Is Primer Brand a must?

[sawdustdad]

I've routinely substituted primer brands (not type) without issue. Again, starting with reduced loads. Only loading metallic cartridges, though. I'll try to match the load manual if I can, but references to various manuals will give different brands. So you've got to make a call and go with it.

[Arbitrage]

Unclenick,

Very helpful guidance - thanks to you, I will be safe and start 15% less powder than the recipe unless I use the exact primer they say. I did not know about the .308 Win brass being so inconsistent. Do you have a favorite powder for 308? I will be using 165 gr Hornady projectiles.

[trapper9260]

I have a 308 semi auto and use IMR 4064 and I shoot cast and jacket in it.I use what ever primers I am able to get.But mainly shoot Win and some Rem.As for the data of what the OP talking about one type of primer is also they say to use that one kind is also because of the Lawyers. It is up to the user for what the out come and also each gun will shoot differnet at one point.If you have a number of powders on hand and for the data you have match some of your powders i say make some test rounds of about 5 and use the starter load of each of the powders that is on the data and then see what one will work the best in that gun and then after work on that one powder to get that gun to shoot the way you like it to.As for shotgun I do not worry about what type of primers I use mainly.when you patten you shot on that just make sure you do not have a hole in your patten ,if there is then you are over power and need to reduce your load.

[Arbitrage]

Another two (2) questions please:

1. When I read something like, 'It's running right around 26K psi' - how does a reloader know that? Is there a tool that measures pressure? Or are they calculating by using velocity and weight and backing into pressure somehow?

2. Where do you typically pickup your reloading supplies? MidwayUSA or local? Curious if you have a good place price-wise of if sticking to Midway is acceptable.

Thanks!

[mehavey]

A couple of interesting references:

http://castingstuff.com/primer_testing_reference.htm
http://practicalrifler.fr.yuku.com/r...ink#reply-7150

http://www.6mmbr.com/PrimerPix.html

[Arbitrage]

mahavey,

Awesome primer references - thanks!

[stubbicatt]

I remember watching some TV show a while ago where they were showing how CCI 22 long rifle cartridges are primed. There is an operator with a tray full of moist priming compound, and they sort of smear it over the cartridge cases, and it gets pressed to the bottom of the rimfire cases, which are then spun to distribute the paste to the rim.

Anybody know how priming compound is put into boxer primers? Is it similarly done?

From what I saw, it was not a scientific method used with the 22's, but the operator sort of eyeballed the thickness of the paste and then smeared it over the cartridges, IIRC. If this is the method used to make centerfire primers, I would tend to believe that there would be as much variance between lots of the same manufacturer's primers as between primer manufacturers. Anybody know if priming compound is dispensed into primer cups by a more reliable method, whether weight or volume?

Perhaps an answer might give us insight as to the variances present in primers in general enough to extrapolate whether substituting one brand of standard rifle primer for another is an issue.

Though I do know that the compounds used in primers vary from manufacturer, with Federal using a different compound, with less glass and what not than say CCI. I've seen photos of tests where the set off different primers in effort to compare the sparking and flaming from each.

[Gadawg88]

Pressure testing requires very, very expensive equipment and is typically done in labs by powder manufacturers or other shooting industry companies. That is why we follow load data that has been compiled by reputable companies with that equipment and expertise.

To find powder right now, particularly pistol powder, requires persistence, patience and time. The good news is it can be had given some quantity of those three things (and maybe a little luck thrown in). Make a list of powders you can use and prioritize it 1st choice 2nd choice etc. Then, get a list of online retailers that sell powder and bookmark them in your browser sorted so they are all together. Here are a few good ones:

Powder Valley
Graff and Sons
Wiedner's
Midsouth Shooters supply
Recobs Target shop
Third Generation shooting supply
Gamaliel supply
Ballistic products
Precision reloading
Cabelas
Bass pro shops

Check them every day, multiple times a day and be prepared to place an order the moment you see one of your choices available. You can not wait and think about it. The more choices you have on your list the better your odds, but be mentally prepared to wait a while. You never know when your gonna get lucky. Also check Gunbot.net. Good luck.

[Arbitrage]

Gadawg88,

Thanks for all the links to places that sell components. I found a good price on .357 Mag. projectiles... 9¢ each but they are 'plated' and I am told not to load Magnum loads. I guess I can use them but need to find a recipe that is not a 'magnum' recipe for 125 gr.

Here was their official description/warning at Graf & Sons: Berry's Preferred Plated bullets begin as a swaged lead core. The swaged lead cores are tumbled in an electrically charged bath containing high-grade copper ingots. The copper clings to the lead and the longer the bullets remain in the bath, the thicker the plating. The bullets are plated to the correct size and then taken out of the bath. Plated bullets are not as expensive as jacketed bullets. They are cleaner than lead but you'll want to stay away from magnum velocities when loading plated bullets.

[Gadawg88]

I load a lot of plated bullets in 9mm and 45acp, just not .357 mag yet. It is on my list of things to experiment with though. I would recommend that you find a load that keeps them at the lower end of .357 velocity, 1200fps or less. To date I have only loaded fmj (Hornady XTP) and some hard cast lead bullets in full tilt .357. A good roll crimp is needed which could be an issue with plated bullets especially those with thinner plating. I am not sure how the Berry's rank in that regard, but others can chime in I am sure. Check out X-Treme bullets if you haven't already. All their HP bullets (non-expanding) have a heavier plating and can be pushed harder according to their loading advice:

"All Hollow Points are Heavy Plate Concave Base but are not designed to be used as a defense round.

Our Copper Plated Bullets can be run at mid-range jacketed velocities or higher end lead velocities. We recommend keeping velocities to less than 1500 FPS (Feet Per Second) and using only a light taper crimp

Any velocities over 1200 FPS we recommend either our Heavy Plate Concave Base or Hollow Point products for superior accuracy. We recommend keeping velocities to less than 1500 FPS (Feet Per Second) and using only a light taper crimp

All of our Hard Cast Lead Bullets are approximately 18 on Brinell, our Cowboy lead bullets are approximately 15 on Brinell."

You might consider starting a new thread on the topic if you want to dig deeper.

[Arbitrage]

OK, Got it. Now I will look to figure out how to do a light taper crimp rather than a regular taper crimp.

[9mmSkeeter]

Once, I used a Federal primer instead of a CCI. I died.

[RC20]

rkitine:

Thank you for the link, one of the best background discussions on primers and the variation and reasoning for not publishing tables.

As much as I appreciate your input, I do think the advice not to go to a different primer is both unrealistic and not supported by experience. Its understandable from the mfg/data published standpoint listing what they used so you can duplicate the results, but you are also not going to jump (should not) to the maximum loads used, i.e. work up.

I would put this as a series of rules or strong advisories:

1. Don't ever start at the max loads, 5% down, mid level, 10% down, but never maximum

2. Maintain the same primer type (magnum, regular) for the load, they know a lot about how that powder worked in that cartridge.

3. Spherical powders are a special case and probably should not vary the primer type (always stick with magnum if that's what it was worked up with.

4. Cold weather is a special case (though I would not call 20 degree severely cold!) You may need to move to a magnum prime.

Do your research and see what the various mfgs do with the same powder and case and all other data and come to an informed decision.

5. Low case loads are a special case and should be carefull

[Bart B.]

Anybody know how priming compound is put into boxer primers? Is it similarly done?

A Federal rep at the Nationals one year told a bunch of us how they do it. Probably not much different than any other company.

First, a chemical mixture of the primer pellet stuff is mixed on a table with straight edge paddles much like chocolate fudge on a granite slab is mixed. He said that's the "black magic" part of ammo making as some people do it very uniformly than others as evidenced by testing different lots of primers and person A mixed that "slurry" better than person B.

Second, a flat metal plate with holes in it sized for the primer pellet has that slurry smeared into it; as evenly for each one the mixer person can do. At the bottom of those holes is another plate with round pins part way up into the holes. Each hole's depth is the same. The slurried plate is set aside to let the primer pellets dry. They shrink a tiny bit after they're dryed, but they're still quite uniform in size.

Third, the pellets are pushed out then put in an assembly line where they go in one input and primer cups made by the coin, cup and draw process have been put in another input. The pellets are pushed into the primer cups to some depth so they rest on the bottom.

Fourth, near the end of that assembly line, a foil seal is then placed over the primer pellet.

Fifth and finally. at the end of the line, the anvil, made from a cut and stamp machine, gets pushed into the sealed cup just the right depth.

Samples of each lot are tested by dropping a weighted pin on them put in a special testing chamber. There's a range of impact force they have to fire normally at. They're also tested for muzzle velocities in a test barreled action and those with the velocity spread less than some number are set aside to be labeled as match grade primers. I wouldn't be surprised if they used a primed .17 Rem case to shoot BB's through a smooth bore barrel across a chronograph. That's been done before testing primers using velocity spread as an indicator of primer uniformity.

Then they're boxed and sold to retailers or put in their own ammo.

I'd much rather watch and learn how the people think up, design, then operate the machines and tooling used to make the machines and tools that make ammo components. They're the ones who should get the most credit for the ammo or its component quality. Once that's done, training someone to operate them properly is easy, for the most part. Except for the primer pellet slurry mixing where all those chemicals have to be mixed by hand very uniformly fo have consistant performance across a given lot of primers.

[TMD]

As much as I appreciate your input, I do think the advice not to go to a different primer is both unrealistic and not supported by experience. Its understandable from the mfg/data published standpoint listing what they used so you can duplicate the results, but you are also not going to jump (should not) to the maximum loads used, i.e. work up.

I would put this as a series of rules or strong advisories:

1. Don't ever start at the max loads, 5% down, mid level, 10% down, but never maximum

2. Maintain the same primer type (magnum, regular) for the load, they know a lot about how that powder worked in that cartridge.

3. Spherical powders are a special case and probably should not vary the primer type (always stick with magnum if that's what it was worked up with.

4. Cold weather is a special case (though I would not call 20 degree severely cold!) You may need to move to a magnum prime.

Do your research and see what the various mfgs do with the same powder and case and all other data and come to an informed decision.

5. Low case loads are a special case and should be carefull

While most powder loads have about a 10% variance between minimum and maximum some such as H110/W296 only have a 3% spread.

[hartcreek]

It isnt just .308 cases that vary so much but each brand is made a different thickness so when you are working with mixed headstamps you need to weigh and seperate them and start working your load up with the heaviest cases.

[Arbitrage]

Thanks everyone!