is a link with a good article about primers from Shooting Times.
https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

 

[glowe]

Curious to know, what powder did you use for this test? . . .

The only thing I changed was the primer. Loads were all done with the same amount of Trail Boss, the same bullet, and the same gun. I always use a 6" gun when testing, assuming that any shorter barrel will see lower velocity. Trail Boss is #22 of #146 on my chart, so on the upper end of the spectrum.

Lots of speculation on this issue out there and as many opinions as there are people. That is the very reason why I always work up test loads when trying anything new. You will not find any information out there from primer manufacturers on substituting primers due to the liability exposure is some screws up reloading.

 

[41 mag Dave]

A magnum primer will have a longer and wider flame than a standard primer. The difference is usually only seen in powders that are very slow burning for the cartridge, also they can give better ignition with ball powders.

The difference in ignition can be large. Federal 215 Large Rifle Magnum are the only primer that give the best accuracy in my 300 Weatherby. The 454 Casull needs a Small Pistol Magnum(Small Rifle) primer.
I have had pressure decreases and lower rates of fire in a 9mm sub gun when using Small Rifle Primers. The primer was pushing the bullet free of the case and the powder was burning when the bullet was in the chamber throat. I happened in milliseconds but was very close to and obstructed bore.

There is no secret about primers, the manufacturers have all the data out and available on primers.

 

[Tu_S]

The only thing I changed was the primer. Loads were all done with the same amount of Trail Boss, the same bullet, and the same gun. I always use a 6" gun when testing, assuming that any shorter barrel will see lower velocity. Trail Boss is #22 of #146 on my chart, so on the upper end of the spectrum.

Lots of speculation on this issue out there and as many opinions as there are people. That is the very reason why I always work up test loads when trying anything new. You will not find any information out there from primer manufacturers on substituting primers due to the liability exposure is some screws up reloading.

This does actually support the theory on the relationship between powder burn rates and primers, but is a long way from proving it.

From this and the other post we have 3 propellants, Bullseye, Trail Boss, and 2400, which according to my burn rate chart are ranked as 13, 23, and 54, that gave 10, 50, and 100 FPS deltas when switching to a "hotter" primer.

While there are far too many other variables to prove the theory that switching to a magnum primer is safe(er) when using a faster powder, it does support it.

What this also supports are the differing opinions on if it is safe or not to substitute a magnum for a standard primer. Given all the contradicting views, it seems like the individual experiences and conclusions could all be plausible based on the specifics of what was tested.

 

[STORMINORMAN]

"On this, the 3rd planet from the Sun, most carbon-based life forms operate on a bell-shaped curve..."

This, also, apparently applies to reloaders as well...? Some live "by the (a?) Book". Personally I have seen enough errors in print to be aware that further investigation or research may be necessary.

Cheers!

P.S. IMHO, when one is loading "on the upper edge"(?) almost all the variables (i.e., powder, primer, crimp, OAL, bullet design & hardness, etc.), even in small increments can potentially have a less than desirable effect: and that is why I don't go there...!

Elmer Keith I am not.

Mid-book loads are that ol' "horse of a different color": you can safely work up a load with different primers as well.

 

[alwslate]

What people fail to understand about loading handgun vs centerfire rifles is that maximum loads for rifles may be close to maximum working pressures while handgun loads are not. A maximum load for the .308 Winchester may be at 62,000 psi, a maximum load for the .357 will be a bit less than the top industry standard of 35,000 psi, the same as std pressure 9mm. NO substitution of primers with any handgun load is going to result in a dangerous load period folks. As to slow powders it is just about impossible to get enough 2400 in a case and still seat a 158 gr bullet and actually reach 35,000 psi with any primer. People will shoot factory 9mm ammo in their J frames all day long but are terrified about loading a .357 magnum K,L or N frame revolver to anywhere near 9mm pressure levels??? All of this phobia about primers is ridiculous.

 

[BigBill]

My 30-06 using a magnum primer with IMR 4350 powder I think it’s a tad hot maybe old age is creeping up on me. I’ll check the load. I might pull the fmj bullets and recycle some powder, lessen the charge.

The 1972 western auto revelation mossberg 30-06 bought new in ‘72 shoots 5 shot nickle sized groups to this day at 100 yds benchrested.

For 38 spec it’s small primers with unique for leadcast. For 357 it’s small magnum primers 2400 for jacketed. I use unique for large pistol primers 44 leadcast and 2400 with win large pistol primers jacketed. I have all the correct primers instock.

 

[ArchAngelCD]

My 30-06 using a magnum primer with IMR 4350 powder I think it’s a tad hot maybe old age is creeping up on me. I’ll check the load. I might pull the fmj bullets and recycle some powder, lessen the charge.

The 1972 western auto revelation mossberg 30-06 bought new in ‘72 shoots 5 shot nickle sized groups to this day at 100 yds benchrested.

I load a lot of 30-06 ammo for sure. Most times I use a CCI-200 primer or a Winchester LRP. When I bought a box of reloading components at an auction I got several thousand CCI BR-2 primers. (benchrest primers) I figured I would give them a try in my 30-06 hunting ammo. Well, they seem work well and since they are considered a higher quality primer I now load my hunting ammo with them. I have them so I use them lol.

M1 Garand ammo is a topic for another thread.

 

[BLUEDOT37]

Do you read what you type?

People will shoot factory 9mm ammo in their J frames all day long but are terrified about loading a .357 magnum K,L or N frame revolver to anywhere near 9mm pressure levels???

Such a misleading generalization.

You're inferring that all "factory 9mm ammo" is at 35K psi (SAAMI max for standard 9x19 ammo), which of course they are NOT.

You're also implying that a full power 9x19, 35K psi load, is as powerful as a full power .357 Magnum 35K psi load is, which it is NOT.

A .357 Magnum case has twice the case capacity of a 9x19 case (13.3gr -vs- 26.7gr./H²O).

Both filled with a max load of their slowest powder & using the same weight bullet (125gr), the .357 produces way more power.

Should they be "terrified" of the extra power (nearly double the muzzle energy)?

No, but most will opt for the watered down power of "white box" 9x19, or 38 Special power, if given the choice, but for you to mock people who can actually tell the difference between full power loads in each cartridge??

.

 

[ReloadforFun]

Power (energy) and pressure are not the same thing.

 

[alwslate]

Well BLUEDOT you continue to amaze me with your inability to comprehend the written word.You completely fail to understand my post. Many handloaders fear loading to anything near industry std top pressures in the .38 spl and .357 mag. It has nothing to do with relative power between the .357 and 9mm which have the same industry std maximum 35,000 psi. And how is it in your infinite wisdom that you know factory 9mm isn’t even close to 35,000 psi. Most published handloads for the .38 spl will be well below the 17,000 psi level for std pressure and most published loads for the .357 will be somewhat below the 35,000 psi level. A simple primer switch isn’t going to result in sending pressure to the catastrophic level.

 

[STORMINORMAN]

I must be missing something (or, an entire post, maybe?)...

 

[stansdds]

Kind of thinking this thread has run its course.

 

[BLUEDOT37]

Well BLUEDOT you continue to amaze me with your inability to comprehend the written word.You completely fail to understand my post. Many handloaders fear loading to anything near industry std top pressures in the .38 spl and .357 mag. It has nothing to do with relative power between the .357 and 9mm which have the same industry std maximum 35,000 psi. And how is it in your infinite wisdom that you know factory 9mm isn’t even close to 35,000 psi. Most published handloads for the .38 spl will be well below the 17,000 psi level for std pressure and most published loads for the .357 will be somewhat below the 35,000 psi level. A simple primer switch isn’t going to result in sending pressure to the catastrophic level.

How cute!

With all of your misdirection & deflection you ignored telling us how YOU KNOW why people are "terrified" to load their 357s to full load capability?

And I'm not going down that same road about primers with you.

You've already told us in another thread that you know better than the manufacturers because of your vast experience.

Feel free to have the last word, which I know you like.

.

 

[alwslate]

How cute!

With all of your misdirection & deflection you ignored telling us how YOU KNOW why people are "terrified" to load their 357s to full load capability?

And I'm not going down that same road about primers with you.

You've already told us in another thread that you know better than the manufacturers because of your vast experience.

Feel free to have the last word, which I know you like.

.

I have yet to see you do anything except attack my posts. No real contribution of any kind from you. No chronograph records, no loads or demonstration of true understanding of the contradictions in loading manuals. You are one of those people who are unable to really contribute to a topic and tries to establish his “expertise” by just attacking the real data of others.

 

[ArchAngelCD]

It's too bad because I was enjoying this thread like many others but I'm closing it because it's going downhill quickly. If you want to bicker take it to email or a PM but don't involve us and the forum!