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223 case length

17K views 11 replies 7 participants last post by  itdoeseasy 
#1 ·
I picked up a bag of once fired Lake City 223 brass, resized 'em, and miked 'em and they are about 1.78". Book shows Trim length 1.750" and 1.760 max. I can't imagine the brass started out at close to 1.76 to end up at 1.78, anyone else notice really long brass cases? Looks like I've got a lot of case trimming ahead of me.

JJones458
 
#2 ·
Pick a number....any number, between 1.740 - 1.760 and stick with it.
I find that I trim after every shooting as I prefer all my brass to be the same, or as close to the same as possible.(1.755)
some brass will expand more than others (ie: thin brass stretches like heck) The important thing (for accuracy) is to keep them all the same.
 
#3 ·
I too trim after every shooting. It is all easy with a drill set up. Cut the length, put in the primer hole cleaner and do that. But before I do all that,, after I knock out the old primer I usually put them in a tumbler to clean them. You can see any defects: cracks: a whole lot easier witht them clean....
 
#5 ·
I have seen it all over the place...it is not a problem in a rack rifle since military rifles are typically a bit long on headspace..but if you are shooting a bolt gun or one of the new AR based platforms then you need to pay attention to OL.....I generally take my once fired brass and (if shooting in my bolt gun)trim it, neck size and turnthe neck to clean it up. From then on it grows little in my bolt gun...now...

In the AR platform...my son has one with a tight chamber and i use a small base die each time and trim to fit...shortens life but prevents chambering issues....the rifle shoots and feeds fine....just costs me in case life.....

I keep mine separate since my bolt gun rounds are seated a bit long to account for the lead in my chamber.....makes my M77 almost like a video game....great for shooting bottle caps at 200 yards....something not possible with factory or bulk ammo.
 
#6 ·
I'm wondering how factory ammunition can be loaded in oversize (too long) cases. Seems that liability issues as well as just good loading practices would dictate otherwise. It seems unlikely that cases could start out at even close to 1.76 (max case length) and "grow" to 1.78 (what I'm seeing with once fired, cleaned, resized Lake City Brass). Are Mil Specs different than what I'm finding in the published reloading manuals? Don't AR chambers need cases that are under the max length? What am I missing here?
 
#7 ·
Wonder what they were before the resizing operation?
Resizing has a tendency to push the shoulder back(good thing) causing the case neck to stretch. Is it possible you are overworking it a little?
Then again I am fairly new at all this so I may be way off with my advice/observations.
 
#8 ·
Well...the mil spec brass is 5.56 mm......the commercial cylinders are .223...there is a difference...while slight...engineering slack might cause a problem. my ruger is a .223.....and I prepare the brass just for it...my son's AR is a hybrid...aftermarket lower, with an h bar upper and a 26 inch stainless barrel....cut to 5.56 specs....
 
#10 ·
223 case length...

Most of the 223 chambers and chambering reamers I have measured go 1.780 to 1.790. If a full length sized case chambers easily, with no sign of scraping between the end of the case and the end of the chamber, it is IMHO good to go. If slight resistance is felt on bolt closing and one is not sure if it is due to case length, there is still any easy means for checking.... Mark the end of case with dykem, felt tip pen, etc and check the chambered cases for scrape marks. If none are evident then you still have chamber length to work with. I had a Sako 223 with a light sporter barrel which showed great accuracy with cases ranging from 1.74 to 1.78. This was with non crimped rounds of course. If crimping loaded rounds I would stay within .010 maximum case length variance. I don't argue that consistant case length is a good thing. That said, I think the volume of loading being done, accuracy level of the firearm being used etc, should relate to how zealous one is with case trimming.
 
#12 · (Edited)
I just acquired 6000 pieces of 5.56 LC brass. This was all once-fired. I have only loaded but some .5.56 in the past and never for an AR. I have never had trouble with trim length on once-fired brass. We loaded quite a few today. I did not bother to trim the brass, did not think about it even. I had loaded about 10 and test-fired them with no problems previous to this exercise. I subsequently tried a number of these, hand cycling them through three different 5.56 chamber ARs. About every 5th one will stick like crazy in all three.

I went back and measured the length and they all fall between 1.765 and 1.775 for the most part.

These are crimped with a Lee Factory Crimp Die.

How do I know if these are sticking for this reason, for sure?

IDE
 
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