DOES ANY ONE KNOW

[williamlayton]

What critera do bullet makers take into consideration when chooseing primers.
What are the critical issues.
I am not talking about makes of primers.
Blessings

[Bigeasy]

If I were to guess, in loaded ammo, I would think primer burn rate being applicable to the propellant type and volume, cup thickness being proper for application, consistency for accuracy would be some of the considerations.
 
Larry

[Land_Owner]

Most Mfg's indicate the primer of choice in their reloading manuals for the bullet/powder combination under consideration.  I have seen some previous printed material in reference to Standard vs. Magnum primer use.  I believe there is a fast/slow bullet velocity as well as a fast/slow powder relationship for magnum vs. standard.

[anachronism]

Read your reloading manual, the powder manufacturers manuals are better than the bullet makers books for this  because they pressure test everything, and openly tell you which primers to use. Some primers won't ignite certain powders correctly under certain circumstances. Winchester large pistol primers are a source of confusion for many because they're hotter than some other brands. They list their LP primers as being for "standard and magnum loads". But, Winchester also sells powders (through Hodgdons), and loading data is readily available. There really is no need to guess, the information is available.

[williamlayton]

I do communicate poorly.
If a primer is used to ignite a powder source--what is the criteria/critical issue for using one or the other.
I understand pressures---and I am not argueing to just use any primer for there are obviously some differences--but why are there differences?
Blessings

[anachronism]

The type of powder used has a lot to do with it. Ball powders require a hotter primer, according to Winchester. The coatings used on the various powders to fine tune the burning rate seem to be a deciding factor as well. Stick powders have more surface area per granule, which would seem to me be a factor as well. Unfortunately, information regarding primer selection isn't given freely by the powder manufacturers, they just tell use what perform the best in their pressure guns. Even if we were given the exact information, it's unlikely we would be able to fine tune primer selection without going insane, due the the manufacturing tolerances of each component. So they just make recommendations that are adequate for the vast majority of applications, with safety the primary consideration, and let us experiment on our own to fine tune the load to out specific needs/wants

[BBF]

I believe it is mostly a financial consideration.

[necchi]

anachronism has touched on it, an I'll add some, it takes a full chapter to explain primers.
It's about the surface area of the powder in the case, the size of the case and the amount of powder in the case.
That's why load manuals can be a bit deceiving, they chose a primer for the load and use it with all the powders tested so they only change one variable, powder type and charge for us average guys to review.
 
 Magnum primers are not "hotter" than standard primers. The make up of the chemicals used in magnum primers has a higher metal content like aluminum that will throw the burning primer charge deeper or further into the case to ignite a powder along the full length of the case instead of from just the end.
 The powder burn rate and surface area now comes into play. While the pressure developed can/will be within safe limits with either primer, powder burned slowly (ignited from the end) will spike at a different time in the sequance than the same powder ignited along it's full length in the case.
 So this is why a primer choice will change the entire load characteristics and accuracy, the powder charge might need to be different with a primer choice. The combination of powder, primer, case size and shape, and bullet weight all factor into when is the best pressure spike in the firing sequance.
 
Here's some really good reading and study of primer stuff by German Salazar, ya gotta go back to his "Articals Index" to link to small primers; http://riflemansjournal.blogspot.com/2009/06/primers-large-rifle-primer-study.html
 
 
 I gotta add that accuracy can be found with most primer/powder combinations, people do it all the time. I know some that will use only Mag primers just to simplify purchase issues, others start with a given primer for whatever reason and simply consider those the best because they work for them.
 I'm not one to worry too much about primer choice, but I have found a differance in the application to different guns. Tried Rem 9 1/2 in a buddies 308 AR, and found Win Mags to be the ticket for that gun. Then theres the size and hardness of the cup,,,

[Larry Gibson]

I do communicate poorly.
If a primer is used to ignite a powder source--what is the criteria/critical issue for using one or the other.
I understand pressures---and I am not argueing to just use any primer for there are obviously some differences--but why are there differences?
Blessings

Type of powder (ball vs extruded vs flake and amount/type of deterent on powder) being used, quanity of that powder used in a specific cartridge (standard primers with 4831 in standard cases vs magnum primers with the same 4831 in magnum capacity cases) and consistency of ignition (Minimal extreme spread and standard deviations for 10 shot test strings as per SAAMI) over a wide range of temperature condidtions (as per SAAMI it is well below freezing to well over 100 degrees).
Larry Gibson
 

[williamlayton]

Now I am getting the picture---thanks for the link---my head hurts.
Again--it was just an understanding issue with me as I don't experiment and follow directions.
I hate to assume but going by what I am learning---and it is a big but, because I am assuming that there are simular parallels between rifles and hadguns & the results of primers.
I digress--The effect of  using larger primers would indicate a need for reduction of volumn--which could effect/affect accuracy. The thought seems to be that the best accuracy seems to come with powders that fill the case and the use of hotter (softer) primers and reduced powder charges can reduce accuracy.
This makes since to me as I have been told that it is better--for accuracy--to use powders that allow full case loads or close as possible.
Am I reading this correctly.
You guys did good---as usual.
Blessings

[Catfish]

When you start to think you know all about primers, they are going to fool you. I once did some extencive trsting of primers. I used 4 different rifles in 4 different cal`s. I would load up 3 rounds and cahnge only the primer. I had one round that with 4 different primers, some mag. some standard the extreem spread was 7 after 12 rounds with 4 different primers. I had 1 load that was showing presure signs with standard primers, but not with mag. primers. The only concluesion I could come to was that some powders are harder to light than others. Most loads showed some but not a lot of velocity variation. I have several different brands of primers for larger and small rifle and have found that in some cases the primer will make a fair size different in group size, but most of the time it has little to no effect.

[williamlayton]

I really amd not going to do any experimenting---those days are gone---Really i just got to thinking about primers one day and I realized I did not know anything at all about them-therefore the question.
It has been fun and interesting- this little quest.
Blessings