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]

Originally Posted by jandmtv

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]

Originally Posted by 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.

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]

Originally Posted by rksimple

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]

Originally Posted by ar15barrels

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.]

Originally Posted by 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.

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]

Originally Posted by r08ert209cali

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?

[Enfield47]

I noticed all of my Federal .223 and most 5.56 ammo was less than the trim length that was published too. I asked about it here in this forum and found that is typical of Federal brass to be a little shorter after resizing. So no worries, it will work just fine (mine did), but it's good you noticed the difference and questioned it.

[ar15barrels]

Originally Posted by Enfield47

I asked about it here in this forum and found that is typical of Federal brass to be a little shorter after resizing.

Actually, most rifle brass will be LONGER in case length after re-sizing than after it was fired.
This is because during firing, the case expands outwards and stretches in the body.
Then the case gets squeezed back down to diameter during sizing.
When sizing, the extra brass from the expansion of firing all extrudes up to the neck in the sizing die.

[Nessal]

I didn't read the thread so I apologized if it's been covered. But I measured many 5.56 and .223 factory chambers and I've came to the conclusion that you would be hard pressed to get so close to the end of the chamber and not notice the long *** neck. Custom barrels are another story.

[Enfield47]

Is it just once fired Federal brass that tends to be shorter? Out of about 150 or so rounds of Federal and LC brass almost none of my Federal was long enough to trim, and probably less than half the LC brass was trimmed. I'm guessing the more it is fired the more trimming that has to be done.

[ar15barrels]

Originally Posted by Enfield47

I'm guessing the more it is fired the more trimming that has to be done.

That is correct.

[beenawhile]

Originally Posted by r08ert209cali

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

X2 :thumbup:

[LynnJr]

MetalGod
There is no minimum length you trim brass too.It can be as short as you like.That said when you shorten it way up you have less grip on your bullets and during heavy recoil this could affect your seating depth.There is no accuracy to be gained by shortening brass way shorter than saami spec.

[JagerDog]

Originally Posted by 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 .

You can adjust your trimmer. RTFM. Min is 0.010 under nominal. Max is 0.010 over nominal. This is to fit all rifles.

[ShadowX]

You do not have to resize if its not over the 1.750 length. However, make sure you deburr all your cases whether it is the correct length or not. You can feel the difference on the cases that are deburred vs the cases with the rough original surfaces as you seat the bullets. The cases with a nice clean chamfer would seat very smoothly. The ones with a rough edge would require a larger force to start and you would have copper/brass shavings on the contact areas. I make sure I deburr all my cases after a resize.

I just get one of the Lyman or RCBS hand tools and go to home depot to find a hex standoff that fits. I think its a #4-40 thread hex that happens to also fit a standard drill perfectly. Just install the cutter onto the hex extension and use a drill. You can go through a lot of cases very quickly and cleanly in comparison to a manual tool. It makes deburring more fun.

[ar15barrels]

Originally Posted by ShadowX

You do not have to resize TRIM if its not over the 1.750 length.

Fixed.

[pakk]

Originally Posted by LynnJr

There is no accuracy to be gained by shortening brass way shorter than saami spec.

Is there any to be gained by lengthening it?

[LynnJr]

The gains you would see from longer brass are minimal or theoretical at best.

Most accuracy shooters prefer long necks but the 300 Win mag has a short neck and has a reputation that it shoots very well.

The specs you read about are put into place so Joe Public doesn't hurt himself
and the manufacturers don't get sued.

The longer neck should reduce fouling and throat wear because the high pressure gases get centered up before going into the barrel.To test that theory out hold a funnel in one hand a pour a gallon of water through it.You should get a nice even stream coming out the end.This would represent the long brass.

Now cut the same funnel off right were it slims down and the same gallon of water out of it will have a larger pattern to it right were it exits the funnel.Once the water continues to fall it will once again become more streamlined.This would represent the shorter barrel

If the water was hot gases it would foul more and eat up the throat faster in theory

[pakk]

Originally Posted by LynnJr

The gains you would see from longer brass are minimal or theoretical at best.

Most accuracy shooters prefer long necks but the 300 Win mag has a short neck and has a reputation that it shoots very well.

The specs you read about are put into place so Joe Public doesn't hurt himself
and the manufacturers don't get sued.

The longer neck should reduce fouling and throat wear because the high pressure gases get centered up before going into the barrel.To test that theory out hold a funnel in one hand a pour a gallon of water through it.You should get a nice even stream coming out the end.This would represent the long brass.

Now cut the same funnel off right were it slims down and the same gallon of water out of it will have a larger pattern to it.This would represent the shorter barrel

If the water was hot gases it would foul more and eat up the throat faster in theory

Thank you.

With 223 and using the sinclair chamber length gauge, could someone increase the case length enough to raise the pressures enough to get in to trouble

[LynnJr]

Factory chambers tend to be very long and the guys reaming the barrel take into account not everybody does everything right.The chamber can be cast with cerrosafe and measured so your trim to length can be increased to its optimum length.http://www.youtube.com/watch?v=DByaASz_HNk

Once you have your guns chamber length you can trim 0.010 from that number and not worry about it.If you stay on top of the trim length you can adjust it to less clearance you just don't want it butting up against the throat.

In all honesty if the cases fit easily into the chamber it is tough to get into trouble.The pressure will rise if the neck running into the throat crimps the bullet but you would feel that as hard bolt closing.Couple that with todays book loads which are not as hot as they use to be and its hard to get into pressures that will hurt you.Most gun blow ups are wrong powder or excessive powder and bore obstructions.If your shooting a 270 and a 308 and mix them up you will get into trouble.

Try measuring the end of a neck then re-inserting the case back into the same gun.If the neck gets constricted or rolls over the cases are too long and need trimming.You won't have any problems loading using the Sinclair Tools.

[FLIGHT762]

Originally Posted by ar15barrels

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.

This is ver true, most reloaders do not actually measure the length of their chamber. For years, I would get OCD over keeping my 308 Win. brass trimmed under 2.015" SAAMI recommended maximum and would get nervous when getting close to 2.015".

I bought one of the Sinclair chamber length gauges and measured two of my L/R bolt guns. The Factory Remington chamber length was 2.045" and the custom gun was 2.040". I actually laughed out loud when I got the measurements.