Brass issues, post here

[rjacobs]

Well you are missing quite a lot then. Like I said, Lake City brass prepped in the EXACT same manner with the EXACT same projectiles, primers, and powder work without even a single hiccup.

Was your RP brass 5.56 or .223? Although it should really matter I dont think.

[caliplt]

I'm new to 300 BLK, read thru the kaboom thread and agree it's most likely a thick neck pinching the bullet.

As far as that thread goes, I doubt it was thick necks causing to much neck tension. I put a pretty firm crimp on mine that would put WAY more neck tension on a round than a thick neck would, at least I think it would. If a case had a thick neck and was then forced into the chamber it could then put a lot of neck tension on the bullet and cause an over pressure situation, however I would think if that were the case the round would not fully chamber.

But, another iteration of that thread is not what this thread is about.

I am trying to determine if a certain brand of die or barrel or certain case conversion process is producing out of spec brass or if its the actual brass that is being converted. So far there is not enough data to support anything.

You can keep doubting all you want, and I will keep telling you the exact same thing. LC brass works...RP does not. What's your question?

.223 brass

[rjacobs]

You can keep doubting all you want, and I will keep telling you the exact same thing. LC brass works...RP does not. What's your question?

.223 brass

Why did you quote my response to somebody else that had NOTHING to do with anything you and I were talking about?

Ok, so .223 brass didnt work, but the 5.56 brass did. That adds another piece to the puzzle.

[caliplt]

You can keep doubting all you want, and I will keep telling you the exact same thing. LC brass works...RP does not. What's your question?

.223 brass

Why did you quote my response to somebody else that had NOTHING to do with anything you and I were talking about?

Ok, so .223 brass didnt work, but the 5.56 brass did. That adds another piece to the puzzle.

Yeah, I'm really interested to see how it performs post Sinclair "massaging". To be honest, I am just thankful it works. I was about ready to throw the damn thing into the woods.

[Whole Bunches]

To help the original poster, please start here: http://www.saami.org/PubResources/CC_Dr ... ackout.pdf

See the spec for the cartridge neck diameter of .334" and the spec for the chamber at the neck. If the loaded round measures .334" or less in neck diameter, it should chamber fine. .335" it will probably chamber fine. .336" it might need a little force to chamber. Bigger yet, it will normally fail to fully chamber. It has been my experience that the loaded round neck diameter is the critical dimension, assuming the rest of the case was full length resized and trimmed to the max length or less. I own a total of 7 300 BLK uppers and rifles. Once I found the "secret" of the loaded neck diameter max measurement, I could simply measure and know they would chamber fine for me. I WOULD PREFER THAT SOMEONE MADE A CHAMBER GAUGE I COULD DROP THE LOADED ROUND INTO, but alas no one currently makes such a thing that I am aware of. The Wilson gauge is not designed as a chambered case go/no go gauge per their email to me about the subject and inside neck measurements of the gauge.

I'll try and find my post containing the list of .223/5.56 headstamps which have given me chambering problems (with no neck thinning/reaming/turning) and edit this reply with that list. I did not keep thorough records of the thickness of the case wall at the neck, but the problem headstamps did have thicker case neck walls than say LC, RP, WCC, Federal.
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Here's my old post, followed by some case neck measurements in a followup post:


I recently bought 1K of formed mixed brass. About 1/3 of the order won't work. The resulting loaded rounds have too *wide a case neck to chamber (tried in 3 different 300 BLK bbls). This is with loading .308 bullets. Problem headstamps are: ATI (Turkey), PMP (South Africa), CJ (China), NPA (Taiwan), PPU (Yugo), MKE (Turkey), FNB (Belgium), FNM (Port), S&B (Czech), IMG (Guatemala), RORG (Britain), RWS (Germany), and TAA(? Taiwan). You will note that none of them appear to be American in origin (I could be wrong). About half the CJ and PPU will work, but I gave up as you can't tell if they will work until loaded, and then you have the hassle of pulling the bullets from the half that doesn't work. Headstamp 1K has too small a primer flash hole and pulls my decapping pin out. I would need to ream the case necks; I've looked into buying the tools for that, and it just isn't worth it for me. I will never buy formed mixed brass again. I had to do a lot of "mortoring" my AR's to get stuck ammo out until I found I could measure the case neck prior loading the magazine. I even tried full length resizing prior to loading; it made no difference.

*=When the neck diameter of the loaded round exceeded .336, it was hard or impossible to chamber. I just looked up the 300 BLK chamber specs, and it calls for the neck area to be .335".

Edited to add: I don't recall ever having a problem with loaded 300 BLK brass formed from American made .223/5.56 brass cases having too wide a case mouth diameter to fully chamber as long as the case length was within 300 BLK specs. I have sent feedback to the maker using the mixed cases for 300 BLK forming, as they may not be aware of the problems in using mixed (foreign made) brass that appears to be too thick to form and use as-is. I also updated the countries of origin.
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Some measurements:


My dies are Redding. I've been successfully using them for a while now (around 10,000 reloads). Maybe they are worn out? But they work fine with U.S. brass. An an experiment, I just took some sample cases, lubed, full length resized with carbide expander ball in place, wiped lube off and measured. Did not seat a bullet. I realize one of each headstamp is a small sampling, but it showed a trend. Remember, I'm having failures to chamber with PMP and NPA brass (among others) and have tried them in 3 bbls.

PMP
Outside neck diameter: .3384" (larger than SAAMI chamber spec even before seating a bullet)
Inside neck diameter: .3005"
Neck wall thickness: .016"

NPA
.3351" (might or might not chamber as SAAMI spec is .335" + .002")
300"
.016"

Remington factory 300 BLK
.328"
.304"
.011"

LC 03
.3295"
.304"
.011"

WCC 06
.328"
.303"
.0115"

In this very small sample, U.S. brass had thinner case mouth wall thickness and had as sized case neck diameters less than SAAMI chamber specs.

I've been reloading 40+ years, but am open to learning more. I've been merrily loading and shooting the 300 BLK until I got into this foreign made brass. Remember, I'm the guy wearing out several different types of BLK bbls to see how one lasts over others.

Edited to add I did another WCC case and got:

.328
.302
.011

[rjacobs]

Excellent post Whole Bunches.


I wonder about running the cases up in the sizing die, but not running the neck sizer ball through them, as was pointed out in the other thread as thats the last piece that goes back through. So thick necks would cause the expander ball to push the neck of the case out more than it should and then its out of spec.

I wonder if doing this would still allow you to seat a bullet in the case though and if it does, if that case would then be out of spec or if it would stay in spec.

[dead-bird]

Add Amerc to the "too thick" list.

[rjacobs]

Add Amerc to the"too thick" list.

What is the actual head stamp?

can you provide the details I asked for in the first thread as well?

And since you say its "to thick" can you provide the measurements like Whole Bunches did?

[Ben B.]

In my case, I bought 2,000 300 brass made from range brass. About 40% are problems. In my case, if the head stamp is faint, the case walls at the neck measure about .014 to .017. The cases with clear head stamps measure .0105 to .0115. A variety of brass make up the bad cases, including LC. I assume this means that the faint head stamp brass has been reloaded several times before it was cut for 300 brass.

[dead-bird]

Add Amerc to the"too thick" list.

What is the actual head stamp?

can you provide the details I asked for in the first thread as well?

And since you say its "too thick" can you provide the measurements like Whole Bunches did?

I know too thick to chamber isn't an exact measurement but I think it sufficent. When I full length size, I use Redding 300/221 dies. Brass conversion is done by me. I have a mix of barrels in Whisper and Blackout in single shot, bolt gun and AR platforms.

I kept records in the early days of the Whisper. Now, not so much. For me, brass issues are the same for Whisper and Blackout. I had a list of unsutable (too thick) brass but it got so long, it seemed much simpler to stick with domestically produced comercial and military LC brass for conversion.

The Blackout, unlike the Whisper, isn't a wildcat but you face the exact same problems once you decide to use brass that wasn't designed for it.

I only mentioned A-merc as I thought Whole Bunches and I had talked about it, but I didn't see it on his list of problem child brass.