223 fired cases .....too much pressure?

locknload45

locknload45

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Hi Guys
(sorry guys tried to re due the pics)
can you please have a look at these pics, do I have a pressure problem here?
is this normal? the rings just above the shoulder
am I doing something really wrong?

ztH7XvP.jpg




these are 2nd time fired american eagle (fedral brass) notice the ring just above the shoulders
I have 30 rounds like this

I shoot them out of my M4gery only, which is chambered in 556 with no problems
cycling or firing and fairly accurate too

I reloaded them to this : 55 grn FMJBT (Lake city )bullet ,20 GRNS of IMR 4198,Winchester SR primers
cases are trimmed to 1.75 slight crimp seated at 2.20 pretty close to factory american eagle rounds
using a Lee classic turret Press,Lee perfect powder measure and Hornady digital scale

heres a once fired case that I bought bulk just to show the difference I'm talking about

http://i.imgur.com/8S2wj7T.jpg?1?2478
 
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Likely a .223 case, pressure forming to a 5.56 chamber...




223vs556.jpg
 

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Likely a .223 case, pressure forming to a 5.56 chamber...
Click to expand...
thats what I thought, thanks for the diagram
doesn't show any difference in the neck diameter though, unless my noric is oversized chamber wise

Only way to know is to measure the brass
Click to expand...
I will do that see if there is a difference
just woundered if anyone has seen that before
 
Don't shoot .223 in a 5.56 chamber? Or do, just don't expect to reload the brass... I think there are enough tolerance differences in the mouth of the case and shoulder to cause some deforming under extreme pressure, but I'm no expert.
 
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seems strange so many guys reload 223 can't find anything on it, gotta be more with 556 chambers out there
I know the 556 brass is thicker walled forsure
I also know there are two types of Fedral brass on the headstamp large FC and small FC
maybe I better back off on the charge this batch see what happens
 
Gummo said:
Don't shoot .223 in a 5.56 chamber? Or do, just don't expect to reload the brass... I think there are enough tolerance differences in the mouth of the case and shoulder to cause some deforming under extreme pressure, but I'm no exert.
Click to expand...

What I mean is that this is twice fired brass. OP has fired it once, or acquired it from someone else how has, and then (presumably) passed it through a full length resizing die before reloading it.

The FL die is going to set the measurements of the case according to some spec-- in this case it's .223, because (AFAIK) there is no such thing as a 5.56 die. So if his problem were as simple as '.223 being fire-formed in a 5.56 chamber' then nobody would ever be able to reload for 5.56 without seeing these effects on their fired brass :)
 
Gummo said:
Don't shoot .223 in a 5.56 chamber? Or do, just don't expect to reload the brass... I think there are enough tolerance differences in the mouth of the case and shoulder to cause some deforming under extreme pressure, but I'm no exert.
Click to expand...

The only real difference between the .223 and 5.56 are the throats, military chambers are always larger in diameter and headspace.

223_zps6248614d.jpg


Now to add more fuel to the fire, my stock factory Savage .223 has a longer throat than any of my AR15 rifles, meaning it doesn't have a SAAMI short throat.

I load .223 cases all the time and shoot them from my AR15 rifles "without any problem". We loaded 30-06 cases and shoot them from our 03 Springfields and M1 Garand rifles. We load .308 cases and shoot them in our M14/M1A rifles. So we can also shoot .223 cases in our AR15 rifles, end of story.

If you fire a factory loaded .223 in a AR15 rifle the chamber pressure will be approximately 5,000 psi lower than normal because of the longer throat.

barnes-pressure_zps9347fe41.jpg
 
locknload45 said:
seems strange so many guys reload 223 can't find anything on it, gotta be more with 556 chambers out there
I know the 556 brass is thicker walled forsure :HR:

I also know there are two types of Federal brass on the headstamp large FC and small FC
maybe I better back off on the charge this batch see what happens
Click to expand...

Actually our American 5.56 military Lake City cases have more case capacity than commercial cases and weigh less than .223 cases.

casecap_zps3f8bb2c9.jpg


223-556weight_zps3566d29a.jpg
 
The cases fired in your rifle look like they have marks from rough chamber reamer, buy a box of factory loaded ammunition and see if you still have the ring at the top of the shoulder. If not then you might have a sizing problem, YOU need to do more detective work and the rest of us are just guessing about your problem.
 
bigedp51 said:
The cases fired in your rifle look like they have marks from rough chamber reamer, buy a box of factory loaded ammunition and see if you still have the ring at the top of the shoulder. If not then you might have a sizing problem, YOU need to do more detective work and the rest of us are just guessing about your problem.
Click to expand...

I would go along with this before a chamber problem. From the OPs post, this seems to be only happening on the second reload. To me that indicates he is setting his shoulders back to much and as the case expands to fill the chamber you have the original shoulder marks as well as the stretched out marks.
 
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