AR-15 Range Brass

[Old Navy]

There is snow everywhere. Can't get into my BR range so I thought I would get the AR out and work up some 80 loads. My bins of brass were a mess. I decided to sort everything by head space. When I bought my AR years ago I bought 1000 pulled down LC67 brass. I used it for working up loads and serious target practice. I used this brass to get my chamber length. The brass fired in my gun measures 1.461 to 1.462". I gathered up every thing else I have picked up or had given to me and went to measuring. I was surprised to find a lot of it measured 1.455-1.456. What is the deal with this? I reloaded a few of these short cases and fired them. The shoot ok but do not fire form to my chamber. They come out short and black all the way to the rim. I have looked at all the reamer specs for the various chambers. The head space looks to be the same. What am I missing? Thanks. Frank

 

[jonbearman]

If they are black and sooted,more than likely your load is not hot enough in this cold season. I would put out your load so we can comment on how to avoid this.Some cases are longer due to manufacturing requirement,it is usually due to what type of crimp they are using during the war.I have measured and noticed the same thing over the years so I trim them to 1.450 and go.

 

[Old Navy]

Jon, the 1.455" is from the base of the case to the point on the bottom of the shoulder where the head space is measured. Later! Frank

 

[Catfish]

My guess is that your loads are to lite to expand the brass into the chamber and it is not sealing it.

 

[CPorter]

When my cases start getting black down the shoulder it's past time to anneal the neck

 

[jhord]

As to headspace being the same or nearly the same for different reamer profiles, that is not the case. Example, my RRA National Match upper will blow cases out to ~ the 1.460 that you mention. My Fulton/Criterion barrel blows them about .005" shorter. The RRA is a .223 Wylde (I believe) and the Criterion is some sort of long throat tight .223. The difference is so great, that even after full-length sizing RRA fired brass in a small base die, it is still a tight fit on the Criterion. Now as to why your range brass is not ff to the longer chamber, +1 to what everyone has said. Light loads more than likely.

 

[243winxb]

Re: AR-15 Range Brass 223/5.56

 

[Old Navy]

As to headspace being the same or nearly the same for different reamer profiles, that is not the case. Example, my RRA National Match upper will blow cases out to ~ the 1.460 that you mention. My Fulton/Criterion barrel blows them about .005" shorter. The RRA is a .223 Wylde (I believe) and the Criterion is some sort of long throat tight .223. The difference is so great, that even after full-length sizing RRA fired brass in a small base die, it is still a tight fit on the Criterion.

Thanks for the info guys. I was pretty sure the range brass that I picked up was fired in a short chamber. I just couldn't find one specked out that short anywhere on the net. The blackened brass I mentioned was fired in the Wylde chamber on my RRA varmint EOP. The cases were approximately .010 too short. No way in hell to fire form that much without jamming the bullet in the lands. I have way too much throat for that. Since I have a lot of brass I will just set it
aside. Thanks again. Frank

 

[treeman]

i agree with cporter you need to anneal diffrence in brass hardness can make a diffrence on case length(headspace). casses that have been annealed will come out of the chamber longer than work hardened casses. they will also come out of the sizeing die shorter( i.e. headspace)due to spring back. annealed casses will also seal at the neck at lower chamber pressure keeping soot from going back into the chamber. lots of variables.
good luck and good shooting

 

[treeman]

in response to what 243winxb says I would like to see some one prove that a fireing pin strike could shorten headspace.006" there is no way even on an annealed case. if you dont beleive that put an annealed, primed case in without the bolt slamming forward pop the primer then measure headspace it won't change. the bolt can move headspace but not much. by the way 243winxb I'm not trying to start a verbal brawl or anything like that but I have expermented with this when I shot xtc matches.
treeman

 

[243winxb]

Different Firearms = Different Results?

KAZ22 [Member]

4/22/2012 12:54:03 PM EST

OK, I did the shoulder set back test(cases with fired primer) on three of my RP cases that I annealed. Set back was .006 So, I loaded up three of my once fired/resized LC cases with factory only annealing and the results were the same at .006 Tested on my INNOVATIVE TECH gauge. Now perhaps tommorrow I will test this first lot at the range.

243winxb [Member]

4/22/2012 11:53:47 AM EST

http://findarticles.com/p/articles/mi_m0BQY/is_6_56/ai_n56225198/ Good Luck. My results have not been good using a torch. My thoughts on the subject. >
Annealing is best left to the brass manufacturers , as it needs specialized equipment to do it correctly. A misfire can be caused by improper annealing. When the shoulder becomes to soft, the firing pin strike can set back the shoulder. If the round fires, the brass expands, leaving no evidence of set back. I was shooting 223 Federal brass on its 6th loading. Having cracked necks, i decided that annealing might get a few more firings out of the brass. Even tho 40 years ago, annealing did not work on some 243win brass, making the necks to soft. The 223 misfire would not fire on the 2nd strike from the firing pin. At home, measurements show the shoulder was set back .014" when measureing to the datum line. L.E. Wilson's case gage shows the brass head below the lowest step. All loaded rounds had been gaged before firing. More testing was needed. Took 3 annealed brass with used primers and chambered them. After 2 strikes with the firing pin, shoulder set back was between .010" & .012" The used primer already had the firing pin dent in them, so the blow from the pin was not as great as new primers. The primer involved in the misfire was placed in a different non-annealed piece of brass. It did fire on the 2nd firing pin strike. A total of 4 hits on the primer, till it fired. I feel the primer may have been damaged from the first 2 misfires. Savage Axis bolt action 223 less than a year old. 722 rounds fired. Loaded with IMR4198-20.5gr-CCI400-Win. 55gr FMJBT-Federal brass-RCBS Dies made in 2010. There are Hornady Annealing Kits available & Tempilstik & Tempilaq that may help. But when you overheat the brass, there is no way to fix it. 3/28/12

http://www.ar15.com/archive/topic.html?b=6&f=42&t=369231

 

[bigedp51]

in response to what 243winxb says I would like to see some one prove that a fireing pin strike could shorten headspace.006" there is no way even on an annealed case. if you dont beleive that put an annealed, primed case in without the bolt slamming forward pop the primer then measure headspace it won't change. the bolt can move headspace but not much. by the way 243winxb I'm not trying to start a verbal brawl or anything like that but I have expermented with this when I shot xtc matches.
treeman

The reloading manuals warn you not to use cases that were used for reduced loads again for full power loads because of "short" cartridge case headspace. The firing pin will shorten headspace but I have never seen it decrease by more than .001 with each firing pin hit. I took photos of this using a RCBS Precision Mic and .308 cases in another posting. I do "NOT" agree with what 243winxb stated about the .006 to .014 shorter cases above. If this were true every reloader would be having case head separations the second time they fired their cases.

Read the link below and the section on "PRESSURE, EXTREMELY SIMPLIFIED". Gas port pressure can effect fired case length and the amount of soot on the case.

http://www.radomski.us/njhp/cart_tech.htm

I was surprised to find a lot of it measured 1.455-1.456. What is the deal with this?

Minimum headspace or GO is 1.4636, how many AR chambers are .006 below minimum headspace? How many cases fired in a AR that you find on the ground are going to be "shorter" than a GO gauge?

97% of all errors are human errors and only 3% are mechanical failures.
Meaning 243winxb's #9 above or human error!

I have three five gallon buckets of .223/5.65 range pickup brass that were fired by our local police swat teams and picked up within an hour of firing. None of these cases varied by more than .003 in case headspace length and NONE were shorter than GO or minimum headspace.

My gauges do not lie or tell ferry tales.

 

[jhord]

It's not really the range brass being "short," it's the fact that a RRA chamber is big enough to throw a cat through.

BTW, what powder are you using? That might also be a factor.

Thanks for the info guys. I was pretty sure the range brass that I picked up was fired in a short chamber. I just couldn't find one specked out that short anywhere on the net.

 

[bigedp51]

It's not really the range brass being "short," it's the fact that a RRA chamber is big enough to throw a cat through.

I understand what your saying BUT even the Wilde chamber is only a "cat hair" bigger.

And FYI Lake City brass is harder than commercial cases.

 

[243winxb]

Brass shorter after firing. M16A1

The brass got shorter, head to datum, when fired in my M16A1 Colt using full power loads. The case body right behind the shoulder got larger by .005" The expanding of the body outward pulled the neck/shoulder back. The Colt chamber is bigger then most. When you FL size, everything is pushed forward/long again. Edit Add. The difference in extractors has an effect also. Rem 700 & M16 have less slop then the Savage.

 

[Old Navy]

I didn't think this would turn into a who's is bigger match. Just wanted to know what kind of chamber dumped short head space cases. I am not a novice re-loader. Been at it since 67. On my second BRX barrel right now. I should not have even mentioned black cases. Just FYI the load was an 80 Berger over 23.5 grains of Varget with CCI-450s. Fired this same load with my 1.462" cases yesterday. It went .508" @100 with just a dirty neck. I sat here watching football the last couple days measuring/sorting brass. I actually found some clear down to 1.451/1.452". Since this is worth near nothing .223 brass it went in the scrap can. lapua would be a different story. Thanks. Frank

 

[bigedp51]

Frank Blum

I have two Savage rifles and belong to the "Brotherhood of the Barrel Nut".

"SOME" of these barrel "nuts" use a new unfired case as a headspace gauge to set their headspace on their Savage rifles. If the case is shorter than normal, their next posting is asking "WHY" their full length resized cases won't fit in their chamber.

Some people will build an AR15 from parts kits and it might be possible to screw up the headspace setting on an AR15.

I have a bolt action Savage .223 with a 26 inch heavy barrel and two AR15s and have never seen your problem when the cases are full length resized.

A custom Wylde .223/5.56 chamber has the largest diameter of any of these chambers and "might" get shorter "BUT" with 55,000 psi making it conform to the chamber dimensions I just don't see the cartridge headspace getting smaller.

Sometimes on a gas gun the case ends up longer than the chamber when ejected but shorter to me is an oddity I have never seen after full length resizing. You could even use headspace control shims under your dies if needed and make your short cases "longer".