.223 Case Length

[jeepman_psu]

Hi all, I am new to reloading and have a question about trimming brass. I am currently reloading some .223 brass. I mistakenly measured a few of the cases before sizing and they were below 1.76 so I than proceeded to de-prime and resize. I than primmed approx 100 rounds. After doing this I realized that I was supposed to measure the case length after I resized. I am now measure between 1.765 and 1.775. I am not sure what to do here. Is 1.76 the max length or is it 1.760? Can I trim the brass even though it has a live primer in it? I really don't want to waste 100 rounds, but most importantly I don't want to damage my gun!

 

[xmanpike]

1.76 and 1.760 are the same length. I would stay inside the maximum lenth

 

[Mags]

Deprime the brass and trim your cases. You can reuse your primers if you are careful, don't worry they won't go off when pushing them out from the top. I say you must deprime because my case trimmer reaches through the flash hole so it really depends on your setup.

 

[jeepman_psu]

They are not the same length. 1.76 only goes out to two decimal places meaning that 1.767 is fine, where as 1.760 means it is out of spec. It is all a decimal place accuracy that I am asking about.

 

[JDGray]

Trim to length is 1.750, 1.760 is max. My Lee trimmer is used without primers in the case, don't know any other system. The hand crank style cutters, may work primed

 

[Mags]

No Jeepman 1.76 is the same as 1.760 as the "0" is in the thousandths place meaning "0" thousandths so if you have "0" thousandths you don't have a thousandth of anything. So 1.760 is 1 inch and 76 hundreth. Math class is now dismissed.

 

[JDGray]

Pronounced "One inch, seven hundred, sixty thousands" English 101 is done

 

[Canuck-IL]

1.76 only goes out to two decimal places meaning that 1.767 is fine, where as 1.760 means it is out of spec

So 1.767, which is longer than 1.760 is FINE(??) but the shorter 1.760 is out of spec - think before typing!
1.76 is the same as 1.760, is the same as 1.7600, is the same ... etc.
Yes, they need to be trimmed - those are way too long.
Trimming w the primer in? - on my Hornady w a manual crank, I probably would - likely no greater risk than depriming them all.
/Bryan

 

[Ol` Joe]

Remember in the future resize BEFORE measuring case lgt. Brass always grows the most from resizing.
Lots of cases have been fine prior to sizing, then found to be too long.

 

[WNTFW]

Jeepman,
Make a list of steps in the proper order. Put check boxes next to the task and check off as done. It sound overly simple but it really gives you a clear path to follow. It will force you to slow down when you are ready to fly.

A case gauge for .223 in a AR is a must.

Stuff happens, at least you realized what you did. I get that in certain trades the decimal place also is used to express tolerance if not called out.

Rework is no fun and no profit.

 

[Seedtick]

jeepman_psu They are not the same length. 1.76 only goes out to two decimal places meaning that 1.767 is fine, where as 1.760 means it is out of spec. It is all a decimal place accuracy that I am asking about.

jeepman, I think I understand your question and if I do - yes, the third decimal place matters. I don't have a manual handy but from the other answers it appears that 1.760" is max so anything longer (1.761+) needs to be trimmed. And you can poke out a live primer and reuse it just use a steady pressure and all will be well. You should already be wearing safety glasses.

You did good by catching this and even better by asking about it.

ST

 

[Eb1]

They are not the same length. 1.76 only goes out to two decimal places meaning that 1.767 is fine, where as 1.760 means it is out of spec. It is all a decimal place accuracy that I am asking about.

Is this what is wrong with the country today?

 

[jeepman_psu]

I am sick of people thinking that I am stupid for what I asked. I was trying to ask about tolerances. I do CAD design every day and it does make a difference when you put 1.76 or 1.760 on a drawing to send to a machine shop because you are telling them the number of decimal places to be accurate to, I believe it is called significant figures (don't lecture me on math 101). When they view that drawing and do the design they only have to accurately measure to two decimal places. So if they are manually running a milling machine it could read 1.763 and that would be ok because they are only required to be accurate to two decimal places. However, if I would of labeled the drawing 1.760 they would of been required to be accurate to three decimal places therefore making 1.763 incorrect. I hope that I have cleared myself up because while I know there is not actual difference in the number itself when you work in the environment I do decimal places can sometimes be the difference between a tight fit and a loose fit and that makes all the difference in the world.

 

[flashhole]

jeepman - your assessment is correct. You are not stupid. One might argue about rounding errors but your assessment is still correct.

It doesn't change the fact that you need to trim your brass. Just chalk this one up to learning experience and know you are not the first one to do this. When I deprime a live primer I wear glasses and drape a dishtowel over the die. Just apply slow constant pressure and you'll be fine. You might also consider dropping the decapper assembly down further than normal so you aren't resizing the case again.

 

[wastedimage]

The max case length is 1.760 so you will need to trim. On my RBCS trim pro trimming a primed round is ok (though i would be extra careful and be damn sure you have the primer fully seated). As mentioned above just depends on your setup.

 

[JDGray]

Reloading is a game of thousands, not tenths, and in some rifles, the extra .007 wont matter. My Lee cutter takes my brass down to 1.755, and some of the brass I trimmed today were in the 1.770 range, and shot out of my AR15 with a Wilde chamber without issue. I cant believe that your brass will give you any issues, unless your shooting a match chambered bolt gun.

 

[Roccobro]

Possum hollow trimmer. Doesn't matter if primed or not.

Justin

 

[rcmodel]

The only trimmer I know of that it does matter is the Lee.
It index's off a pin through the primer flash hole.

Every other trimer I can think of index's off a stop collar on the cutter shaft or some other method that is non-dependent on havine no primer in place.

rc

 

[Seedtick]

Yeah, Sig Figs

jeepman_psu - I do CAD design every day and it does make a difference when you put 1.76 or 1.760 on a drawing to send to a machine shop because you are telling them the number of decimal places to be accurate to ....

I thought I understood your question and now I know why. For the better part of 25 years I was the machinist who got those drawings. (well I wasn't the machinist specifically and no they weren't really your drawings but ah, well, you know what I, ooh never mind) Although I never had any (.xx) tolerances most of them were (.xxx). But it was the (.xxxx) tolerances that made for long days. :banghead:

ST

 

[kelbro]

Sinclair has a chamber length gauge for about $7 that will let you know what your max length really is ( http://www.sinclairintl.com/product/11241/Case-Gauges-Headspace-Tools ). I have them for every caliber that I load for. Nearly every chamber that I have measured is longer than the max that manuals print. Without this gauge, you are wasting time trimming your brass.

 

[JDGray]

Without this gauge, you are wasting time trimming your brass.

For accuracy, trimming makes sense, and is nessesary for consistant crimps, if crimping.

 

[lgbloader]

Jeepman,

Best thing to do is take a deep breath, relax and follow all the good advise given to you here.

What kind of trimmer do you have? This will determine what you need to do next.

Let us know if you need anything else.

LGB

 

[Walkalong]

But it was the (.xxxx) tolerances that made for long days.

Yea, that separates the real machinists from the casual micrometer user. .0001 is tough to do consistently.

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Lots of good advise in this thread. As already posted:

Best to size the brass prior to sizing.

Trim to 1.750 after sizing. (Or at least no more than 1.760, which is the max trim length, but most folks do 1.750, which is the minimum trim length)

OK, you didn't size first before checking, and now you have some sized and primed cases that are too long. No real big deal. Yes, you can trim with the primers in. I would blow them out with compressed air real good after wards to make sure any brass shavings are gone. Other than that, no worries.

Next time size first, and you will save yourself the extra trouble.

 

[Walkalong]

What kind of trimmer do you have? This will determine what you need to do next.

Good point lgbloader. I forgot about that.

The collet holder type trimmers like RCBS, Redding, Forster and others make will work with primed cases. The Wilson trimmer will work. The Possum Hollow trimmer will work.

The only trimmer I know of that it does matter is the Lee.

Same here.

 

[jeepman_psu]

Thank you everyone for the great advice I really appreciate it. I will be picking up a trimmer hopefully today to take care of this. I wanted to get the Possum Hollow because it seems like a pretty slick tool, but everyone seems to have them back ordered. My biggest concern at this point is if the primer is not perfectly seated and will cause problems and be dangerous, but I plan on checking them and giving ones that seem a little suspect an extra seat in the press, but most seem pretty good from a first look. I noticed that on the RCBS there was a indentation on the shell holder end that made it look like there was no way that the primer could even come in contact with anything so I might look into that as well.