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Empty resized case won't chamber

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ilmonster

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Aug 5, 2012
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I have a bunch of once fired PMC .223 Rem cases. They were fired in my BCM AR in 5.56//223. I thought since they are .223 cases, I could resize them in my Forster FL resizing die and they should fit my Rem 700 .223 that I have and reload for (I don't reload for the BCM AR). So, I deprimed the PMC cases tonight and then FL resized them. I bumped the shoulders back to 1.459" which is where I bumped back my Hornady cases I've reloaded before. Most measured at around 1.468" after firing in the BCM AR which is quite a bit longer than the cases fired in my Rem 700. Guessing that is because of the AR's 5.56 chamber. I thought I would try and chamber the empty resized PMC case in the Rem 700 just to make sure it would fit. I could slide the bolt forward, but couldn't rotate it closed? I took a number of my twice fired and once reloaded Hornady empty cases (which have only been fired in the Rem 700) and tried to chamber them, and they all chambered fine. I measured the OAL of the empty case, diameter, etc. and the PMC and Hornady cases measure within a thou of each other.

Question is, why won't these PMC cases originally fired in the AR (but FL resized tonight in a .223 die) allow me to rotate the bolt closed? Is this a moot point as these aren't yet topped by a bullet. I don't want to load up 50 rounds and have none of them chamber in the rifle. Thanks!
 
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A measurement is out somewhere. Try a small base die which sizes to minimum saami specs. Take a case and bump the shoulders back another couple thou. That will cause the rest of the case to squeeze down a bit more too and see if it chambers. If it does get to measureing where. Or coat a case in sharpie and then try to chamber and see where it's rubbing.
 
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Thanks for the reply's! I like the sharpie idea and will try that tonight. I will also take a few of the non-chambering cases and bump the shoulders back another thou or two. If that doesn't work, I can take my once reloaded (twice fired) Hornady cases that have only been fired in the Rem 700 and get to loading those for the weekend.

One question though. I have seen the small base dies at the store. How do those differ from the regular Forster .223 dies?
 
Don't go out and buy a S/B die. First try the sharpie. You likely are not bumping the shoulders back far enough on the AR fired brass. You may need to turn your die in the press a bit more. A 1/8th turn of the die will move it down another .009". You may only need a small turn a 1/16 or less. I had this happen to me many years ago. All I needed was a slight turn more and cases chambered in my 700 and all other AR's. I've been loading for AR-15's and 700 223 bolt guns since the early 1970's. Chambering issues were all cured by turning the die into the press slightly more.

Most of the time, you don't need a S/B die. Sometimes they're needed when sizing fired brass from Military M-240's or M-249's.
 
I agree that the rest should be checked before buying another die.

But to answer on the differences in a small base vs other full length- The sammi spec is essentially a range. Im going to use trim lengths as an example because its what I know off the top of my head for a 223. 1.760-.030 which means that anything that falls in the range from 1.730-1.760 would be inside of the saami spec. Obviously the case web diameters will be a much small/finer spec than the brass trim length. If the AR chamber allows for stuff at the maximum end of that range (1.760) and the bolt is on the lower end (1.730) then the larger ar stuff wont fit into the bolt by the .030. The same relation ship goes for each dimension of the case, case head diameters, should locations/headspace and so on down the line.

If ar is large and the bolt is small and the die is somewhere in the middle then you wont be able to use that middling die to force the brass down small enough after brass spring back etc to fit the small bolt chamber. In that situation a small base die would be required which would push the brass back down to the minimums spec to fit in even the smallest side of things.

Something to keep in mind though is that unless you require it the small base will result in working the case much more than necessary. Its typically ar fiored brass that require them as compared to bolts. The ar will generally be more gratuitous in its dimensions so that anything that goes in it will go bang, not to mention that gas issues can lead to premature extraction which means its getting pulled out of the chamber before its fully expanded and then contracting again which allows it to expand just a slight bit more. That bit more expansion will require a bit more to size it back down. Just like how your brass measured 1.468 vs 1.459. I bet you ill find a difference in the diameters along the body somewhere as well.

So to summarize, small base puts it at the minimum side of saami spec and the others can potentially fall anywhere within that spec. I myself only use brass in one gun and do not share it among others as it can lead to issues like this or making compromises such as getting the brass small enough to fit in the bolt makes it way smaller than necessary for the ar which leads to even more working of the case.
 
sharpie is $1.25 last time i checked at walgreens. new die is $35. sharpie first and then go from there. it may be something completely different from all the suggestions as well, i highly doubt it but you never know when it comes to brass from what i have learned. ask me how i got into neck turning. freaking 260 rem.
 
I'm thinking the issue is occurring at the shoulder.

Compare a factory case's shoulder height and diameter against the resized case.

Also check overall case length at the case mouth. if that case is too long, it could cause a pressure excursion, I've seen that blow up a gun with the .308.

Greg
 
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Different brass springs back differently. Just because your die sizes Hornady brass to your chamber doesn't mean it will size PMC brass to the same tolerance. It may be as simple as resetting your existing die to account for the spring back of the PMC brass. I have not worked with Hornady brass in .223 but have found that PMC is pretty similar to Lake City for sizing.
 
Anneal your brass and put them thru a SB die. A semi chamber is different to a bolt gun.
 
You are basically partial full length sizing the brass. (Maybe)
if you don't have the die set up to push the shoulder back, it will actually stretch a case.

Basically you you are neck sizing with a full length die. This stretches the case...
 
Have you trimmed the brass? One thing I've found is that AR's have lots of wiggle room for case length to the point that you almost never need to trim brass. Bolt guns are much tighter in that dimension. Maybe your AR is stretching the shit out of the brass and it's too long.
 
I full length sized the brass and them trimmed it with a Lee Trim tool. I shot some reloaded Black Hills brass this past weekend and will compare it's twice fired dimensions with the AR fired PMC brass.
 
You could pick up a wilson cartridge case gauge and that would help tell you what is going on.
 
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I had a similar problem and even though the once fired (from an AR) brass would slip easily into the Wilson gauge, it would not chamber in my really tight chambered target rifle (SAMMI min chamber) even after sizing. The sharpie showed it was the base dimension that was ever so slightly too large. I'm quite sure the AR was larger there for feed reliability. I simply screwed the die in a bit more to resize more of the base and the problem was gone. After that, I only used brass fired from that target rifle for reloads for that rifle. Now I generally keep brass rifle specific - but brass from that target rifle WILL fit any other.
 
Milo,

You are better off seating your bullets out longer in the 6xc. Just seat them long enough so that the full diameter of the bullet is beyond the neck/shoulder junction.
 
OP,

You need a tool that will measure your case length indexing on the shoulder. Chances are you need to bump the shoulder back farther. An RCBS mic or Hornady gauge with inserts will work,

It is unlikely that you would need a small base die for brass used in a SAMMI spec'd chamber. Factory chambers are pretty generous.
 
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DaveM said:
Milo,

You are better off seating your bullets out longer in the 6xc. Just seat them long enough so that the full diameter of the bullet is beyond the neck/shoulder junction.
Click to expand...

It is, we throated it out, empty sized brass was giving me fits, no use to powder them at that point.
 
I’m just in the process of setting my dies up but I’m having the exact same problem, except I have pmc brass fired from my 700 that chambers perfect. The pmc fired from my ar, when resized does not fit in my rem 700. Everything measures the same, except the neck measures .001-2” bigger on the ar brass after resizing. I haven’t received my bushings yet for my Redding fl sizing die, like I said I’m just starting to set them up. I colored the cartridges in sharpie, ran them through a couple times, and no wear marks on them. Could it be the neck size that’s just not showing up? Everything else measures identical.
Any ideas?
Thanks
 
Do the sized cases fully drop in and drop out of the chamber under gravity? If yes, its probably shoulder needs to be bumped a little more.

If they hang up, need to be pushed in or stick when tilting up the rifle, then it's probably the body or base that's still bloated from the AR chamber being bigger than the 700 chamber.
 
smoothy8500 said:
Do the sized cases fully drop in and drop out of the chamber under gravity? If yes, its probably shoulder needs to be bumped a little more.

If they hang up, need to be pushed in or stick when tilting up the rifle, then it's probably the body or base that's still bloated from the AR chamber being bigger than the 700 chamber.
Click to expand...
smoothy8500 said:
Do the sized cases fully drop in and drop out of the chamber under gravity? If yes, its probably shoulder needs to be bumped a little more.

If they hang up, need to be pushed in or stick when tilting up the rifle, then it's probably the body or base that's still bloated from the AR chamber being bigger than the 700 chamber.
Click to expand...
I just tried, they were hanging up and needed pushed in. I set them to go deeper in the die (I have a ton of this brass so I don’t care if I mess it up) and when I’m bumped back approx 15 thousandths ( 1.447”, 10 thousands more than a factory round) they go in and hang up just ever so slightly. Is it ok to bump back this much or slightly more, then fire form to this gun, and then bump .002 from then on out? I don’t care about brass life for the most part, Iv got a lot. or do they sell some sort of body sizing die that leaves the shoulder alone that I could run through before I run it through my die I have now?
 
smoothy8500 said:
No, not a good thing to do. At this point you ruled out the shoulder, it's a "Small Base die needed" issue due to a tight chamber.
Click to expand...
So I picked up a Redding small base body die, but I’m having the same issues, I have to bump the shoulder back an excessive amount to get the brass to freely chamber. If I just set it back to what my gun likes with once fired brass from itself (1.459”) or factory (1.457”) it’s still tight to chamber. Any ideas? It’s like I need a die that only sizes the body and doesn’t touch the neck or shoulder so I can go all the way down, and then size the neck and shoulder on my regular fl sizing die in the next step.
 
03machstock said:
So I picked up a Redding small base body die, but I’m having the same issues, I have to bump the shoulder back an excessive amount to get the brass to freely chamber. If I just set it back to what my gun likes with once fired brass from itself (1.459”) or factory (1.457”) it’s still tight to chamber. Any ideas? It’s like I need a die that only sizes the body and doesn’t touch the neck or shoulder so I can go all the way down, and then size the neck and shoulder on my regular fl sizing die in the next step.
Click to expand...
Are you having this problem with virgin brass or 1x fired from your AR? Referring to your post (#23), says your pmc brass chambers into your 700 with no problem however your brass fired from an AR is stuck - is that correct?

If so, acquire brass dedicated to your 700 and run that; keep your AR brass separate.
 
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My guess is neck of you still haven't gotten your bushing. When no marks showed up on your sharpie test you could have eliminated the small base right there, there would have been scuffs on the brass body.

Quick test, size 3 pieces of brass and grind off the necks to the junction, deburr and see how she does.

Edit: measure 5 fired cases out of whatever gun you are trying to fit them in and get the average base to shoulder and size .003 to .005 less than that... not that crazy .015"
 
....I would suggest one of these to check your cases, gives you MORE visual information to work with. They can also be used to check sized cases BEFORE you even load them to save on your time, primers, powder and bullets.

sheridanengineering.com

308 WIN Ammunition Gauge

Choose between SLOTTED or NON-SLOTTED. AMMUNITION GAUGES are uniquely designed to check loaded ammunition, giving you the ability to check your factory ammunition or reloads against a spec chamber. The gauge is machined to the SAAMI minimum chamber spec for the 308 WIN caliber. This…
sheridanengineering.com sheridanengineering.com
 
r.tenorio671 said:
....I would suggest one of these to check your cases, gives you MORE visual information to work with.
Click to expand...
I would say it gives LESS useable information. Only proves that your cases either fit or don't fit the gauge.

Is your chamber tighter or looser? If so, where? The gauge may help, but it's not definitive.
 
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Get a case headspace gauge and chamber gauges. I had a similar issue and the gauges helped me sort it out.
 
I'm assuming not where it's. 223, but any swageing, or crimp removal 1st? What was your process after firing untill now for this brass?
 
An ar normally has more room in the chamber to account for heat, high rate of fire dirty field conditions ect.

I've loaded a lot of pmc and no problems except the occasional off center primer flash hole. (Toss it ) it was pretty reliable and reasonably accurate.

I would just set up separate die sets and keep that brass segregated.

You only want to bump ar brass about .004 max if all your ar's have the same size of fired brass, I load for five all with the same chambers within one thousands on the bump. If only your one ar you can get away with less than 004 less dirt or mag dumps.

You can get sub moa rounds with a 003-004 bump, to my supprise.

If I remember right pmc was 7-8 thousands short on the headspace on factory rounds.

I was going to build a precision 223 bolt gun till I started getting 1/2 moa from a new ar barrel.
Have hit 3/8 a couple times with it.

My only setback is loading to mag lenght as far as I'm concerned.
 
smoothy8500 said:
I would say it gives LESS useable information. Only proves that your cases either fit or don't fit the gauge.

Is your chamber tighter or looser? If so, where? The gauge may help, but it's not definitive.
Click to expand...
....per their website, the Sheridan's are cut with SAAMI spec reamers. IF your brass or loaded ammo fit in the Sheridan gauge, it will fit in a compliant SAAMI spec chamber. The utility of the gauge is it ALLOWS one to see if the shoulder bump, trim length or web sizing is the culprit in a SINGLE glance. A casing that is too long (trim length) or insufficient shoulder bump can cause the casing rim to stick out proud in the enclosed type gauges, but it's not possible to see which of the 3 possible causes it could be (or a combination of the 3 possible causes).
 
nn8734 said:
Are you having this problem with virgin brass or 1x fired from your AR? Referring to your post (#23), says your pmc brass chambers into your 700 with no problem however your brass fired from an AR is stuck - is that correct?

If so, acquire brass dedicated to your 700 and run that; keep your AR brass separate.
Click to expand...
Yes, that is correct. I have a 5 gallon bucket full of the pmc 1x fired from ar’s that I was trying to use. I was trying to avoid buying brass or shooting a bunch of factory ammo through my rem.700, although it looks like I may need to.

FUNCTIONAL said:
My guess is neck of you still haven't gotten your bushing. When no marks showed up on your sharpie test you could have eliminated the small base right there, there would have been scuffs on the brass body.

Quick test, size 3 pieces of brass and grind off the necks to the junction, deburr and see how she does.

Edit: measure 5 fired cases out of whatever gun you are trying to fit them in and get the average base to shoulder and size .003 to .005 less than that... not that crazy .015"
Click to expand...
My fired cases out of my Remington 700 ( the gun I’m trying to load for) measure 1.461” base to shoulder. When those cases are bumped and FL sized to 1.459” they fit perfectly. I’ll try the test you are talking about.

GTOJOSH said:
I'm assuming not where it's. 223, but any swageing, or crimp removal 1st? What was your process after firing untill now for this brass?
Click to expand...
My process was just clean the brass in my vibratory case cleaner, lube them, and try to set up my dies. The .223 pmc brass doesn’t have crimped primers, if that’s the crimp your referring to.
 
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r.tenorio671 said:
....per their website, the Sheridan's are cut with SAAMI spec reamers. IF your brass or loaded ammo fit in the Sheridan gauge, it will fit in a compliant SAAMI spec chamber. The utility of the gauge is it ALLOWS one to see if the shoulder bump, trim length or web sizing is the culprit in a SINGLE glance. A casing that is too long (trim length) or insufficient shoulder bump can cause the casing rim to stick out proud in the enclosed type gauges, but it's not possible to see which of the 3 possible causes it could be (or a combination of the 3 possible causes).
Click to expand...
Or you could just measure and get real data as it relates to your chamber and not to some arbitrary spec that means nothing to your personal conditions.

Notice damn near every thread about brass or fitting also has the people trying to use a dumbass “saami” gauge?
 
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SO, what did the "Sharpie" or "Magic Marker" case show you ?
good brass ie;1x shouldn't be hard to find, get a couple hundred and set aside for your 700 only.try to find a Lee collet die for these 223 brass.
 
spife7980 said:
Or you could just measure and get real data as it relates to your chamber and not to some arbitrary spec that means nothing to your personal conditions.

Notice damn near every thread about brass or fitting also has the people trying to use a dumbass “saami” gauge?
Click to expand...

I don't think I've ever recommended case gages on this forum but I have a bunch and they are convenient. They don't replace any of the other measuring tools but it sure beats dragging the rifle out to check economy 308 and 556 brass. I don't think case gages would help the original poster or the necro-bumper but case gages do have their place.
 
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Baddog 0302 said:
SO, what did the "Sharpie" or "Magic Marker" case show you ?
good brass ie;1x shouldn't be hard to find, get a couple hundred and set aside for your 700 only.try to find a Lee collet die for these 223 brass.
Click to expand...
The cases looked like I just colored them, no marks on them at all. But Maby I’ll try a dry erase marker so it will rub away easier? Your comment of magic marker just clicked in my head.
 
What are the base and shoulder diameters of fired cases out of your 700 chamber? What are those numbers from your sized PMC brass?
 
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Sounds like textbook shoulder not set back enough
 
Do a chamber cast, or bring it to a gunsmith that can do it for you. That way you will have the correct dimensions and can tell if the chamber is out of spec.
 
918v said:
What do you have against measuring things?
Click to expand...
Nothing, but with the wide variation with reamers and specs you are not able to truely compare it to anything. If these were chambers he had cut and had the specs for it then that can be used to compare the chamber and brass. Only way to reliably do that now is cast the chamber (as mentioned above).
 
ilmonster said:
Most measured at around 1.468" after firing in the BCM AR which is quite a bit longer than the cases fired in my Rem 700.
Click to expand...
Just an fyi I measured hundreds of random 223 brass from range pickup brass and my ar's the average and 99 % of it measures 1.4635 - 1.464 and that relates directly to spec go gauge.

I had one ar that was measuring short so I removed that bolt and replaced it.

Your ar is + 004 thousands over average.

I still have the bolt I replaced because it put out brass that was 1.4615 that ? matches your bolt gun?

That would not fix a base sizing problem though.

Just a thought.
 
FUNCTIONAL said:
Nothing, but with the wide variation with reamers and specs you are not able to truely compare it to anything. If these were chambers he had cut and had the specs for it then that can be used to compare the chamber and brass. Only way to reliably do that now is cast the chamber (as mentioned above).
Click to expand...

No.

If you measure the case length, the shoulder length, the base and shoulder diameters of a fired and sized case the problem becomes immediately apparent. Casting the chamber is not required.
 
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