The random rantings of an old, 63 years, knifemaker (please don't say "bladesmith") on tools, technology and the world's unfortunate tendency toward overcomplication.
Saturday, January 17, 2009
"Stupid is as Stupid does, Sir" SAFETY BRIEFING
Well, since Assrot and Andy have weighed in expressing concern for my well-being, it is now (finally) incumbent upon me to address the safety issues.
The major of such issues being, so to speak, "did Kurt Saxon blow off his fingers with the FWSG?" ("four winds shotgun", duh).
On a hilarious side note; while obsessively tracking all those bored enough to find themselves here, I found one arrival from an AOL search "did kurt saxon loose his fingers" (sic).
But I digress; I came across the FWSG on this forum. Of course, nothing is said about it other than it's essentially the same as the other slam-fires, just lacking a stock.
And that it's "perfectly safe". So there.
Ah, but perfection is ellusive.
On said post the statement was made that, "Turns out that the SAAMI's Maximum Average Pressure spec for 12ga. is 11,500 PSI."
I'll buy that - except that, it's LUP (lead units of pressure) not PSI they're talking about. These two figures relate to one another but only vaguely.
Watching Paint Dry- an explanation of the CUP and LUP testing procedures:
Chamber pressure is generally measured in CUP or LUP (lead units of pressure), using the crusher method. In short, a hole is drilled into the chamber of a pressure barrel, and a crusher assembly is placed over that hole and sealed. Inside the assembly is a piston which, when a cartridge is fired in the chamber, is forced to move when the chamber pressure bleeds through the hole in the chamber. This force causes the piston to crush a slug of copper (or lead when measuring shotshell pressure) of known hardness and length. Pressure is quantified by measuring the length of the slug after it has been crushed and comparing that with recorded data tables.
ZZZZZZZZ
Anyway, the guy on the Survivalist board linked to this website which I was happy to find. Lots of handy info.
engineeringtoolbox.com
"This one shows that the Bursting Pressure rating for Schedule 40 galvanized steel pipe is 16,142 PSI (at the required 3/4" nominal size).
Based on these figures, it seems that the paliuntod / "Four Winds Shotgun" IS in fact a perfectly safe weapon. And at about $20 in parts at the hardware store, I think it gets my vote for 'Best Inexpensive Shotgun Of All Time'".
That is an impressive figure. Such pipe would certainly be strong enough for use as a barrel. It's just not "...Schedule 40 galvanized)
It's not the pipe you can get at Home Depot.
However, you could probably find it at McMaster-Carr, along with lots of other bitchin' homemade firearm materials.
Never fear, the numbers for the lumberyard flavor of pipe can be found here.
Not as imposing:
3/4" sch 40, wrought iron (mild steel) pipe; Bursting pressure: 8610 PSI.
This is the figure we're talking about here. When the pipe will blow up.
The other figure listed is the operating pressure. 1080 PSI, at 450 degrees F I believe.
Any engineers out there can bust me on this but I'm betting that the operating pressure refers to the limits of the system rather than that of a discreet length of pipe.
Meaning that, the pipe/fitting interface, the weak point, as anyone who's tried to work on old iron plumbing knows, is what's going to give way. Hence the questions regarding the finger status of Kurt and Dexter.
Those two and the maker of this one, maybe from Ireland (?) "The Irish, the race the gods made mad, for their wars are merry and their songs are sad", depend entirely on maintaining the close relationship of the fitting and pipe in spite of that instantaneous, 11500 LUP pulse.
But, in the case of the slam-fire guns, there's another thing to consider: 1" pipe, "the receiver" is also invited to the party.
Our handy table at Engineering Toolbox informs us that extra layer of steel adds another 8090 PSI to the mix.
Furthermore, this is mild-steel were talking about, low-carbon. It will bulge before it bursts and, if such were to happen, the barrel and receiver would never come apart.
That didn't happen. At least it didn't in my extensive computer models.
Who am I kidding? I've been firing my jewel for a month now, put at least a few dozen shells through it. If I'd blown my hand off during that time, I'm sure someone would have told me. Maybe no one did. It would explain my keyboard prpobblemmmas.
Above, Lena (I've named it after my PI sweetie - don't tell Mama)
The barrel has been shortened to a legal 18 1/2" - easier to poke out the shell in the event it doesn't want out.
I added an extra (paranoid) layer of protection in the form of a section of 1, 1/4" pipe over the chamber, which gets me up around 24000 PSI... theoretically. Help me, Assrot.
The barrel is blackened with burnt-on beeswax, the receiver is painted OD (tres tactical).
Stock is ebonized black walnut.
I added the beverage container to give a sense of scale - and to illustrate one of my principles of "gun control": Never fire guns if you're too drunk.
My other principle is thus: Never buy a gun on credit. Control yourself.
Anyway, she's gorgeous.
I know it. Don't embarrass me by dwelling on that.
Top pic: The real Lena.
On the right, in pink.
I had it goin' on. Fuck yeah...
While I can't say much for your choice in beer, I have to admit that is a darn nice looking shooting iron you made there.
ReplyDeleteI'd say it's fairly safe as long as you don't go trying any 3-1/2" magnum Turkey loads in it.
You should take it to your local range and try a round of trap with it. I'm assuming the bore is open cylinder so you'd have to catch the clays as soon as they come out of the house else you won't have the range for them.
I'd bet you'd get some decent offers to buy that beast.
Personally, I really like it. I'm impressed.
Joe
Thank ye, Joe.
ReplyDeleteRe the PBR; just simply quantity vs quality.
In a perfect world, I'd drink Moosehead but at around 8 skins a six pack that can't happen often, being that I have an addiction to maintain on a limited budget.
A case of Guiness Extra Stout would make a nice gift though.
Pretty cool Dan!
ReplyDeleteShould scare the CRAP out of EPD:-)
Now you should try the old Teddie Roosevelt trick. in African Game trails he mentioned not having slugs and so he poured some parrafin over the shot in the shell and improvised a slug..hey I mean as long as you're improvising an all...
Good job, keep up the good work!