Lets talk about Primers?

[Jmac00]

first off, why is one primer better than another in the same cartridge?

How does a primer react to powder or different powders, Flake, round, ect, ect

does the powder hole affect the the speed at which it burns?

 

[MilesTeg]

I don't think the primer plays as huge of a role in the cartridge as internet lore says. Let's face it this is the one aspect in the process we can't really tweak. The only thing we can do is switch brands.

For one brand working better than the other. I think most if that is actually priming the brass no how it performs in the load. The only way one is better than the other is standard primer versus match primer.

The name of the game in precision reloading is consistancy. I'll give it a maybe some brands are more constant than others. I think there are too many variables for most people to notice. This consistancy is why some people deburr the flash hole to help ensure a more consistent ignition.

Another thing to note is your reloading is your building a system. Sometimes good/great components don't work in your system. It doesn't mean one is better than the other.

For different primers working with different powders maybe the different primers have different flashes, In size heat and intensity. But I think this variation is so small most people wouldn't be able to notice. Plus with a proper work up this should be a moot point.

 

[Tisto]

Primers are indeed different. One brand of primer may produce fabulous results in a given cartridge and rifle combination, while a different brand ( and sometimes even a different lot number of the same brand ) may not produce those same results with all else being the same.

I have a custom made rifle chambered in 6mmPPC. The 6 PPC is argueably one of the most accurate cartridges ever developed. Having spent many years developing a match winning load, I will tell you that primers do in fact make a difference.

Now, will MOST people ever notice a difference ? No, i don't think so, but there are other factors to consider. The kernal of flame may vary in temperature, burn time and intensity a great deal from one brand to the next, possibly producing a large change in chamber pressures and velocity. Some of the older reloading manuals went into this topic at length. I can't recall a recent manual that I own digging into it so deeply.

Bottom line is, if you're looking for a single 30 caliber hole that 20 6mm bullets have passed through, primers matter. So does EVERY other component at that level. If you are stoked that you put 5 rounds inside an inch with your favorite deer gun, then the difference is probably lost on you. You can probably switch between brands freely, just watch for signs of pressure.

 

[Exonautic]

Primers are indeed different. One brand of primer may produce fabulous results in a given cartridge and rifle combination, while a different brand ( and sometimes even a different lot number of the same brand ) may not produce those same results with all else being the same.

I have a custom made rifle chambered in 6mmPPC. The 6 PPC is argueably one of the most accurate cartridges ever developed. Having spent many years developing a match winning load, I will tell you that primers do in fact make a difference.

Now, will MOST people ever notice a difference ? No, i don't think so, but there are other factors to consider. The kernal of flame may vary in temperature, burn time and intensity a great deal from one brand to the next, possibly producing a large change in chamber pressures and velocity. Some of the older reloading manuals went into this topic at length. I can't recall a recent manual that I own digging into it so deeply.

Bottom line is, if you're looking for a single 30 caliber hole that 20 6mm bullets have passed through, primers matter. So does EVERY other component at that level. If you are stoked that you put 5 rounds inside an inch with your favorite deer gun, then the difference is probably lost on you. You can probably switch between brands freely, just watch for signs of pressure.

since you seem to have experience with this, maybe you can share your opinion on using magnum primers in lieu of standard primers and whether or not that change will produce a more consistent burn rate of all the powder.

 

[Tisto]

NEVER casually replace standard primers with magnum primers. Ever. Magnum primers, as a general rule burn hotter, and for a longer time than standard. This is to more uniformly ignite the massive quantities of powder in a magnum cartridge.

Imagine, if you will, some powder laid out on a concrete floor in a line. Light that powder at one end. It burns from where it was ignited to the end in a nice, smooth, flowing motion. When it's consumed, it goes out.

Now, light the same powder with a propane torch all at once. You still consumed the powder, and it still produced the same amount of energy, but the reaction was not smooth. It was much more instantaneous.

The burning of a propellant inside a cartridge and the bore of the gun should be seen the same way. Ideally, your powder should be ignited such that it burns and consumes itself just as the bullet departs the bore, producing nice smooth pressures that don't have wild spikes, and don't drop dramatically before the bullet departs.

The use of a magnum primer in place of a standard one ( all other factors remaining unchanged ) will ignite the powder in such a way as to produce a huge initial spike in pressure, usually followed by a dramatic drop because the powder has been consumed too quickly.

It has long been believed that a smaller flash jole in the brass is more conducive to accuracy. I tend to agree with this, but I believe that uniformity is at least as much a factor.

If you're trying to ignite powder in a severely over-bored cartridge ( for example, the .300 Remington Ultra-Mag ), then you indeed need a magnum primer. Otherwise, stick to what the book calls for. Watch for signs of pressure at every turn, and stop as soon as they are noticed. Books are all different, just as your rifle and load is different, but trying to squeeze an extra 100 fps out of your load isn't worth the damage you may do to your gun or yourself. "HOT" loads seldom produce great accuracy, and often produce "ACCIDENTS".

 

[Acer-m14]

@Tisto i reload for a .270 win .. one book and its has load data from a famous .270 win hunter .. i can't recall name with out a search or go find the book ..
it lists min to max . then a foot note .. lets just say since i don't have the info actual data to quote ..
min 2600 fps .. max 3100 fps .. then the foot note .. best hunting load .. 3300 fps compressed load . just does not make sense to me LOL ..

i only hunt with a at most a 300 yd shot .. i load to 2900 , saves powder

 

[Tisto]

A quick look at 4 different (3 current and 1 old ) reloading book shows none of them using a magnum primer in any load.

The .270 Win was a .30-06 necked down. It is an efficient cartridge known for flat trajectories and inherrent accuracy. Most common loads use bullets ranging from roughly 130 gr. to 150 gr. Light for caliber loads go as low as 100 gr.

I'm curious as to what exactly your load consists of- powder type and charge, and bullet brand, style and weight, seating deapth, OAL, etc. Care to share ?

As far as the author's pet load being 200 fps above the max load listed, that may be an actual chronograph reading, from his particular gun. If you're trying to duplicate his load, do so carefully, working up to it in small increments.

Do you have access to a reliable chronograph ?

Keep in mind that barrel length has an effect on both pressures and velocities as well.

 

[Jmac00]

I'm glad I started this thread, this is very interesting, Thanks for everyone's input.

 

[squib]

In my opinion only people who are "handloaders" of metallic cartridges will notice a measurable difference in similar primers.

 

[Tisto]

Sorry, I feel as though I should clarify my last post. When I said that none of the four books I looked at this morning showed magnum primers in any load listed, I was referring to the loads listed for the .270 Winchester cartridge only.

Magnum cartridges require the use of magnum primers in most cases.

 

[Uninformed and Compliant]

One other primer type that I occasionally get asked about -
CCI #41 vs a regular SR?

The 41 is a harder metal to prevent slam fire, but how likely is that to actually happen IRL?

 

[Acer-m14]

A quick look at 4 different (3 current and 1 old ) reloading book shows none of them using a magnum primer in any load.

The .270 Win was a .30-06 necked down. It is an efficient cartridge known for flat trajectories and inherrent accuracy. Most common loads use bullets ranging from roughly 130 gr. to 150 gr. Light for caliber loads go as low as 100 gr.

I'm curious as to what exactly your load consists of- powder type and charge, and bullet brand, style and weight, seating deapth, OAL, etc. Care to share ?

As far as the author's pet load being 200 fps above the max load listed, that may be an actual chronograph reading, from his particular gun. If you're trying to duplicate his load, do so carefully, working up to it in small increments.

Do you have access to a reliable chronograph ?

Keep in mind that barrel length has an effect on both pressures and velocities as well.

yes i have a chrono , and the 270 loads i do from the book i have .. i load to the 2800 to 2900 fps range .. i'm just hunting dogs ( deer ) lol.
and the load data from the book is pretty spot on with the chron .. not sure the brand of bullet but 130gr SP .. might be a BTSP too

I'll be in the loading room this weekend and can get more data ..

Jack O'Connor's .270 Winchester load is what i was thinking about ..

 

[Acer-m14]

The 41 is a harder metal to prevent slam fire, but how likely is that to actually happen IRL?

ever seen the safety on a Mosin .. LOL .. i'm not sure it will actually fire if your fingers slip .. but man it looks and feels sketchy putting it on safe LOL ..

 

[Acer-m14]

this may tie into the primer issue in a way .. but a cool vid .. but i think it just goes back to chamber pressure .. can a short barrel hold the pressure to get all the powder to burn in a few milli seconds before the bullet leaves the barrel .. ie a 300 BO with a 10 inch pistol barrel ...

Magnum cartridges require the use of magnum primers in most cases.

so if all you have is regular primers .. less powder could be burnt .. less chamber pressure .. just make a dope chart on how that shoots

putting a mag primer in a 9mm might be a bad idea

 

[Tisto]

The use of a standard primer where a magnum primer is called for can be just as dangerous, as a hangfire may occur. Worse yet, the larger cartridges are more prone to this. Admittedly, hangfires are rare, but they are at the least unpleasant and at worst deadly. Avoid problems by following recognized reloading manuals published by reputable companies carefully.

 

[Jmac00]

Sorry, I feel as though I should clarify my last post. When I said that none of the four books I looked at this morning showed magnum primers in any load listed, I was referring to the loads listed for the .270 Winchester cartridge only.

Magnum cartridges require the use of magnum primers in most cases.

so, why wouldn't a Large Pistol primer work?

 

[MilesTeg]

so, why wouldn't a Large Pistol primer work?

Pistol and rifle primers big difference is the cup thickness.

 

[Tisto]

It's true, the CCI 41 has a harder cup to help prevent slam fires. Other than that, I'm not aware of any other difference from the standard CCI small rifle primer. The military uses them in their ammunition to prevent accidental discharges. Keep in mind that military weapons that are used in battle wear more and are frequently not maintained as well as they should be. Cleaning your rifle while someone is shooting at you is frowned upon by the other members of your squad. Slam fires happen, but not frequently. The harder cup helps lessen that occurance.


The .300 AAC BLACKOUT is an interesting cartridge. A shortened and necked up .223 Rem case, it holds a relatively small amount of powder. Given the capacity of the case, the diameter of the bore, and the relatively fast burning powder used in it, most of the loads burn all the powder inside a 14" barrel. From what I've read, 10" to 14" barrels are the optimum length for this cartridge. Longer than 16" barrels start to show a decrease in velocities because the powder is used before the bullet travels that far. The .300 BLK is well suited for a supressor because of this. A can may be attached to the end of a 10" barrel and be quite effective while still remaining short enough for CQB.

 

[Tisto]

Miles Teg is correct. The cups are very different for pistol and rifle primers. However, there is a difference in the priming mixture as well. I have accidentally used small pistol primers where small rifle primers were supposed to be used. There were no accidents ( luckily ) but i noticed signs of pressure where that load had not shown any sign of pressure previously. The old .222 Rem that this happened in was not damaged, but after I figured out what had happened, I pulled the remaining lot of ammunition to be on the safe side. Sometimes lessons are learned without an accident.

 

[squib]

this may tie into the primer issue in a way .. but a cool vid .. but i think it just goes back to chamber pressure .. can a short barrel hold the pressure to get all the powder to burn in a few milli seconds before the bullet leaves the barrel .. ie a 300 BO with a 10 inch pistol barrel ...



so if all you have is regular primers .. less powder could be burnt .. less chamber pressure .. just make a dope chart on how that shoots

putting a mag primer in a 9mm might be a bad idea

Shotshell primers are another can of worms. Each brand 209 primer has a different pressure curve.

 

[Tisto]

Squib is absolutely correct on that one. Shotshell primers create a very large deviation in pressures from one brand to another. Worse yet, signs of excessive pressure are very hard to discern from a plastic shotshell. Again, stay within the boundaries set forth in an established publication.

Whether metallic reloading or shotshell reloading, using "Cousin Eddie's best friend's recipe" can spell disaster.

 

[CaliberPlus]

Shotshell primers are another can of worms. Each brand 209 primer has a different pressure curve.

I asked dh about this yesterday. I think we speak different languages. I don't want to highjack this thread so I will start a new one. This has been a helpful thread.