FL sizing my .223 brass causes it to lengthen by 6/1000s as compared to what it measured immediately before resizing? Is that about normal? Add the 3/1000s it grows from just firing the brass and that means I have to trim brass after every firing, since I FL size after every firing. If the brass would only grow by 3/1000s from sizing, I wouldn't have to trim it every time. Will partial FL Sizing cut down on my 6/1000s growth? Thanks.
how much to FL Sizing increase .223 brass length
- Thread starter CJK8
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Waywatcher
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How much are you bumping the shoulder back? If you are over-resizing, that could be the problem. Where is the shoulder on your fired brass?
243winxb
Member
Not normal for me to have to trim after each FL sizing. You could buy a RCBS X die. This die will keep the brass from growing.
Funshooter45
Member
Different cartridges tend to grow at different rates when FL sized. And then different rifles with different headspace conditions also add to the variability. Your growth is more than any of my rifles, but I wouldn't say it is entirely abnormal. The growth of 0.003" just from firing tells me that you do have more headspace than what I observe in my rifles, but it's not alarming.
But yeah, learn how to do partial length resizing and it will cut back on the amount of case stretching to some degree.
You don't say whether your .223 is a bolt action or semi-auto. If it's an auto, then I don't really know the issues on partial length resizing. Proper feeding might be an issue there.
But yeah, learn how to do partial length resizing and it will cut back on the amount of case stretching to some degree.
You don't say whether your .223 is a bolt action or semi-auto. If it's an auto, then I don't really know the issues on partial length resizing. Proper feeding might be an issue there.
gearheadpyro
Member
It depends on your die and your brass. The expander ball inside the die is usually what stretches the brass, and if you've got thick military brass you may be pulling on that a bit more than normal. Try putting just a smidge of lube on the inside of the case neck and see if that changes things. Make sure to get the lube off once you've resized it (I run mine through the tumbler again after f/l sizing).
A headspace gauge will help you determine how much you are moving the shoulder and if it is excessive. For my ar I try to push the shoulder back .003-.005". Bolt guns I shoot for 0.002-0.003" bump.
A headspace gauge will help you determine how much you are moving the shoulder and if it is excessive. For my ar I try to push the shoulder back .003-.005". Bolt guns I shoot for 0.002-0.003" bump.
i check the length of my cases after every firing in a go-no-go length gauge and trim only the ones that do not fit. I routinely trim 25% to 33% of the cases processed. This includes 223 Remington fired in ARs.
So, I expect my brass is lengthening about 0.002" to 0.003" inches per firing from the length before firing.
Note, cases usually get shorter when fired.
So, I expect my brass is lengthening about 0.002" to 0.003" inches per firing from the length before firing.
Note, cases usually get shorter when fired.
Measure it after sizing and before loading. Shoot it, clean it, resize it, and measure it again. Whatever that difference is will be how much it grew. I doubt it will be .006. Regardless, the stretching will slow with each firing/sizing.
ranger335v
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" I am just following the die instructions and wondering if 6/1000s of growth from sizing alone is normal."
Let's just say it isn't abnormal.
The amount of case growth can vary quite a bit, mostly by the diameter of the chamber and the diameter of the FL die, especially if we jam the fired cases as far into the sizer as we can get it to go. Resizing so the sized shoulder is at the same point or a thou less as the fired shoulder point will reduce but not always stop such growth.
Following factory die adjustment 'instructions' certainly makes ammo that will go BANG! But, it rarely makes ammo that actually fits the chamber; 'custom fitted ammo' is a lot of what reloading should be about.
Let's just say it isn't abnormal.
The amount of case growth can vary quite a bit, mostly by the diameter of the chamber and the diameter of the FL die, especially if we jam the fired cases as far into the sizer as we can get it to go. Resizing so the sized shoulder is at the same point or a thou less as the fired shoulder point will reduce but not always stop such growth.
Following factory die adjustment 'instructions' certainly makes ammo that will go BANG! But, it rarely makes ammo that actually fits the chamber; 'custom fitted ammo' is a lot of what reloading should be about.
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That is what I did. Started at 1.752" before loading. Shot, cleaned, and resized it then measures 1.761". .003" was from firing and .006" was from resizing. This is out of my bolt action. Out of my mini 14, the brass does shorten after firing but then gets back to about the pre-fired length after resizing.
Waywatcher
Member
If you want to know if it's normal, you're going to need a tool to measure shoulder bump. Hornady and RCBS both make one.
I like the RCBS one I have, factory unfired brass measures at 0.000, fired brass from my AR measures about 0.002; I resize it to -0.001 to 0.000 to be safe.
Without a tool there's no way to know, it'd be a shot in the dark. But bumping the shoulder back too far will definitely lengthen your brass everytime. With the tool you can make informed adjustments to your resizing die (screw it in or out) so it resizes just what you need, not too little and not too much.
I like the RCBS one I have, factory unfired brass measures at 0.000, fired brass from my AR measures about 0.002; I resize it to -0.001 to 0.000 to be safe.
Without a tool there's no way to know, it'd be a shot in the dark. But bumping the shoulder back too far will definitely lengthen your brass everytime. With the tool you can make informed adjustments to your resizing die (screw it in or out) so it resizes just what you need, not too little and not too much.
243winxb
Member
To work the brass less, set you FL sizing die so you get a crush fit when closing the bolt. When you set your FL die, start with .010" between shell holder & die. Use a feeler gauge. Or make shims from a soda can, use 2 for a thickness of about .009" Put hole in shim for decapper pin. Check fit in the chamber. If bolt will not close, try .008" or less till bolt closes. Lube the inside of the case neck.
How do I determine that? When I pull the brass out of the die it does catch a bit. I talked to a few people and they say that is normal.
I played around with partial FL resizing tonight. I tried with backing the die out about .050". About 2/3rds of the neck was sized. I assume that is normal since I am backing off the die?? The brass still grew about .005" from the resizing. So, I backed the die out about a total of .100". Less than half of the neck was sized. The brass only grew by about .002", however, which is what I was hoping for. But, since not much of the neck was sized I was wondering if I would have enough/appropriate neck tension. Both cases chambered fine, which didn't surprise me since the brass was once fired out of the same gun. Any thoughts are appreciated. Thanks.
Hondo 60
Member
Something sure doesn't seem right there.
I have to trim after the first firing & then again after about the 3rd or 4th firing.
I trim to 1.750 & trim again after they stretch to 1.757 or more.
(for an AR-15)
I have to trim after the first firing & then again after about the 3rd or 4th firing.
I trim to 1.750 & trim again after they stretch to 1.757 or more.
(for an AR-15)
Cases get longer when sized. They get skinnier from the die sizing them, and the shoulder gets bumped back a little, unless you have the seater backed off too much, and so the case must get longer. That is why we always trim after sizing.
If you start with sized case that is 1.750, fire it, and then size it, it will be longer. How much is determined by how soft the brass is and how much pressure it was under. Trim if needed. Do it again.
If you want to know if the decapper is pulling necks forward, size with out it to see. If you lube the inside of the neck it shouldn't. Just roll a nylon brush over a lube pad and brush the neck, or dip the neck in mica or graphite. A carbide expander ball helps as well.
Decappers were designed by gremlins. They are a good reason to use a bushing type die, whether a full length one or a neck sizer only. Bottom line though is the standard dies with decappers used properly work well enough most times.
sugarmaker
Member
On my current .223 setup I get about .001-.002" growth due to sizing when I use a lee collet followed by a redding body die, and I don't have to lube inside the necks. The redding is setting the shoulder back about .004-.005", for highpower competition in an AR. The .001" tolerance I get is mostly due to my measurement tools.
I get all of that, but I am trying to figure out how to get more than one firing before needing to trim again without going to necksizing. Several people I have talked to and Hondo above say they get about 3 fires before needing to trim. I'd like to get there too if I can. Two firings would be nice. Like I said above, I get .003" of growth from just firing and another .006" from sizing for a total of .009" of growth.
I do lube the inside of the necks. I'll try it with taking out the decapper.
Back to my question about partial FL resizing from yesterday. When done properly, does the entire length of the neck not resize like I was explaining? Thanks.
I have been reading how people partial size. They usually say back the die off 1/2 or one full turn and then size a case. They then say the bolt probably will not close and to slowly adjust the die and size until the bolt will close without resistance. That clearly wasn't my experience. My bolt closed fine. Should I be alarmed? Thanks.
If the entire neck is not sized then the shoulder is not being bumped. That could make it hard to chamber becasue the shoulder is pushed forward until the die shoulder meets it and pushes it back. Might not. You just have to try it.
If it was brass fired in a shorter tighter chamber it could be a loose fit to your chamber unsized. If it was fired in your chamber, it may be tight or may be loose, depending on the pressure you fired it at and how soft/hard the brass is.
I guess I am doing a bad job of describing this, because you do not seem to understand what is going on.
If it was brass fired in a shorter tighter chamber it could be a loose fit to your chamber unsized. If it was fired in your chamber, it may be tight or may be loose, depending on the pressure you fired it at and how soft/hard the brass is.
I guess I am doing a bad job of describing this, because you do not seem to understand what is going on.
OK. I understand that. What I did yesterday did not bump the shoulder since the neck was not fully sized. However, I don't think the shoulder was pushed forward either because the brass chambered fine and the bolt closed easily. This was brass fired out of the same gun.
I guess I was getting confused in thinking that the shoulder SHOULD HAVE pushed forward and I should not have been able to close the bolt based on what I was reading. But it seeems that is not always the case.
So, it looks like I am stuck with a total of .009" of growth each firing and resizing...meaning I have to trim after each firing. I get these results with various loads and mixed brass. I wish I knew why my brass grew so much compared to others.
Thanks.
Just because the brass chambered doesn't mean the shoulder wasn't moved forward a little bit. You have no idea unless you measure it somehow. They sell tools to do that. Some are simple and cheap, and some are more complicated and expensive.
1. Free and easy. I made this for .35 Remington
2. Cheap and easy. Designed for bullets, but will work on shoulders.
http://www.sinclairintl.com/.aspx/pid=34262/Product/Sinclair-Hex-Style-Bullet-Comparators
Mid priced and works well by all accounts.
3. http://www.midwayusa.com/viewProduct/?productnumber=477756
http://yarchive.net/gun/ammo/precision_resizing.html
4. Very nice, and pricier.
http://www.larrywillis.com/
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If the shoulder moved forward a bit, doesn't that mean the bolt should have been a little difficult to close since the case was fired out of the same gun? In any event, I don't think that has anything to do with keeping my brass from growing so much from sizing...unles I am wrong. Thanks.
We've danced all around the problem.... back to the basics for the bolt gun:
1. Having removed the extractor (and ejector if req'd) from the bolt, will a fired case rechamber w/o any resistance at all ?
IF YES:
2A. How many successive pieces of scotch (magic)* tape can you put onto to the case bottom to finally get some "feel" to bolt closure? (Magic tape is ~0.002" thick)
3A. Once you get any "feel" at all, measure the case headspace/shoulder position with whatever comparator system you have and subtract 0.002" (that last piece of tape). That measurement is your target from now on when using a full-length resizing die. (Lock the die to that setting and it will minimize case growth from stretching in the future.).
IF NO:
Full length resize in stages (and 1/8 turn per stage) until it just does chamber with no feel. Turn the die back to very near the previous turn position/test/re-adjust barely to chamber and lock it. That is your sizing setting from now on to minimize stretch.
1. Having removed the extractor (and ejector if req'd) from the bolt, will a fired case rechamber w/o any resistance at all ?
IF YES:
2A. How many successive pieces of scotch (magic)* tape can you put onto to the case bottom to finally get some "feel" to bolt closure? (Magic tape is ~0.002" thick)
3A. Once you get any "feel" at all, measure the case headspace/shoulder position with whatever comparator system you have and subtract 0.002" (that last piece of tape). That measurement is your target from now on when using a full-length resizing die. (Lock the die to that setting and it will minimize case growth from stretching in the future.).
IF NO:
Full length resize in stages (and 1/8 turn per stage) until it just does chamber with no feel. Turn the die back to very near the previous turn position/test/re-adjust barely to chamber and lock it. That is your sizing setting from now on to minimize stretch.
chrome_austex
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Trimming your brass to 1.745 should be ok, right? .. and it would get you closer to 2 shots per trim?
I think most people just resize the necks in bolt guns... I know I did with my bolt gun, and boy did loads last a lot longer between trimmings.
Rounds shot through my AR probably grow close to that much after firing and full-length resizing. I seem to have to trim about every other firing, but I've never measured the exact growth.
I think most people just resize the necks in bolt guns... I know I did with my bolt gun, and boy did loads last a lot longer between trimmings.
Rounds shot through my AR probably grow close to that much after firing and full-length resizing. I seem to have to trim about every other firing, but I've never measured the exact growth.
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