Hornady brass without flash holes

[FrankenMauser]

Interesting.
I've seen claims for years and years that the larger flash hole will:
A) Increase pressure (presumably and sometimes directly stated, by igniting more of the powder charge and causing faster overall burn).
And,
B) Pierce primers by allowing gasses to flow more quickly to the primer and cause them to see abnormally high pressure. (I don't buy this one. It is Fuddlore to me. At even a low 13k+ psi 'shotgun' or .45 Auto pressure level, a 0.020" flash hole isn't going to restrict flow enough to make a difference - let alone a normal flash hole.)


Unrelated:
This jogged my memory for forgotten projects and made me want to resume experimenting with forward ignition. (Internal tube leading to front of powder charge, from normal primer location.) Previous experiments were years ago, when I had limited tools, materials were harder to find, and I wasn't as willing to color outside the box.

[Unclenick]

I just reread the study I linked to in post 13, and he did find a 1-4% variation in pressure in the two rifle cartridges (223 and 308) he tested. The SD of SAAMI MAP for rifles which is the basis of the stats for their system, is 4%, and the SAAMI MEV (maximum extreme variation) lets individual rounds within a sample go to a theoretical +18% (high but well below proof level). So I will amend what I said in post 25 to say shooters without pressure measuring gear saw no apparent difference in pressure that I am aware of, and the difference of up to 4% will not cause overt overpressure signs if you are loading within the normal data range. However, you can eliminate even that 4% difference by reducing powder charges by about 2%.

I noted on the re-read that the powder used in the paper is WC749, which is a spherical propellant from the St. Marks, Florida plant that GD owns. 748 is available in canister grade in the Winchester brand, but 749 is not. And while 749 is probably close to 748, I don't have any independent information on that, so it remains to be confirmed. Being harder to ignite, the older St. Marks spherical formulations may be more affected by flash hole size than some other powders are. In past experiments I did with flash hole deburring and uniforming, a spherical propellant (2520) was affected measurably by flash hole modification while single-base stick powder didn't seem to change behavior at all. So I don't know how universal that 1-4% effect may or may not be.

[Aguila Blanca]

Originally Posted by Unclenick

No pressure change that I am aware of. Back when Winchester started loading large pistol size lead-free primers in 45 Auto with the NT (Non-Toxic) head stamp, to prevent the higher brissance DDNT sensitizer from creating so much pressure inside the primer cup pocket that it would mushroom the cup, they used roughly 1/8" wide flash holes. Lots of folks reloaded those cases with conventional primers with lead styphnate sensitizer and reported no difference in performance using their usual loads.

Every Winchester 45 ACP case I have ever seen with the NT headstamp has had a small pistol primer pocket. Those who collect range brass for reloading know to sort Winchester NT brass and set it aside, either to be sold or traded off, or to be loaded separately because they use small pistol primers.

IIRC, nobody seems to change their load recipe when changing from "standard" .45 ACP to the NT brass with the small primers, but the people I know who reload are IDPA/USPSA shooters, not bullseye shooters.

[Unclenick]

The Winchester Winclean 45 Auto NT cases had large primer pockets when they first came out. I think that lasted only about a year or two at the most. By the end of 2004, they switched to small primer pockets. They were also getting the NT loads manufactured by S&B in Czechoslovakia at that point, so perhaps it was a fit for what S&B was making. I don't know.

[603Country]

Hornady brass isn’t a brand I use by choice, but when I acquired a 6.5 Grendel, I only had a small amount of factory ammo and no new brass. So, I paid way too much for some Hornady factory loads of 123 gr SSTs, with the intent of reloading the brass, hoping for 5 or more reloads. That made my overspend for the ammo justifiable (to me). Well, I reloaded the brass (50 rounds) one time, and when fired, 49 of the 50 cases split at the neck or the whole neck shattered. Disappointing. The next 50 cases I ‘emptied’, I annealed them but have not reloaded them yet. No more Hornady for me.

[tangolima]

For 6.5 grendel, I would convert from 7.62x39 if I'm out of options. I was about to do that then I found a good deal on a rifle with plenty of brass, Hornady it happened to be.

Well, I drilled the brass to 2.2mm. I think it did increase the pressure some. Downloading 5% is about right. It is an ar-10 in .243 win. It shoots well. Less than 1" at 100yd no problem. The replacement brass from Hornady have arrived. For safety I'm put the new brass away till I use up the drilled brass. It probably will take years the way I shoot.

So far I like .243 win. Still too early to tell, but it has the potential to out do 6.5 creedmoor.

-TL

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[Nathan]

B) Pierce primers by allowing gasses to flow more quickly to the primer and cause them to see abnormally high pressure. (I don't buy this one. It is Fuddlore to me. At even a low 13k+ psi 'shotgun' or .45 Auto pressure level, a 0.020" flash hole isn't going to restrict flow enough to make a difference - let alone a normal flash hole.)

I would suggest you try cutting a big ole hole in a 65000 psi round and give it a shot! I’m not being serious.

[Unclenick]

I don't expect it matters. The primers back out, then are reseated when the head moves back against the breech face. That happens at low pressure in a lot of handgun rounds, for which the whole case backs up, and it happens at somewhere around 30,000 psi for bottleneck rifle cases, IIRC. Once it has occurred, the seal is established, and the primer is surrounded by the primer pocket. I don't think there is any pressure difference in what the primer sees after that. If there were, you'd see signs of gas cutting in the flash holes from the higher-pressure side gas jetting in through it to pressurize the primer pocket. The way to be sure is to look for greater primer flattening as you work up the large flash hole loads.

[RC20]

LOL, quality control on brass?

I have gotten Lapua dented cases and when I checked the primer hole size on the 6.5 x 47, they were all over the map.

I hope no one thinks anyone eyeballs brass (nor primers though I know claims are made on CCI primers being eyeballed for the BR type)

Your quality control is in the accuracy of the process, ie they ensure the mix is the same, the treatment is uniform but no one is going to know with hundreds if not thousands of cases that the hole punch broke off, quit working or the drill bit was gone.

The important aspect is it does not blow up in your face, the rest is gravy.

[mehavey]

Your quality control is in the accuracy of the process, ...

It's called "qualifying the line" in manufacturing. And as long as the (original)
intent of TQM-statistical-process control is truly implemented, works well.

(The Japanese ate our lunch with Edwards Demming/TQM. Believe it.)

[stagpanther]

I was trained in TQM to get my MBA (paid for in part by the oil industry)--works great until there is a disruption in the distribution/transportation system; as we have painfully found it. Went through the whole "indoctrination" thing and everyone was enamored with mission statements and "we're all in this together and each of us is essential to the organization." Good old American capitalism dispelled that bunk after a decade or so.

[mehavey]

enamored with mission statements and "we're all in this
together and each of us is essential to the organization."

That not Demming's TQM. That's the on-its-head disaster dreamed up by the management zealots who didn't have a clue -- but liked the name.

True TQM really is statistical control of a truly repeatable process and steadily fixing/improving outliers as they reveal themselves.

At the end of our 4 days w/ Demming -- One-on-One -- we asked him what he throught of the [USAF] TQM program.

He was blunt: "That's not TQM"

.... WILD applause from the audience of Systems Command officers & senior NCOs.



When the uproar died down, some brave soul asked, "Dr Demming... what are your most useful rules for managers....?"

Came the immediate reply:
- Listen to your people actually doing the work on the [manufacturing] floor
- Don't do anything stupid.


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[tangolima]

I tried 2 different powders, one fast and one slow, with my brass with 2.2mm drilled flash hole. I'm quite certain the pressure runs high, higher MV compared to published data and early on set of pressure signs. I need to drop charge by 5% or so to feel safe. With reduced charges it seems to group quite well though.

I think it is fair to assume published data becomes invalid with enlarged flash holes, and I want to be even more conservative when working the load.

-TL

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[Unclenick]

Would you mind saying which powders they were? I am curious whether there is a correlation to stick or spherical grain forms. If you have any of the blanks left, try a couple of the small flash holes to see if the reverse holds true.

[tangolima]

Faster powder IMR8208XBR, extruded.
Slower powder Ramshot Hunter, ball.

I will drill a couple of 2mm for the next trip to the range.

-TL

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[Unclenick]

2 mm (0.079") will be the standard size. The paper included holes down to 1.2 mm (0.047"), but a lot of the small flash holes I've run into are about 1.5 mm (0.059") or 1.6 mm (0.063"). Be fun to see a same-gun, same-powders comparison across the range. If the small ones don't pan out for you, they can always be drilled out to a larger size afterward.

[tangolima]

Good idea. I will do 1.8mm, 2.0mm, and 2.2mm. A couple of rounds each.

-TL

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