Powder Quantity Exceeds Case Capacity

[Fox1]

Because of all of the shortages of reloading supplies, I'm developing new loads with powders I don't usually use because I can't find my "usuals" all of the time.

I noticed that on some powders, the charge weight listed in the book actually exceeds the case capacity.

What is going on with that?
How can the manufacturers list a charge that won't even fit in the case?

Info:
.223 REM
50 gr. bullet
WIN 748 and IMR 4320
Hornady 7th Edition
Also using my "homemade" book which is data sheets that I printed off of the Hodgdon/IMR/Winchester web site.

[brickeyee]

Use a longer drop tube.

[SKULLANDCROSSBONES65]

G'day. I keep hearing that the 5.56 military case has less case capacity.
How many grains can you get into your case?

[HiBC]

Both previous suggestions are correct

A drop tube will settle more powder into the case,but Skull's suggestion is important.Mil-spec brass has thicker case walls,lower case capacity,and,if the powder would fit,the load would produce higher pressures,possibly unsafe.

An aside,the Win ball powders,such as 748,can have problems when compressed,especially in high temperatures.

Gathering data off the web is fine,but I highly suggest you own and read at least one,and preferably two,loading manuals.There is a great deal more in them than just data.
The information about the process of reloading is important and they discuss substituting components.

I understand"improvise,adapt,overcome" and the shortages,there is a safe path to follow,and it is in the books.

[Teuthis]

Use the manuals. Do not try to invent your own loads. Exceeding case capacity is remarkably dangerous, and usually disastrous. Ballistics is too complex and volatile to play with. I would not use any load I do not find in a manual from some universally respected source, such as the powder makers or bullet makers. I recommend the Lee loading manual, second edition, among others.

If you explode a gun, you not only kill or blind yourself, but those on either side of you at the range.

[PCJim]

Fox, maybe if you would provide us with the published recipe you are referring to for the .223/50gr bullet, it would help. You listed the two powders (W748 and IMR 4320), but at what loading weight?

I have never run across a published recipe that would overflow a case, but then again I haven't tried that many powders for the calibers I load for.

[brickeyee]

Exceeding case capacity is remarkably dangerous, and usually disastrous.

There are many loads from manuals that are compressed.

[Unclenick]

Yes. You're going to get a lot of contradictory remarks about it this way. Give use the actual bullet, case, primer and powder charges you are looking at. Note that when you take a load from a manual you have to use the same brands of case and primer and use the same COL they did to get the same performance from their recommended charges. Components are not interchangeable, and just because a load works a certain way with one brand of 50 grain bullet, doesn't mean it will with another brand. Any time you change a component you have to knock the powder charge down 10% and work back up.

I can tell you right off that IMR4320 is too slow burning and too bulky for a 50 grain bullet in .223. A case just filled 100% (no compression) only generates about 38,000 psi and 2900 fps from a 20" tube with a bullet that light. Not really adequate for AR operation, and the low pressure won't burn the powder as consistently as normal peak pressures would.

748 is more dense than 4320, and a case 100% full short of compression runs right around 52,000 psi and produces almost 3,300 fps from the same 20" barrel. It is much more reasonable from the standpoint of theoretical performance. But because it is a fine ball powder, I would use a magnum primer with it and because of that, would start with the case at about 90% filled space under the bullet.

Frankly, heavier bullets than 50 grains would make both powders much happier. 69 grain match bullets like 748 very well. IMR4320 does its best .223 work with the 77 grain Sierra MatchKings, but you still need a compressed load to get to full chamber pressure. 4320 is just not a good .223 powder. It really performs most effectively in something like .30-06 with 180 grain bullets.

[snuffy]

Teuthis
Senior Member

Join Date: 2008-04-09
Location: Southern Arizona
Posts: 196

Use the manuals. Do not try to invent your own loads. Exceeding case capacity is remarkably dangerous, and usually disastrous. Ballistics is too complex and volatile to play with. I would not use any load I do not find in a manual from some universally respected source, such as the powder makers or bullet makers. I recommend the Lee loading manual, second edition, among others.

If you explode a gun, you not only kill or blind yourself, but those on either side of you at the range.

A list of generalities, mostly wrong. He is using a manual, he lists the Hornady 7th edition. And the loading info posted on the Hodgdon website, among others, is just as good as any manual.

Compressed powder charges, that are usually listed as compressed, have been used for years. Usually, they're trying to use a slower than optimum powders, trying to get to a usable power level.

Fox, use a powder funnel to charge the cases. Not a powder measure to simply dump the powder straight into the case. Pour from a scale pan onto the side of the funnel. You'll notice that the powder swirls around the exit hole. This will arrange/pack the power more tightly than if it were dumped.

[Archie]

Do not despair, this is an old problem.

All brands of cases vary in capacity; and from lot to lot. All guns are different and react to loads in different ways, slightly.

Some loads are in fact compressed; that is, one must jam the bullet down on top of the load to make it all fit.

Some powders are indeed too slow burning to be dangerous. For instance, a case full of H4831 in a .32 ACP cannot possibly develop enough pressure to blow up the gun. (It won't develop much velocity, either.)

And, as pointed out, not all 50 grain bullets are identical. Some are longer and take up more case space, some are harder and therefore take more pressure to engrave them into the lands.

So; what to do? Is the starting load small enough to fit in the case? If so, start there and work up. I'd quit when I got to a full case and the charge lightly compressed. If accuracy or velocity doesn't suit or satisfy, try another powder.

[Fox1]

As I stated, I AM using a manual, Hornady 7th Edition, and data pulled directly from the Hodgdon/IMR/Winchester powder charge tables.

I'm working these loads up for a Remington 700 VTR in .223 Rem.

Here are the specifics, from the manual and the web tables.

WIN 748
Book 24.5, 25.1, 25.9, 26.7, 27.5, 28.3
Web 26.0

IMR 4320
Book 25.0, 25.7, 26.5, 27.2, 27.9
Web 24.8, 27.5


Here are the components I used for each powder.

FC 06 Case, Federal Sm. Rifle Primers, Remington 50 gr. PLHP

WIN 748 - I loaded 24.5, 25.1 and 25.9.
I stopped at 25.9 gr. because that charge filled the case to the top of the shoulder.

IMR 4320 - I loaded 24.8 and 25.0.
I stopped at 25.0 gr. because that charge filled the case to the top of the shoulder.

I'm loading the powder by dumping from the powder pan directly into the case.
I do not want to get powder into the neck because I do not want to compress the powder.


As an experiment, I tried loading the highest charged powder (ONLY) weights, (WIN 748, 28.3 and IMR 4320, 27.9) into 2 separate cases to see if they would even hold that weight. Both of them ran powder over the neck.



I appreciate the concern that some have voiced about me blowing my face/fingers/gun apart but I want to assure you, I am very cautious when loading; triple checking my scale, the book, the Internet tables and the packaging that all components come from.

If it weren't for the fact that H 335 and 55 gr. .224 diam./ .22 cal. bullets are such hard commodities to find these days, I'd probably still be loading those.


Also, thank you to those who pointed out that WIN 748 and IMR 4320 are slower burning powders. I didn't realized that so, before replying, I did some more digging on the Internet and found a chart that gives an "approximate" listing of powders from fastest to slowest.

Since I have these cartridges loaded up, I'll shoot them at the range and take notes to see which loads work the best.

Would these two powders be better used for .308 WIN or .270 WIN loads?

Also, back to the original question, Why would these sources list charges that won't fit in the case?

[Archie]

Also, back to the original question, Why would these sources list charges that won't fit in the case?

I'm sure it did fit for whoever put it together for the loading manual.

As I pointed out, cases vary in internal capacity from manufacturer to manufacturer, and from this lot of brass to that lot of brass. Also, the chambering reamers to make sizing dies vary by a very small amount. So some dies will create a (very slightly) smaller internal space than another.

In one sense, it's the same reason all of us don't look alike.

[CrustyFN]

I think your book is off. I don't have the Speer #13 in front of me but I am thinking max for a 55 grain bullet is around 26 to 26.5 grains. W748 is one of my main powders for 223 and I have never come close to filling the case.

Rusty

[Unclenick]

Archie is correct. Case capacity can vary several grains. SAAMI only specs the exterior case dimensions and the maximum and minimum neck thicknesses. Whatever else happens inside is up to the brass maker.

I would double-check the water capacity of the Federal cases. The Hornady manual loads will have been created using Hornady/Frontier cases. Cases are not interchangeable except with starting loads, and sometimes not even then. Hodgdon site loads will most likely have been developed with Winchester cases which are generally the most capacious you can buy. When you get a listing of loads at Hodgdon, click on the "Print" button and a window will come up previewing the printed form and showing the make of the case used. I believe I've seen over 3 grains of water capacity spread in .223, but I am pulling that number from memory and it may include some 5.56 NATO cases from other countries. Also, are you using a small base sizing die? That would subtract some extra volume.

Just for grins, take a look inside the cases you are charging and make sure nothing foreign is in there. On one occasion I had a case overflow because some kind of insect had nested in it. On another, I observed the powder level in a Lake City .30-06 was just too tall. I emptied it onto a scale pan and it was a correct charge. I got out the flashlight and saw a dark mass near the primer pocket. I turned it over and tapped the case mouth on my bench. Nothing. I poked it with a long wood stick handle on a medical swab and could feel a lump but it wouldn't budge. Finally I got in there with a dental pick and the object popped loose and I could rattle it in the case, but I had to use needle nose pliers to extract it through the mouth. It was a flattened slug of lead bullet core. I had fired this round new, myself, so this was a factory bonus. So, you never know till you look.

Using a drop tube will compact (not compress) powder in a case, sometimes considerably. You can buy funnel sets with drop tube extensions for the purpose. They are also available for some measures. This is not the same as compressing powder because when you transport ammo, powder gradually shakes down into more compact form anyway. I would not hesitate to use drop tubes.

[CrustyFN]

OK so a bad memory is the second sign of old age. I was off a little on my other post. I checked my Speer manual and for a 55 grain bullet it calls for 26 grains of W748 as start and 28 grains as max. The 28 grains is a compressed load.
Rusty

[Gewehr98]

1. FC-06 sounds like a milspec headstamp, meaning thicker mil-surp brass, and subsequent smaller case capacity.

2. Like Crusty mentioned above, my Speer #13 Manual shows 28.0gr of WW748 as a compressed load for .223 Remington. I'd wager that Speer probably used commercial brass. You're using military brass, with even less internal case capacity.

3. Why are you so creeped out about compressed loads? It's not a big deal, and has been common since black powder cartridge days. Use a 4" powder funnel, and drop back the standard grain or so when using military brass to keep pressures down.

[Fox1]

1. FC-06 sounds like a milspec headstamp, meaning thicker mil-surp brass, and subsequent smaller case capacity.

It is milspec; I had to ream out the primer pockets before I reloaded these.

3. Why are you so creeped out about compressed loads? It's not a big deal, and has been common since black powder cartridge days. Use a 4" powder funnel, and drop back the standard grain or so when using military brass to keep pressures down.

Because I'm new to reloading and I don't want to rush out and try all of these things until I'm very confident about the basics. Until last week, I never even heard of compressed reloads.

[Scorch]

If you want to load the full charge listed, lightly tap the side of the case with a pencil or something similar as you put the powder into the case to settle the powder. With 4320, you may be able to get the remaining powder into the case. Unfortunately, tapping cases loaded with ball powder to settle the powder has little effect since the ball powder settles pretty uniformly to begin with.

[wild willy]

Did you try what Snuffy said swirling the powder in instead of dumping till you try you won't believe how much more powder you can get in a case

[Gewehr98]

Roger that.

Military brass is thicker, with a subsequently smaller internal volume.

It's a pretty common reloading caution to back off a grain or more when using commercial loading data with military brass. That makes good sense, because you'll run higher pressures per given load with that smaller volume case, and you won't get as much powder in there to begin with anyway.

I'll almost guarantee that published 28.0gr WW748 compressed load won't fit in military brass, and that a 27.0gr load will probably still be compressed if you don't use a drop tube to settle the charge on the way in.

Your caution is warranted, but you're just running into one of the quirks of using military brass, which is just fine once you get around the idiosyncrasies thereof. Tricks of the trade, and all that...

[HiBC]

I don't have anything against a lightly compressed load,

And,I haven't been using 748.For what it is worth,I have read that there were some problems with .458 Win performance on African safari's that were traced back to compressed loads of 748.Something about it caking or clumping up and not having the same burn characteristics.I think heat contributed.

I know,it is sketchy info,perhaps someone knows more about it.

I just made note to myself avoid compressing WW ball powders

[Unclenick]

Fox1,

Give me your case length and measure the water capacity of a fired case you still haven't de-primed. This is done by measuring the case weight, then filling that case level to the mouth (no meniscus) with water and weighing it again. The difference in the two weights is the case water capacity in grains.

I am getting curious about this. I wondered if there is any chance the cases were a special purpose military cases, but there is no way to know without the water weight capacity being known.

[Fox1]

UncleNick, I checked last night and I don't have any of the FC 06 cases that I can use to do the water test.

I have about 25 loaded and ready to shoot, 25 that have been primed and then 200 or so that have all been resized, polished and ready to load.

If I can shoot this weekend, these cartridges in this thread are the ones that I'll be testing so I can measure one after that.


I don't think they are anything special since they came in a bag of 1000 mixed headstamp .223 brass that I ordered when I started reloading.

[Unclenick]

You might check what the size cases weigh compared with some of the other brands you got? External head dimensions are never quite identical, but it will give some idea.