My Reloading Adventures/misadventures

Eh, aloha bra! You must be shooting at Koko Head rifle range. I’ve never been, but I recognized the silhouette of Koko Head from your June 17 blog.

I took my family to Hanauma Bay in June and we could hear the range activity from the upper parking lot/bay lookout.
 
Aloha,
Yes, Kokohead is awesome. They have a peculiar 5-round rule in the magazines but allow steel targets. Thanks for visiting.
 
Can't say I've ever seen a .223 case with dents like that. Have you gotten any more feedback on that one off your 9/2018 post?
 
He didn't state clearly that he knew the case was his; just that it was in the brass he was sorting. But the diagnosis is correct: unburned powder in the chamber. That's a good sign the powder is too slow for the bullet weight and not burning consistently, as it likely spilled out of a case while it was extracted. Using powders that are too slow can lead to ringing the barrel, so if it were my case I'd be looking at something faster. Maybe Reloader 10X or Benchmark or H322. I've used Varget with 77-grain SMK's without issue, but never tried it with anything lighter in 223.
 
Thanks for the info. The Varget has been crazy accurate for me with the 62gr along with CFE223. I'll watch out to see if I get more of these poppers (for lack of a better term of the bullet leaving powder behind in the barrel).
 
The pressure issue that causes ringing doesn't necessarily cause inaccuracy. It's an odd effect where the slow burn of the powder lets a too-light bullet scoot forward faster than the powder can make gas to keep up initially, but as the burn progresses it catches up, shoving a lot of gas mass down the bore where it rear-ends the bullet faster than it can be further accelerated. The excess pressure that results is momentary and tries to bulge the barrel outward. This results in a traveling wave from the pressure sight that goes back down the barrel. A standard pressure transducer or even a copper crusher won't detect it because the wave moves them, too. But a strain gauge sees the metal expanded by the traveling wave. The Pressure Trace instrument can see them, therefore.

Scroll down that page and look at the 7 mm STW and the .223 load shown and the nasty apparent pressure (actually the wave stretching the steel) that you see. A wave as big as the first of those two plots show came from a very high-pressure event down the bore a bit. Texas Gunsmith Charlie Sisk has actually blown the muzzles off 338's with a load that exhibited an extreme secondary hump like that. It takes him about 10 rounds, but they go.
 
Would be interesting to see what pressure this produces. Haven't seen any pressure signs so far. Fortunately, it's a bull barrel so might help. Nosler says the 23.5gr is most accurate but doesn't list pressures. Hodgdon data does.

The ringing theory links are interesting. Another confounding factor is the difference between a boat tail and flat base bullets.
https://www.youtube.com/watch?v=ZDUL_1vrABI
 

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I don't think the slow motion video is so mysterious. The main difference appeared to me to be the amount of bypass gas that got around the bullet before it got to the throat. He may have had the boattail seated with more bullet jump and perhaps with the help of the boattail shape itself, got more bypass gas preceding the bullet. If he developed a load for each that had the bullet jamming the throat that bypass gas would go away.

Note that I had to remove two of your images as they copy copyrighted materials. See the board policy on posting copyrighted materials. You can link people to such data on its own site or write the relevant data for single loads as text if the quantity is not so great as to challenge fair use protection.
 
I usually seat to magazine length in the ARs. I don't remember if I ever did measure the headspace in the ARs. Time to break out the Dremel.

The 5.56 is considered a varmint barrel and seems to like the varmint style bullets (no boat tail). The AK and Mosin bullets all seem to lack BT also. Of course, the 6.5 CM rifle all have the BT.

I don't recall what the images were.

My recent happenings...

https://ronsreloading.wordpress.com/.../24/october-24-2018/
 
excellent grouping with the Noslers and that is first AK47 I have ever seen that I would like to have sitting in my gun safe
 
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