Just finished polishing up a bunch of one fired 223 cases and sit down to see which ones needed trimmed. Trim length for 223 Rem is 1.750" but a bunch of these cases are 1.735 to 1.740. Appears the head stamp is F C. are these cases to short to use? Just wondering about seating 55gr bullets at the COL I am using if they will seat deep enough. Don

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USN Retired/VN VET
M&P X5

I'm not an expert reloader but I load .223 and I've loaded and shot short cases. From multiple sources on this and other boards I've been told shooting short cases is just fine.

OR

Just to note that you should size the case before measuring and trimming but you may have already sized them. They grow in length a few thousandths when sized. I've seen no problems loading cases that length but wouldn't want to use shorter cases.

Size 'em, measure 'em, and reload them. Even if they are too short, they will grow in a couple of loadings. You're not shooting bench rest anyway.

Michiganscott is correct - clean, size, measure and trim. There is a reason you have a .010 variance in trim to length. There are factors beyond the shooters control that will affect groups in a bench gun much less sportier shooting. Rule of thumb is a bullet seated as deep or deeper than diameter of bullet is good to go. You will be fine.

Dial up your caliper & look how little 0.005" is, even 0.010", pretty insignificant. If you are crimping, you may find a diff between 1.250" & 1.235", but not much.

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NRA Cert. Inst. IDPA CSO

They are fine to shoot a tad short, less than trim to length. I always measure after sizing.

Are these new brass or did you buy or pick up used brass.

When new and full sized they will grow more at first and then slow down on their growth rate/

Don't forget to check the inside of all your brass with a bent paper clip or dental pick like tool to check for Incipient Case Head Separation.

Look it up

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Still Running Against the Wind

Per SAAMI the case length specification for 223/5.56 is 1.760 +0.00 / -0.02, so your cases at 1.740 are within tolerance. As for those at 1.735, like the others I wouldn't worry about it. A case this much below the minimum would only have a theoretical effect on accuracy that I don't think any human shooter could observe even at 1000 yards.

These all started out as once fired indoor range brass as up to the change this month you had to buy all AR ammo from the range and people that don't reload have to toss it in the range bucket. about 90% of these are PMC head stamps and the rest FC. The FC were all the short ones and I did not like that ammo anyway. About 3 MOA groups is all it would do where as my reloads will do a MOA or less. Best being .554" @ 100yds. Except able out of a stock MP15. Well back to processing brass. Don

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USN Retired/VN VET
M&P X5

Short cases are fine. HOWEVER, if you are shooting for best grouping consistency, all cases should be trimmed to substantially identical lengths, even if that length is shorter than maximum. And some also sort cases by weight.

Every year at qualification for the AR I grab a box of brass at clean up time. My department shoots FC. I deprime with a universal deprime die then clean and resize. Probably 95% of the brass will still be short in the 1.743 area. Since I'm working with a thousand or so pieces I usually try to sort them in batches of close lengths. As stated above they will grow with each firing. They work fine for range use. I use the FC pickups coupled with the Hornady 55 gr fmjbt bullet with crimp groove. I'll crimp these with the Lee Factory crimp die as OAL of case is not a factor.

If I'm shooting for accuracy or a DCM match I'll use quality brass trimmed at minimum length and 69 gr Sierra's. Since the Sierras don't have a crimp groove I put a very light taper crimp on them with the Dillon taper crimp die. Just enough to flatten the case mouth against the bullet.

I went ahead and set a standard of +or- .005 from 1.750 for my 55 gr range loads. They will after a few firings end up trimmed to 1.750. I only am going to load my 69gr Match Kings in my Lupua cases and those will be trimmed right to 1.750. There was only 12 FC cases out of 350 PMC, Win and Fc brass that was shorted then 1.745 so I just set those aside. If the Zombies show up I might load them. Don

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USN Retired/VN VET
M&P X5

SAAMI spec is 1.760 +0/-.03, so you are good to go down to 1.730

^^^ Not in the PDF file I downloaded from SAAMI.

Attached Files

ANSI-SAAMI .223 Remington.pdf (102.6 KB, 62 views)

Are you looking at the "Unless Otherwise Noted" figure or the actual dimension on the drawing? http://www.saami.org/pubresources/cc...0Remington.pdf

It is good we have SAAMi specs as ammo manufactures have a standard to go by so their ammo will shoot in all of are guns but if I want to shoot tight groups then I need a tighter spec. Even when shooting steel I want to hit the center of the plate not just ring the bell. Don

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USN Retired/VN VET
M&P X5

How about a newer version?

http://www.saami.org/pubresources/cc...0Remington.pdf

OOOps I see W maximus already posted it.

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Still Running Against the Wind

Don, I don't think that you'll EVER be able to observe any effect on accuracy of trim lengths that are this close. My hunch is you would have to be shooting at 1000 yards and the 223/5.56 is NOT a 1000 yard caliber. It's too prone to wind effects and there is that pesky supersonic/subsonic transition somewhere around 600-750 yards.

BTW, Accuracy Tweaks I've found to be a waste of time are sorting bullets by weight, sorting cases by weight, sorting cases by volume, or getting all obsessive about bullets being loaded perfectly concentric. These measures may have some observable effect for 1000 yard precision benchrest shooters but for the rest of us holding a breath mint in out mouth while cycling the press will be just as effective.

What I would suggest you spend your efforts on is experimenting with a small selection set of Quality bullets, two or 3 powders, and work up what particular combination and charge level produces the best accuracy in your rifle. Because I've found from real world experience that using a quality bullet loaded to the proper charge level with a good powder are the most critical factors for getting good, accurate ammunition. BTW, I am talking about sub 3/10 MOA accuracy, not 1 MOA loads. I will also note that while it requires hand weighing each charge I have yet to find any bullet that doesn't work very well with Varget, so when I want to hit a 1/2 inch sticker at 100 yards I reach for Varget to build the load to do that.

I have my supplies down to this.
3 powders
Varget
CFE 223
IMR 4198
2 bullets
Hornady 55gr V-Max
Sierra 69gr HPBT Match King

I will not be shooting competition just challenging myself. For me this is a lot more fun then loading up a thousand 1 MOA rounds and going out and making noise. You can only sit at a outdoor range with their restriction and shoot so many groups before it gets a little boring. Not to mention expensive on retirement income. I miss the days when I lived in Iowa and could shoot fox, ground squirrels, and Jack rabbits. Armadillos here in NE Florida at 10yds or less just is not the same. Don

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USN Retired/VN VET
M&P X5