Fired Brass Can't be Re-Sized

You might try one of these Lee ''Undersizers'' in 45acp. .003'' undersize should help.;) Remove the decapper rod too. No messy lube needed either. The sizer is CARBIDEo_O
I use a Dillon carbide die and RCBS Ammomaster press, and the brass is difficult to resize. Only tried a Redding small base die once, and stuck the brass in the die but was able to remove the brass and learned my lesson.
 
So I have to ask for an update. Did you ever get any satisfaction at all out of LaRue or did they just outright refuse to stand up to their deceptive advertising and marketing info.
 
I just got a factory new AR10 chambered in 7.62 NATO (308Win). My first 7.62 auto loader. I am a reloader. I have been doing it for 30 years now. I have been an active Bench Rest, PRS, and IDPA competitor and, reload for all those disciplines. I also reload all my hunting ammo. So, I am pretty sure I know what I am doing and am confident my equipment is up to and exceeds par.

Using a box of new Lapua 308 Win brass I had on hand, I loaded up several "ladders" that consisted of 168SMK, 175SMK, 175VLD-H, and 178ELD-X. All respectable bullets. All were loaded using various weights of Varget power, and GM210M primers. All top shelf components. None of the loads were anywhere near max. In most, at least two full grains short. No over pressure signs.

I also shot a couple of factory loads, Hornady Black 168AMAX, and Federal Gold Medal Match. All reloads and factory ammo functioned flawlessly except the factory Fed GMM. It was not powerful enough to strip the next round from the magazine and closed on an empty chamber. "CLICK". The GMM did function flawlessly with the gun suppressed but the groups were terrible. All other groups were near or under 1 MOA for 5 shots. The best was the 178ELD-X that grouped .62" and clocked 2500 fps. It's a 20" barrel.

To the point: All cases except for the Hornady case will not go through my resizing dies. Even with the Hornady I really had to stand on the lever to get them sized. When I measured the fired cases, all dimensions were around a full .01" larger than factory new. A full hundredth. No way they are going through a die. Yes, I used multiple dies; Redding FL, Redding Type S, Redding Shoulder Bump, Forster FL, and Forster Bushing Bump. Not happening.

So the question: Can this be anything other than an extremely loose chamber?

I am going to contact the factory as soon as possible but, that may be impossible with most companies being flat on their butt "due to COVID".

Here is one of the better groups. The factory Hornady AMAX did just as well.
View attachment 205436
First, do a chamber cast. Or get a gunsmith to do a chamber cast. If its over sized (and it is, i'm sure) get a new barrel with a match barrel. Either that, or get Lee or RCBS to make you dies using one of the casings. But keep in mind that if your brass is that far out of spec, your primer pockets are going to loosen pretty quickly. The best fix is to get a new barrel with a match chamber.
 
What am I missing here?
Somebody please correct me if I am wrong but my understanding is
If his chamber is fluted, 30-50% of the case walls are not supported and the brass is fire forming to the fluted chamber.
My thought is if the case is expanding past the chamber diameter in the fluting, it doesn't mean the chamber is oversized. It just means that portion of the case where you can plainly see the flutes is bigger than the part of the case that's supported by the chamber walls.
There is nothing you can do to correct that.
I bought an H&K 91 30+ years ago and at the time I wasn't aware it had a fluted chamber, I knew nothing about the design. But specifically because it has a fluted chamber I never have attempted or never would reload those cases. To me, the brass is compromised from that. I know people reload them but it seems to me that work hardening the brass along the case body like that is not such a good idea.
I may be wrong and maybe I'm not articulating what I'm trying to say just right but at the risk of sounding dumb about it, what will a chamber cast or switching types of sizing lube going to accomplish?? The chamber will still have flutes and I'm convinced that is the whole problem.
Again, I apologize if my questions seem sarcastic in any way but I truly want to be educated. Maybe I'm not seeing something obvious??
 
What am I missing here?
Somebody please correct me if I am wrong but my understanding is
If his chamber is fluted, 30-50% of the case walls are not supported and the brass is fire forming to the fluted chamber.
My thought is if the case is expanding past the chamber diameter in the fluting, it doesn't mean the chamber is oversized. It just means that portion of the case where you can plainly see the flutes is bigger than the part of the case that's supported by the chamber walls.
There is nothing you can do to correct that.
I bought an H&K 91 30+ years ago and at the time I wasn't aware it had a fluted chamber, I knew nothing about the design. But specifically because it has a fluted chamber I never have attempted or never would reload those cases. To me, the brass is compromised from that. I know people reload them but it seems to me that work hardening the brass along the case body like that is not such a good idea.
I may be wrong and maybe I'm not articulating what I'm trying to say just right but at the risk of sounding dumb about it, what will a chamber cast or switching types of sizing lube going to accomplish?? The chamber will still have flutes and I'm convinced that is the whole problem.
Again, I apologize if my questions seem sarcastic in any way but I truly want to be educated. Maybe I'm not seeing something obvious??
Its an AR10 so I don't think the chamber is fluted.
 
Future posters to this thread:
1: Read all comments before posting
2. And stop posting since the OP was written in 2020 because you made me read the entire 188 previous posts.
I was going to post the same thing but figured, what the hell, talking through your hat or out your lower vent seems to be well accepted on the net.👨‍🦯
 
Okay, so a couple of questions:

1. What is "spec"? I just spent some time at www.saami.org looking at drawings. SAAMI list MAX Cartridge and MIN Chamber drawings. There is no MAX Chamber dimensions listed. Also, being that SAAMI spec is voluntary manufacturing recommendations, is anyone really held to SAAMI spec? The fired casings do measure way over MAX Cartridge spec at the base and shoulder of the case but, that is before resizing.

2. How much more information is a chamber casting going to give me over the fired case? We all know that the brass casing retracts in size after firing. Otherwise it would not extract and eject. If SAAMI list no MAX Chamber spec, how can I point the finger at the manufacturer for being "out of spec".

What am I missing here?

Still in the cue and on hold with the manufacturer.
Saami specifications for the chamber are going to be between the SAAMI minimum cartridge size and the SAMMI maximum cartridge size. In other words, cartridge and chamber have the same specifications for maximum and minimum sizes.
 
Curiosity got the best of me.
From the instruction manual:
"WARNING: ONLY USE QUALITY MATCHGRADE FACTORY AMMUNITION. FAILURE TO USE THE CORRECT TYPE OF AMMUNITION MAY CAUSE OPERATION FAILURES, DAMAGE, INJURY, OR PROPERTY DAMAGE. NO STEEL CASED AMMO!"
Along with that the patent describes the chamber design which has helical/spiral grooves up to .001 depth per side that is designed to reduce the drag out forces during extraction, among other things. If you think of it as a shallow rifling, the brass is going to be embossed. The dies available will not be or will have a difficult time overcoming the embossed size of the brass.
Since it was "military" in its intended design, no one is picking up spent brass on the field. It's my estimation, it is scrap brass and incapable/near impossible of being resized for reloads.
And that is probably their angle. New manufactured factory match ammo only.
Edited add owners photo. This brass is embossed.
Happy Toddlers And Tiaras GIF
 
Update:

I returned the rifle to the factory. They shot 3 shot groups (suppressed with their suppressor) until they got a 3 shot group under 1 MOA (barely) and called it good.

My suppressed groups with the AAC MK-13 opened up to about 6 inches at 100 yards and changed the point of impact almost 7 inches. I tried a Q Thunder Chicken and the results were equally as bad. I have never suppressed any weapon and had it suck this bad.

"Accuracy guaranty is only with our proprietary breaks and suppressors" - Larue. Of course, they don't have any.

I also had the little cotter pin that holds the firing pin in the bolt break. It was proprietary. No other manufacture's pin in the planet would fit. It took over 2 months to get a new one from Larue.

Larue refused to take the rifle back and refund my money. After putting it all back to original configuration, I sold it. After all, it did shot good without a suppressor on it but, still trashed the brass.

Never another cent of mine will go to Larue.
 
side issue
dont mean to hijack your thread

monday morning & out of work
so I have a little time on my hands

I been reloading and competing for 15 years

I thought I'd share some of my experiences with my "AR-10's"

I have 2 Armalite AR-10s in 308 both 20"
both are very rough on brass
1 home built Aero Precision AR-10 chambered in 6.5cm 24" also rough on brass
1 DS Arms metric FAL 16" brass is fine

All 3 guns when new would not run right
none of them and very $ frustrating $

they were all "too tight"
meaning mags and springs

the solution I found on the internet was to load the mags full and let them sit for a few weeks
this helped

along the same lines, noodled this out myself
I kept each rifle's return spring locked back for a similar period of time
this was the final piece

the FAL took the most number of breakin rounds
and had one bad factory mag

now I can heat up those barrels really well

I also run new guns wet with oil for breakin
everything wet
every moving part
sloppy wet

is it possible you have a sticky bolt face?
delayed bolt face?
causing overpressure?

compare your AR10 bolt/carrier movement to a AR15
sticky/slick/loose?

good luck
enjoy the journey
AR's are meant to be greased up sloppy wet to run well....especially during breakin period...of several 100 rounds
 
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