Case Length Tolerances for .223 ?

[fuegoslow]

I've been trying to find some tolerance ranges for .223 cases, like minimum/maximum lengths. I've read 1.750" is the desired length. But what if my cases are in the 1.735" - 1.749" range. Last time out, I picked up my brass for my first time reloading mission. I'm sure I picked up others used brass as well.

I'm using a Dillon 550 and wanted to de-prime a few cases. After doing this, I measured the cases and found them to be <1.750". Could it be I haven't adjusted the sizing die correctly? Am I expecting to find cases >1.750" in length after resizing? As I am new to reloading, I have yet to find a clear answer to the resizing aspect. I mean, we resize to stretch or compress the case? Or is it to reshape the shoulder/ neck area of the case. I'm ready to trim a few cases I just haven't had any that needed trimming ( my first few turned into 100) I'm waiting on a few tools so I haven't gone further than this in the reloading process. Any help will be appreciated.

[Santa Cruz Armory]

Full length sizing does just that, but it's not gonna stretch your brass that much, not all brass is gonna be long enough to trim. When you seat the bullet it will only go as deep as you have the seating die set, so it will be fine.

After you shoot it a few times you'll see that your brass will "grow", then you can trim it. I still chuck up each piece in the trimmer though to check.

[jandmtv]

i trim all of my .223 brass to 1.750" after each time of use. if they are shorter than 1.760" then dont worry about trimming them, its when they grow to and over 1.760" then you will have a problem if you dont trim.

[r08ert209cali]

get a siera reloading book they have all the specs on first page of each cal.
ditto on what the other guys said.multiple brand reloading books is quite usefull.

[30Cal]

Sizing squeezes the case back down. They'll get longer each time you fire them (sizing also contributes to this).

If you're full length resizing, you should have a case gage to correctly set the die so that the shoulder is being set back appropriately. The directions that come with the die which explain how to set it up are a half step better than completely useless.

[rksimple]

its when they grow to and over 1.760" then you will have a problem if you dont trim.

Not necessarily true. It depends on your chamber. I have a savage 12fv in 223 that has an extratction issue remedied by the use of long cases. How long? I've used cases up to 1.780" in length without any chambering issues and extraction is great. Its all dependant on how your chamber is.

[Chaingun]

I've been trying to find some tolerance ranges for .223 cases, like minimum/maximum lengths. I've read 1.750" is the desired length. But what if my cases are in the 1.735" - 1.749" range. Last time out, I picked up my brass for my first time reloading mission. I'm sure I picked up others used brass as well.

I'm using a Dillon 550 and wanted to de-prime a few cases. After doing this, I measured the cases and found them to be <1.750". Could it be I haven't adjusted the sizing die correctly? Am I expecting to find cases >1.750" in length after resizing? As I am new to reloading, I have yet to find a clear answer to the resizing aspect. I mean, we resize to stretch or compress the case? Or is it to reshape the shoulder/ neck area of the case. I'm ready to trim a few cases I just haven't had any that needed trimming ( my first few turned into 100) I'm waiting on a few tools so I haven't gone further than this in the reloading process. Any help will be appreciated.

Resizing the case will stretch the case. It also reshapes the neck area, the case itself and possibly the shoulder, to some degree. Some cases are too far gone for resizing.

Measure the case prior to resizing, and then after. You should see a few mils difference in length. Try this a few times. I've seen some cases after re-sizing with a length < 1.750", but they should all stretch and you will see a difference in length size. Most cases should exceed 1.750"

I'll assume you lubed the cases before resizing, or they will stick.

[ar15barrels]

Not necessarily true. It depends on your chamber. I have a savage 12fv in 223 that has an extratction issue remedied by the use of long cases. How long? I've used cases up to 1.780" in length without any chambering issues and extraction is great. Its all dependant on how your chamber is.

You just hit on something that probably 99% of shooters might never realize.
There are specs on case trim length, and then there are specific dimensions of a particular rifle.
The published specs are simply GUIDELINES that are supposed to be safe in ANY rifle made to the guidelines.
Now, MOST factory chambers will safely take cartridge cases considerably longer than the published specs.
I call these chambers "lawyer approved" as they are made longer to help keep pressures lower.
The unfortunate side-effect is reduced accuracy potential.

Sinclair sells a simple tool to measure YOUR chamber length.
Once you determine what your rifle can take, trim 0.010" to 0.015" shorter and be done with it.
If you have a chamber that's 0.060" longer than spec, I doubt you would ever need to trim your cases before they wear out.

[r08ert209cali]

great posts

You just hit on something that probably 99% of shooters might never realize.
There are specs on case trim length, and then there are specific dimensions of a particular rifle.
The published specs are simply GUIDELINES that are supposed to be safe in ANY rifle made to the guidelines.
Now, MOST factory chambers will safely take cartridge cases considerably longer than the published specs.
I call these chambers "lawyer approved" as they are made longer to help keep pressures lower.
The unfortunate side-effect is reduced accuracy potential.

Sinclair sells a simple tool to measure YOUR chamber length.
Once you determine what your rifle can take, trim 0.010" to 0.015" shorter and be done with it.
If you have a chamber that's 0.060" longer than spec, I doubt you would ever need to trim your cases before they wear out.

I always look forward to reading your post and value your opinions and factual statements that make since

[Jicko]

The factory rounds that I mainly shoot are AE223 and Federal XM193. For once fired, I found that most, if not ALL, of my batch of AE223 are under 1.760" while most, if not ALL, of my XM193 will be over 1.760".

Probably due to particular the factory rounds. So, you may just have a batch that you don't have to trim.

[C.G.]

The factory rounds that I mainly shoot are AE223 and Federal XM193. For once fired, I found that most, if not ALL, of my batch of AE223 are under 1.760" while most, if not ALL, of my XM193 will be over 1.760".

Probably due to particular the factory rounds. So, you may just have a batch that you don't have to trim.

I no longer fire factory rounds, but have kept the casings. Similar observation as yours, about half of the XM193 were over 1.760" whereas AE 223 was generally way short of 1.760"; Prvi Partizan was just under 1.760". This is after resizing, of course.

[ar15barrels]

I always look forward to reading your post and value your opinions and factual statements that make since

Thanks.

[ar15barrels]

The main value of trimming is consistent length, which aids in a consistent taper crimp.
Consistent crimp results in more consistent bullet pull.
Consistent bullet pull results in more consistent powder igntion.
Consistent powder ignition results in improved accuracy.

The actual length you choose is not significant as long as it agrees with the length of your chamber.

[Metal God]

ZOMBIE THREAD

Yeah I know but rather then start a new one I thought I'd ask here .

I'm looking for the minimum length you can trim a 5.56 case . I did not see it answered yet in this thread . I see alot of max length but no minimum .

My Hornady book says 1.750 is what you should trim your case to . Is this just a recommendation or is it law . I bought a lee manual case trimmer for 223 and it cuts great and consistant .Problem is it cuts the case to 1.745 Is that .005 make the case to short ? Can you cut the case to 1.720 ? what is the minimum case lenth for a 5.56 case ? I assume at some point you wont have enough neck to hold the bullet or your min OAL will be to short cus of the bullet seating depth .

[pakk]

How does a longer case length increase accuracy?

Wouldn't a longer case result in higher pressure chamber pressure? Is there enough increased pressure here to be concerned about?