Magnum Primers?


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Pictures
May 12, 2012, 11:25 PM
I bought some Mag CCI primers on accident. Do I need to decrease my powder charge in order to use these?

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T Bran
May 12, 2012, 11:28 PM
Unfortunately yes drop down and work back up.
Anytime you change a component drop back, the only exception is if you are already at or very near the starting charge weight.
T

Pictures
May 12, 2012, 11:38 PM
I'm at the limit.

Ok, will do. Thanks!

MovedWest
May 13, 2012, 12:47 AM
In my loading world I usually drop 5% off the powder charge to accommodate the extra fire of a magnum primer. But that's what I've worked out with my load data.

Since you're at the max, I'd err on the side of caution and work it back up. Keep good notes in case it happens again or there happens to be another run on components where regular primers are in short supply. Versatility is good. ;)

-MW

MachIVshooter
May 13, 2012, 01:09 AM
Generally speaking, magnum primers will increase chamber pressure by igniting the charge faster. As stated, you should drop it back a bit. Don't really need to work up from minimum, but I'd go right in the middle between min and max.

jcwit
May 13, 2012, 02:39 AM
Just asking, why are you loading at the max limit?

ArchAngelCD
May 13, 2012, 10:39 AM
Just asking, why are you loading at the max limit?
That was going to be my question too.

What caliber, bullet, powder and charge weight are you loading?

TonyT
May 13, 2012, 11:24 AM
I made a similar mistake when I was loading some very light 40 S&W loads (180 gr. bullets at ca 725-750 fps) and did not recognize that the box of primers I purchased were magnum instead of normal. When I chronohraphed those loads they were ca 10-20 fps faster than those with normal primers. I would not use them if the cartridges I loaded were at the upper end or max of the powder manufacturers data.

joed
May 13, 2012, 11:42 AM
Just asking, why are you loading at the max limit?


I have to ask why not? The world does not end at the max shown in a loading manual. It's a reference point and it's not set in stone. I've had many instances using Varget where I needed to increase the charge by 1.5 gr to get the velocity advertised. So far this is the only powder that has done that to me.

kingmt
May 13, 2012, 12:17 PM
I agree you can go beyond max in most books with most guns. I tend to be +/- 1gr of min for most of my rifle loads & just barley over min with most pistols. Except for one of my SD loads & that is because I need to push them pretty hard to get them to open. I could switch to a slower. Powder but they shoot so good & recoil is smooth. I'm about 1.2gr over with that load.

I don't see a difference with mags but it is possible that you could get better ignition so doesn't hurt to be safe.

Jasper1573
May 13, 2012, 02:03 PM
I have loaded up to the max in .308 Win using Lyman's data for SMK 175s and the Hornady AMax 178s. I found a slight increase in velocity, a slight decrease in accuracy, and a significant increase in perceived recoil.

Didn't see the point in loading at or above the max just to receive an extra beating at the expense of accuracy...then again, I am not shooting an elk. If I were, I might load up to the max load, but white tails are easy to bring down.

Pictures
May 13, 2012, 03:33 PM
That was going to be my question too.

What caliber, bullet, powder and charge weight are you loading?
Why am I loading at max?

Should I not be doing this? I mean, they work, the rounds have a sufficient feel to them so that's what I've been going with. I'll admit I don't know anything about ballistics or velocities or any of the science behind it, I simply know that they work, but I'd be interested in hearing arguments against doing so.

My load info, as requested:

Brass: once fired mixed head stamp
Bullets: Berry's .45 acp 230gr round nose FMJ
Powder: 5.6 gr (+/- .2gr thanks to my lee auto powder measure) of Clay's Universal
CCI Primers

Lost Sheep
May 13, 2012, 03:52 PM
Juvenile and not THR.

Loading to maximum is a choice. Most people find their gun's "sweet spot" for accuracy somewhere between minimum and maximum. Kingmt (post #10) has found his bullets' terminal performance "sweet spot" above max, but presumably has searched for pressure signs and found none, so for his gun, that is OK.

I imagine that if a ballistics lab worked up loads using Kingmt's gun, the max load would be at his load or maybe even higher. Each gun is unique and its own max load might be above or even below the "book" max. That is why we start low and work up.

Anyhow, the boldfaced part is the argument against loading at max. There is another argument (for those who have more than one gun in the same chambering) to be made for not using any load at or even near max that has not had that load worked up in that individual gun.

Lost Sheep

Pictures
May 13, 2012, 04:09 PM
If I remember correctly, I started loading at the minimum and when I shot it, it felt really weak compared to the factory ammo I had shot, so I went ahead and maxed it and it seemed about the same power as the factory ammo.

I also used this site as a reference. It seemed like a lot of people, using the same powder and similar bullets, were using much higher gains that I were and they said it worked fine, so I figured I was safe at 5.6. I never even tried to find this "sweet spot" you speak of. Maybe I should go back and do that?

http://forums.1911forum.com/showthread.php?t=255286

joed
May 13, 2012, 04:23 PM
Why am I loading at max?

Should I not be doing this? I mean, they work, the rounds have a sufficient feel to them so that's what I've been going with. I'll admit I don't know anything about ballistics or velocities or any of the science behind it, I simply know that they work, but I'd be interested in hearing arguments against doing so.

Nothing wrong with loading to max, and remember that it is not written in stone that the max is really the max safe load. You may find an instance where you can't shoot a max load from a manual without pressure signs, and you may have an instance like I mentioned where you have to go beyond max. The trick is you work up to that load. It's nice to have a chronograph for this reason and read the cases.

Ky Larry
May 13, 2012, 04:33 PM
The reason I load for accuracy and not velocity is that a hit with a .22 short is better than a miss with a 20mm cannon. Who cares how fast a round is if it's not accurate?

jcwit
May 13, 2012, 04:34 PM
I load for accuracy, and usually thats far below max. I get more loads per pound of powder, my brass lasts longer, usually as much as 100 reloads per case in .223. And guess what? The paper target dies just as quickly and without suffering. But as always YMMV.

Pictures
May 13, 2012, 05:09 PM
I want to load for accuracy too, so maybe I should start from scratch?

Btw, keep in mind that I'm loading to the max according to one manual. Apparently others put the max for my components at 6.0 grains, so on that scale, I'm not at max.

I think what i'll do is make 20 rounds per varying load, try them out, see what groups the best then go with that.

joed
May 13, 2012, 07:17 PM
I load for accuracy, and usually thats far below max. I get more loads per pound of powder, my brass lasts longer, usually as much as 100 reloads per case in .223. And guess what? The paper target dies just as quickly and without suffering. But as always YMMV. You're a minority, every rifle cartridge I own gives its best accuracy very close to the max loading. It suspect it has a lot to do with air space in the case though I can't vouch for that.

That's rifles, pistols are different. There are a lot of things that effect the accuracy of a pistol.

Lost Sheep
May 13, 2012, 08:04 PM
If I remember correctly, I started loading at the minimum and when I shot it, it felt really weak compared to the factory ammo I had shot, so I went ahead and maxed it and it seemed about the same power as the factory ammo.

I also used this site as a reference. It seemed like a lot of people, using the same powder and similar bullets, were using much higher gains that I were and they said it worked fine, so I figured I was safe at 5.6. I never even tried to find this "sweet spot" you speak of. Maybe I should go back and do that?

http://forums.1911forum.com/showthread.php?t=255286
The "sweet spot" thing is more applicable to rifles than to handguns. Supreme accuracy is more apparent ar rifle distances than at handgun distances. Which are you loading for? (When I posted my earlier answer you had not provided the clue of the 1911forum link.)

Finding the sweet spot for a rifle involves some experimentation and sorting out barrel harmonics (also known as "barrel whip") other esoterica that is, frankly, beyond me. But truly worth it when you find a load that turns your 2" 100 yard groups into half-inch groups.

I forgot one point about why people often shy away from the maximum load. Powders burn at a rate that depends on the pressure. Outside that range, they (may) burn erratically. In most firearms and for most powders, the optimal, most uniformly burning pressure will be found between the high and low extremes. Consult the science of "Internal Ballistics" for more detail.

For that reason, many (not all, by any means, but at least some), if they find the bullet velocity that is most accurate in their barrel and discover that it is at the high end of the powder charge range, will switch to a powder that delivers that velocity closer to the middle of the charge range and search for the sweet spot with that charge weight.

For handguns, the reasoning is probably more for safety, and this applies to rifles as well. A slight overcharge (it happens) if you are already at pressures approaching the limits of safety is more dangerous than a slight overcharge if you are in the middle pressures.

In closing, the search for the perfect load is like tuning anything. Arranging the perfectly composed photograph or flower arrangement. Tuning dual SU carburetors so finely that you can balance a nickle on a 4-cylinder engine idling at 300 rpm. I was not able to do that last one, by the way, but the search for it was reward enough. If you can understand the quest for the impossible, you owe it to yourself to try doing it, if not with your firearms, with something.

Lost Sheep

kingmt
May 13, 2012, 08:06 PM
Like I said in a post above, I get my best accuracy +/- 1gn of min.

As far as the load worked. Yes. My pistol is a tank & the slide is very havey. There is no +P data for this powder but I doubt it is over that. It is also my SD round so it isn't likly any more will be shot through it.

I normally load where it just does function the slide. No need to beat up my guns for no reason.

You can't check pressure by felt recoil. I also wouldn't strive for factory loads. I shot one the other week 9mm 187 fps.

Lost Sheep
May 13, 2012, 08:09 PM
You're a minority, every rifle cartridge I own gives its best accuracy very close to the max loading. It suspect it has a lot to do with air space in the case though I can't vouch for that.

That's rifles, pistols are different. There are a lot of things that effect the accuracy of a pistol.
Joed, I know that you know that filling the case (or even having a compressed load) is NOT the same as the maximum load, but some readers could misinterpret your post.

And, yes, having empty (air) space in a case can make a HUGE difference, in velocity at least. I have observed this first hand myself simply because of powder position within the case. Some shooters deliberately pick powders that not only are mid-pressure range, but case-filling as well just for that reason. Others simply fill the empty space in the case with an inert filler.

Muzzle loader shooters are, of course, not concerned with air space because with their loads there never is any.

Lost Sheep

Pictures
May 13, 2012, 08:24 PM
Lost sheep, it's .45acp for pistol.

coalman
May 14, 2012, 12:42 AM
You should drop down and work back up. I never do and it's not mattered.

ArchAngelCD
May 14, 2012, 01:15 AM
Actually, when I agreed with the question, "Just asking, why are you loading at the max limit?" I read it too fast and thought the question was, "Just asking, what are you loading at the max limit?" That's why my next question was, "What caliber, bullet, powder and charge weight are you loading?"

Pictures
September 25, 2012, 11:02 PM
Decided that I would try this load. I was hoping to post it here and see if anyone thinks I have too high of a load. Just trying to be safe here.

5.4 grains of Clays Universal
CCI Magnum primers
230gr rn bullets

Pictures
September 26, 2012, 09:36 AM
Fine, I'll just blow my face off then!

wardor
September 26, 2012, 10:48 AM
For plated bullets, they recommend using Lead loading data. Hodgdon.com lists

230 GR. LRN
Hodgdon Universal
.452" 1.200"
4.5 703 11,400 CUP - min
5.4 857 16,800 CUP - max

45 ACPs tend to do the best with 230gr right around 800fps for accuracy. With Magnum primers I'd start at 4.7 or 4.8 and work towards 5.0-5.1

wardor
September 26, 2012, 10:49 AM
Also, what is your COAL? COAL has a great deal to do with pressure and velocity.

Pictures
September 26, 2012, 11:13 AM
I guess my reloading doesn't get all that technical. I just seat them under the max legnth listed in my manual.

How would I know if I'm getting 800fps? I'm guessing it involves math of some sort.

wardor
September 26, 2012, 11:15 AM
Chronographs are the only accurate way, but the loading manuals are pretty accurate for most people, so its usually pretty good if you match their data.

Pictures
September 26, 2012, 11:38 AM
Ok, I'll bullet-pull the ones I made with 5.4 and dial it back a bit. Thanks!

wardor
September 26, 2012, 11:40 AM
You can shoot em, nothing is dangerous, and there are variations from pistol to pistol. The 800fps 230gr is more of just a standard over time. 5.4 is max with normal primers, but the pressure is not scary at all. If you have enough extras around, just shoot em and dial it back.

Pictures
September 26, 2012, 11:44 AM
I only made four at 5.4. I just don't want to damage the gun.

wardor
September 26, 2012, 11:48 AM
It won't damage the gun at that load, unless your COAL is like 1.170, then possible.

Pictures
September 26, 2012, 12:03 PM
I don't remember offhand but I believe it's 1.65 or somewhere around there. That's assuming I have the def of COAL correct. It's the overall length of the cartridge, correct?

wardor
September 26, 2012, 12:03 PM
Yes.... from base to tip

wardor
September 26, 2012, 12:06 PM
I'm guessing you left our a number too... 1.65 is very long, guess you meant either 1.165 or 1.265

Pictures
September 26, 2012, 12:16 PM
Ha, probably. I'll post back later tonight when I get home.

Andrew Leigh
September 26, 2012, 03:36 PM
It is like golf ...... less is more. Less force better result. Unfortunately we live in an age which requires that we max everything. This obsession is both destructive and counterproductive. I could not care how fast you bullet is but how well you shoot.

My 30-06 loads are below the suggested speed but work great in my rifle ....... they are almost always sub MOA at 100yds.

Pictures
September 26, 2012, 06:37 PM
Ok, so we're looking at in the neighborhood of 1.268 COAL. I've decided to scale it back to 4.7. Sound ok?

Pictures
September 26, 2012, 08:44 PM
I made six rounds using 4.7 and six rounds using 5.1. I'll try them both and see which one is more accurate.

As far as safety goes, I should be well within the safe zone, correct?

ArchAngelCD
September 27, 2012, 01:12 AM
Ok, so we're looking at in the neighborhood of 1.268 COAL. I've decided to scale it back to 4.7. Sound ok?
Using that OAL you don't even need to pull the bullets you made with 5.4gr since Hodgdon lists an OAL of 1.200". I also feel you don't need to drop back to 4.7gr, starting at 5.0gr will be fine. Even though magnum primers will burn slightly longer and slightly hotter than standard primers they don't create a nuclear explosion.

Lost Sheep
September 27, 2012, 03:39 AM
Overall length is measured from base of the case to tip of the bullet. But that is not REALLY what you want to measure. Unfortunately, that is the only thing we CAN measure.

The real measurement you want is the volume inside the case.

The length from web to bullet base is a proxy measurement for that volume. But we can't measure that directly.

The overall length of the cartridge is a proxy for THAT measurement.

The overall length of the cartridge can vary considerably based on the shape of the nose. If you have a perfectly round nose profile vs a more elongated curve vs a spitzer point you can easily see that overall length is an imperfect proxy.

Fortunately, 45 ACP bullets don't vary that much in shape. But hollowpoints will make a difference.

So, as promised, I will get technical now.

If you have a bullet of a given weight and load data (including OAL) for a differently shaped bullet of the same weight, it might be worthwhile to find the different in actual bullet length and adjust the recipe's OAL to account for that difference.

Reloading isn't rocket science, but it does involve smoke and flame and things that go terribly fast. Pay attention to detail and you will be fine.

Your caution about shooting the few cartridges you feel are heavily loaded is commendable.

On the good side, the 45 ACP is a fairly low-pressure cartridge developed over 100 years ago and modern guns are built of a bit stronger metal than back then. Your loads are probably good to go as long as the internal volume is not too small. But only cartridges? Pull them. It's good practice and a good practice. You don't have to punch out the old primers. Just re-bell the case mouths, charge the cases and seat/crimp the bullets.

Lost Sheep

Clark
September 27, 2012, 05:54 AM
Magnum pistol primers make extra pressure like 0.7 gr extra powder.
They do not make extra velocity like .7 gr extra powder.

With 9mm, 38sp, and .223, there are huge amounts of safety margin, so it does not matter much.

But stock 1911 barrels in 45acp sometimes are getting close to the case bulge.

The 45acp case web is 0.18" thick.
Some 1911 barrels have .235" of feed ramp intrusion.
That makes for .055" of thin unsupported case wall.
The case wall is ~ .015" thick, and so we have a bridge over a hole that is 4 times wider than it is thick. That wants to blow a bubble.

If some "gunsmith" modified the barrel with a Dremell or Fordham rotary tool turning Cratex rubber bits with embedded abrasive to "polish the feed ramp", then thing may be worse.

Friendly, Don't Fire!
September 27, 2012, 06:15 AM
All this could be easily settled by using a chronograph and comparing like bullets to like bullets of the same weight.

If your bullets are not traveling anywhere near as fast as some factory loads, then you can most likely use the primers with your loads without issue. You may even find that your bullets WITH magnum primers do not meet the velocities of some factory ammo.

Some factory ammo is especially HOT.

Pictures
September 27, 2012, 06:44 PM
Thanks for your help everyone. Hopefully I can find that sweet spot.

Pictures
September 29, 2012, 02:34 PM
Just a quick update. 4.7 wasn't very accurate, but 5.0 was fantastic. I think I'll go with that.

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