Fillers

[BruceB]

May I respectfully suggest that y'all go back to the thread and read the description/discussion?

Go to "search", and type in the word "karen". The thread is located second from the top of the second page.

Ignition was not a problem. The bolt handle was MOST DEFINITELY all the way down...I was the guy who had to put a four-foot pipe on it to get it open. The pressure was extreme, as you might expect with the bullet lodged in the barrel.

[barrabruce]

303 guy about the .22 ringing.
Iv'e seen a couple of those too. mostly in the same locations as you mentioned.
just in front of the chamber a few inches and about 3/4 of the way up the barrell.

From what I can deduce...just "shade tree tinkering".....

I have "once" had a round that logged in the barrell. About 3/4 of the way up.
It was from an 'old packet of shells that had been sitting around for donkeys years and I think the packet was drenched in gun oil and muck.Probably been rained on an all that too!!

Bad cartridge.
Then a second round through will surely do it.

Awhhh it din't go off...crank another in an try it.

A dud round does sound ..well soundless if there is no gas eminating from the barrell.

[softpoint]

I've wondered about primers being the culprit in some blowups ever since I read Ackley's books many years ago. The infamous "Hangfire?" I don't recall ever having a hangfire. I've talked to one person about 25 years ago who claimed he had one with a freshly loaded cartridge in a .460 Weatherby. A marginal primer could have a problem igniting the 120 grains or so of powder in the old MKV?
His rifle was unharmed, he said, but it is very uncomfortable to have a .460 go off when you have started to take it down off your shoulder,in his words.

[303Guy]

The bolt handle was MOST DEFINITELY all the way down...

Yes it would have been. But that doesn't mean it was all the way down when the trigger was let off. What happens - and this does not imply that it happened in your instance - is that if the bolt is not all the way down, the cocking piece strikes the cocking cam which closes the bolt fully but leaves enough energy in the firing pin to set off the primer. It sometimes shows up as an unusually shallow indent in the primer. It was just a 'maybe/could be/what do you think' type thought or idea. By the way, I know about that particular phenomenon because I am prone to it! (With one of my rifle's anyway - it may just be that particular rifle! Most often it does not go off at all when that happens). But it makes wonder about the possibility in your case. If - and that's a big if - that happened, then ignition would have been the problem. But I stress - that is only a wild speculation on my part!

The infamous "Hangfire?" I don't recall ever having a hangfire.

Well, I've had one! The damn thing went off after had lowered the gun (shotgun) but not removed it from my shoulder. Old ammo!

[rickster]

Has anyone here used pressure tracing equipment to assess the effects of fillers?

[longbow]

Look here for the 6.5 Swede high velocity tests using fillers:

http://castboolits.gunloads.com/showthread.php?t=72897

[405]

This thread is coverin' it all.
I don't see how low density filler like < 1 gr of loose dacron used in front of relatively fast powder has or could have much to do with chamber or barrel rings. However, given the wide variety of odd components that are concocted by shade tree ballisticians... never say never

No more than a couple of years ago an acquaintance told me with absolute certainty that he doesn't use dacron filler because it "will leave a bunch of melted plastic in the bore". No doubt, he heard it from a reliable source who heard it from a reliable source who heard it somewhere?

SEEs are nearly impossible to prove, demo on purpose or disprove. That's why anyone who says they can prove that it doesn't happen by loading some undercharge of slow powder then firing it without consequence proves nothing!

There have been enough instances of undercharge - slow powder blow-ups that it seems almost certain these types of SEEs do happen.

In certain applications/loads it's interesting to note the print-outs of raw pressure trace data. Everytime I see one that does show the multiple pressure spike events it gives me the willies!!! I pay very close attention to those and try to avoid similar load specs.

I don't know how many dogknoted 22 rf barrels I've seen. It must be pretty common. The little 22s have been around for a long time. Over the years much of the 22rf ammo has had a bad reputation for being unreliable. Easy to re-create the events. Load up the ole 22 with who knows what ammo. Fire, fire, no fire (must of not fed another round), fire... ring! What's also interesting is it is not unknown that 22s have been taken to gunsmiths for repair that have multiple 22 slugs still in the barrel

[beemer]

I have also seen a lot of ringed 22 barrels. I think some of it is caused buy kids leaving too much oil in the barrel after cleaning. The one that came to mind was one that put oil in his BB gun to make it smoke. When he went a 22 he did the same thing and guess what happened.

Dave

[303Guy]

caused buy kids leaving too much oil in the barrel after cleaning.

I used to oil my air gun, fire it, insert a pellet into the muzzle a bit, load a pellet and fire. That would cause diesel ignition of the remaining oil fumes and produce a cool 'crack'!

On case dents - I seem to be able to produce them at will. Trapped gas expanding? Or is it shock waves? Take a look at this one.



Only the annealed case mouth collapsed but what a spectacular collapse! No way was this 'trapped gas'. More like a shock wave moving rearward, catching the unsealed mouth (low pressure load) and doing tricks to it! This was fast powder (shotgun). Filler was used. The filler was found attached to the boolit base in the sand trap.

By the way, I have seen a broken P-14 bolt locking lug. This is a strong action so what could have broken that lug off? Shock waves?

[Bulltipper]

I came across squib loading in my "Complete Handloading Guide" by Phillip B Sharpe and it really sparked my interest. I wanted to be able to light load my 30-06 or 308 for varmint hunting with lead boolits and not have to wear ear protection if i didn't absolutly need to. I found this thread a couple weeks ago and read it completely and found a lot of good information from all of you. I approached this experiment cautiously as I greatly feared Ringing the Chamber! My goal was a 1100 FPS 175 grain boolit. Yesterday I finally got my .309 size lube die that was the last piece of tooling needed. I loaded 7 grains of 700x shotgun powder (my smoke of choice) added my filler of dacron (about the size of a cotton ball) and put on my face shield, safety glasses, level 4 body armor and kevlar helmet and went down to the range in front of my house. (i live in rural Oregon) My first shot registered 1092 on the chrony, was really quiet and had light recoil. I opened the bolt and the bore was spotless shiny and clear. The poly fill lay on the ground about 15' or 20' in front of me singed but not burned or melted (almost seemed like it would clean the bore really nice!) Following shots were a little slower but always cleared the barrel and I had no mishaps. I finally wound up the load to 7.3 grains of 700x and I am at about 1125 to 1150 fps. Eye protection is as always mandatory, but hearing protection is optional which makes it great for coyote shooting, rock squirell, and general plinking. I am putting just enough poly fill in the case to keep the powder charge in the back and not allow it to move around. I am also storing these cartriges upright ONLY. At this point I am pulling the bolt after every shot to check the barrel (Ruger m-77) Can any of you see anything hazardous here that I may be overlooking? I realize I am completely out on the "experimental" limb here but I am really having a good time with this. Thank you all for your previous comments and information on this thread, it has been very helpful!
kevin

[barrabruce]

You may wanna read this. I aint not expert but here it is.
http://castboolits.gunloads.com/showthread.php?t=56342

AS to exploding guns with reduced carges.

One explaination Iv'e read that satifies my mind is.
Goes somthing like this..if I can find it I'll post it here.


SSE detonation is caused by a bad primer ignition or primer.

The primer when struck smoulders and not burns.
The heat or slow fizzling some how.
Changes the powder charge to an expanded a explosive gas.
When ignition occurs it is this now highly volitile gas that does the damage.

Remembering than gun powder is a controlled burning substance it sounds like a good explainatioin to me and why it maybe hard to duplicate without fudging primers and I'm gunna be extra nice to my primer now.

Barra

[303Guy]

SEE detonation is caused by a bad primer ignition or primer.

The primer when struck smoulders and not burns.
The heat or slow fizzling some how.
Changes the powder charge to an expanded a explosive gas.
When ignition occurs it is this now highly volitile gas that does the damage.

I have come to suspect this too. Have a look at this primer as it came out the packet.



This does not mean that defective primers are THE cause but possibly A cause. What stops slow powder in a large partly empty case from 'smoldering' before finally 'detonating' with a perfectly good primer - or maybe an 'in spec' but at the lower end, i.e. weak primer? Slow powders have a 'heavy' retardent coating, right? In a large case whith a low load density, the powder may respond to being 'blown away' by the primer flash in an unpredictable manner.