Starting to get low on 223 brass so broke out a batch of Federal cases I haven't loaded before. My normal trim length is 1.750" but I use any case 1.745 to 1.755. All these cases run 1.730 to 1.740" My loads have a OAL of 2.250. If I use this length I am going to have less bullet in the case. as much as .020" less. Should I save these for my longer 67gr bullets, or am I just over thinking this. These are my plinking loads?

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USN Retired/VN VET
M&P X5

I think the SAAMI spec is 1.740 - 1.760 for 223, so the most you are under is 0.010. Have you sized them yet? If not, size them then re-measure. Personally, I would load them up and shoot them even if they are still a little under, especially since they are just plinking loads. Depending on how hot you load them, they will probably stretch-to-fit after a few loadings.

I don't load hot normally just above starting loads is where I find my best groupings. I have not run these through the resizing die yet as I stuck a case in the die last night and as I have two dies with stuck cases I ordered a stuck case remover which will be here in the morning.

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USN Retired/VN VET
M&P X5

You do realize you are talking about 2 100th of an inch, right? That is an extremely small difference. You probably have that and more a variation when you load you ammo. I would not worry at all about 2/100" shorter brass.

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Freedom is never free!!
SWCA #3437

1.730 is the min spec for .223s

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Over thinking.

You must resize before measuring.

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USAF, 69-92
Vietnam, 72-73

You are correct, I had trouble finding the info on the SAAMI site and found mis-information elsewhere....

SAAMI tolerance for the .223 case length is 1.730"-1.760" (Sized case length)
Military spec tolerance for the 5.56x45 NATO case length is 1.750"-1.760"
The Lyman reloading handbook also specifies 1.750"-1.760" for the .223

However, finding the optimum cartridge overall length (COAL) for best grouping performance in your specific rifle is more important than minor case length variations.

I'm, by far, no expert. But when the "Can .223 cases be too short?" question comes up, in general, many folks respond with "Load 'em and shoot 'em."

I don't think I've ever read a report of a too-short case causing a problem. (Which is obviously very far from "There can't be a problem with a too-short case." I'm just reporting I've read a number of threads on this topic - and being too short has never come up as an issue.)

OR

Since this isn't the bench rest crowd I'll go along with load 'em and shoot 'em. They'll be longer soon, perhaps as soon as the expanding ball/plug runs out of the neck the next time.

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Lynnie, Professional Pest

There are only two considerations when it comes to case length. First, if it is at maximum then it must be trimmed.As others mentioned measure after sizing the case. There can be a significant difference between as-fired and as-sized, especially with bottle-neck rifle cases.

Second, will you be crimping the case? If so then they need to be trimmed to a relatively consistent length for consistent crimp pressure.

And, yes, you are overthinking this!

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Gunsmithing since 1961

I figured I was over thinking but case length effects case volume and could turn a load into a compressed load if it was pushing that point in the first place. Also if you keep the same COL then there is less bullet in the case. I am not going to worry about it I am shooting them these are not my bench rest loads.

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USN Retired/VN VET
M&P X5

I'm ok with .740-.760 . After .760 I will do a trim. I've seen new, once fired LC brass as long as .775 !

So? It should still be sized, measured, and trimmed.

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USAF, 69-92
Vietnam, 72-73

So? It should still be sized, measured, and trimmed if necessary. Whether it's once-fired or not, new or ancient, is irrelevant.

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USAF, 69-92
Vietnam, 72-73

Shoot them and they will grow a little.

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"He was kinda funny lookin'"

Be forewarned Federal cases are noted for having soft brass but that is not the whole story. Federal .223 cases "may" have thin flash hole webs and can have oversized primer pockets after the first firing. I buy once fired Lake City 5.56 cases because the flash hole web is thicker and military 5.56 brass is made harder in the base



I was given three five gallon buckets of .223/5.56 brass fired by our local police. And the Federal .223 brass was a pain to work with and approximately 25% ended up in my scrap brass bucket.

I bought pin gauges to check the primer pockets to find the oversized primer pockets.



And used a Lee depriming tool to check any questionable seated primers. If the primer moved with just finger pressure the case was scrapped.



If you are shooting a over gassed AR15 a tight primer pocket is required.

Having a consistent case length is one of the two most significant factors in achieving good grouping performance. The other is finding the optimum COAL to get the optimum bullet jump distance from the case to the start of the rifling in a specific rifle. Of course, consistency of bullet weight, case weight, and powder weight helps also, but not as much as the first two factors. This is where all the labor is for bench rest shooters - optimizing all these things. Some bench rest shooters use the same few cases over and over, reloading on the shooting bench as needed with precision hand tools, pre-weighed powder charges, and pre-weighed and balanced bullets. When I was doing bench rest shooting, I never went that far, but some did.

That is why my benchrest AR has a Bob Sled in it inst of a mag. To much jump distance with a mag length bullet.

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USN Retired/VN VET
M&P X5

FWIW, I've never encountered a loose primer pocket despite multiple loadings.

I don't have any trouble with almost any brass, and I'm using dozens of different headstamps, most of it scrounged from many different ranges..

The only exception, so far, is the "1K 03", made in Bosnia, that has tiny flash holes guaranteed to grab and break your decapping pin, even if supposedly "unbreakable."

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USAF, 69-92
Vietnam, 72-73

One other thing some BR shooters often do is to ream or drill flash holes to a uniform diameter, then de-burr the flash holes. I never felt that did much, but when you are trying to put all bullets into the same hole at 200 yards, every little bit helps. There is no end to the lengths to which some BR shooters will go in prepping their cases, including turning all case necks to a uniform wall thickness, cutting all primer pockets to a uniform depth and removing the corner radius, neck sizing only, etc.

I don't do BR shooting any more, but I do have a pretty good .223 varmint rifle that gives near-BR performance. I have a batch of about 50 Israeli military 5.56mm cases (TZZ headstamp) that produce significantly tighter groups than any others I have tried. I keep those separate for special occasions and neck size them only. I wish I had more of them. I know they have all been loaded over 30 times each, but I don't keep track.

I agree with your second point: The shorter the case the less bullet that is in the case.

But I'm not following your first point. I don't see how a shorter case impacts case volume. Case volume is impacted by the seating depth of the bullet - and the resulting COL. The bullet seating die will seat all bullets to the same COL - although obviously the shorter case will have less bullet in the neck per your point. But in that scenario the COL stays the same - and the base of the bullet is still at the same height - making the case volume the same from short case to longer case.

Am I seeing this wrong?

OR

P.S.: I guess I thought of another point. Rather than edit I'll just add it here. For empty cases, yes, a shorter chase will have less total volume than a longer case; e.g. a shorter case will be able to hold less water. However when talking case volume in terms of the volume/cavity the powder sits in after bullet seating, I contend that volume is constant when comparing bullet seated in short case to bullet seated in long case.

That would totally depend on seating depth of bullet. If larger and longer bullet seated to same coal then less volume in the case.
If same bullet ,and different length case then longer case equals more bullet inside case and less volume for powder. Shorter case would be less bullet, more powder volume available. This is not necessarily a constant though, or equal from case to case. Beginning volume minus displaced volume is different for each case and bullet, however slight the difference. Otherwise we would reload by volume not by weight. Many bench rest guys use volumetric measures of water to match cases for same dimensions and volume. They are trying to eliminate all differences to insure uniformity. Unless you are a stickler for absolute accuracy, these methods are not necessary..


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If case capacity is defined as the volume inside the case below the seated bullet, then for identical cases (except for neck length), identical bullets, and identical COALs, the neck length has no effect whatsoever upon case volume.

I'm not a master BR competition shooter. I'm strictly just an amatuer, and my only disciplin is service rifle High Power. Like i said i'm ok with .740 to .760 and not going to spend a lot of extra time holding brass to +/- .001". My time resources are more spent on the firing line advancing mechanics such as my npoa, respritory pause and trigger squeeze.