Author Topic: Project Fury 20mm BIGbore. 3100FPE! (Read 86370 times - 2 votes)
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rsterne · « **Reply #340 on:** November 26, 2017, 12:42:09 PM »

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The aluminum muzzle brake is frosted every shot

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we've had even layer of ice on barrels

Those two observations are great evidence that the cooling is significant, especially when you consider the mass of the muzzle brake or barrel that has to be cooled by the mass of the expanding and cooling gas....

The Joule-Thompson coefficient is a different thing than Adiabatic cooling on expansion.... The J-T effect occurs during reversible expansion, not the free expansion that occurs on firing.... The specific heat of Helium is different than air, however, so it may not cool to the same degree as air during a shot.... In any case, interesting observations, we can learn from them....

Bob

MJP · « **Reply #341 on:** July 23, 2018, 08:48:56 AM »

I want to know how overkill one can go with valve and porting, so this should be interesting.
Savage .457 barrel fitted to the Fury frame.

Marko

Rob M · « **Reply #342 on:** July 23, 2018, 10:26:22 AM »

lol, the 457 barrel looks like a pea shooter on there

this will be supersonic

MJP · « **Reply #343 on:** July 23, 2018, 10:44:10 AM »

And that is 815mm long barrel. Still it looks small.

rintafile · « **Reply #344 on:** July 23, 2018, 11:18:53 AM »

Unreal... It sending projectile so freaking fast if everything works like should.. Hope you get Labradar information

MJP · « **Reply #345 on:** July 27, 2018, 04:18:15 PM »

Oh well, range day was not a complete success. Did manage to get some numbers with labradar, but in the hastened packing episode before leaving home to the range and I picked the wrong ammo box from the table.
So had only 292gr bullets to shoot, when I was planning to go from 290 to 620gr
Well the valve worked ok with the slugs we got, got 346 m/s (1135fps)with the 292gr bullets on 300bar. So some 835fpe I think.
Timo had some bullets that were slightly heavier but I dont remember the speed or weight.
Timo can comment on those.
There should be more there I'm sure.
Did shoot couple of groups on max pressure but nothing too special, maybe within 2" or something.

This was a quick test just to see how the valve reacts. And I will visit this thing again with more heavier bullets.

Marko

rsterne · « **Reply #346 on:** July 27, 2018, 04:51:33 PM »

Nice first outing.... I will be particularly interested what velocity you get using bullets in the 450-500 gr. range at 300 bar....

Bob

MJP · « **Reply #347 on:** July 27, 2018, 05:42:18 PM »

Thanks Bob,
You and me both, had a box of sorted bullets from 292, 340, 360, 385, 450, 500, and 620gr if I remember all the weights correct. But just had to pick the wrong one. Already had 290gr box in the bag and took one with weight sorted 292.1-292.3gr box. Had the box lids mixed up, and didn't look inside.

Marko

TPL · « **Reply #348 on:** July 27, 2018, 06:28:29 PM »

Something like 390 gr were the heavier ones I had but they were sized down to .452 as you've should of have .457. I don't remember exact speed but do remember max. KE we calculated. It was 1240 J (914 fpe). So the speed must of been something like 313 m/s (1027 fps) by calculation.

K.O. · « **Reply #349 on:** July 28, 2018, 04:45:34 AM »

Quote from: TPL on July 27, 2018, 06:28:29 PM

Something like 390 gr were the heavier ones I had but they were sized down to .452 as you've should of have .457. I don't remember exact speed but do remember max. KE we calculated. It was 1240 J (914 fpe). So the speed must of been something like 313 m/s (1027 fps) by calculation.

A friend showed me his method with his .45-70 Sharps years ago...

https://www.google.com/search?rlz=1C1GNAM_enUS688US688&ei=chNcW8f9I4fLjwSSkJ6oBg&q=paper+patching+.45-70&oq=paper+patching+.45-70&gs_l=psy-ab.12..0i22i30k1l2.2716830.2740248.0.2749484.29.26.2.0.0.0.308.3710.0j21j2j1.24.0....0...1.1.64.psy-ab..3.26.3711...0j0i67k1j0i131k1.0.CcSZKGZ3bUQ

TPL · « **Reply #350 on:** July 28, 2018, 08:27:03 AM »

In this case paper patching was out of the question because it still is 20 mm upper equipped with .457 barrel just to see what happens. When Marko forgot his "loading aid" home, it looked difficult to load.

Anyway, here is a video of the fight results against some tins of smashed tomato something and one fruit coctail with light weight HP. I bet it was supersonic, but did we even measure?

youtu.be/_X27M0ailUo

MJP · « **Reply #351 on:** July 28, 2018, 09:09:07 AM »

Well it was like 30deg C in the shade and everyone was more than exhausted from the heat.
Very unusual to have so hot wether for so long period here.
I dont have so good tolerance for heat anyway so I'll blame it on that.
Still interesting results on the first tests.

Marko

uncle paulie · « **Reply #352 on:** July 28, 2018, 03:20:49 PM »

Maybe a tad too much power....if you go hunting with that thing there won't be anything left for dinner!

Verrrry Cool!

pv

TPL · « **Reply #353 on:** July 28, 2018, 03:31:17 PM »

Errr.. we actually can't hunt anything here with airguns so there will be no wasted meat.

rintafile · « **Reply #354 on:** July 29, 2018, 12:50:46 AM »

Exept those tincans full of fruitcoctail or tomato

K.O. · « **Reply #355 on:** July 29, 2018, 04:04:36 PM »

I can say that must have been a literal BLAST to have fun with.

MJP · « **Reply #356 on:** July 30, 2018, 12:56:51 AM »

Yeap, it was fun!
Loadin it was a pain without the sleeve I made for smaller projectiles, it was real easy to get the bullet in the transferport.

Marko

E30_S50 · « **Reply #357 on:** July 30, 2018, 10:45:57 PM »

This thing is insane. You should probably begin production and sales.

MJP · « **Reply #358 on:** July 31, 2018, 02:33:51 AM »

Thanks Matt,
Unfortunately I can't do that, need to be certified gunsmith here in Finland to make bigbores for sale.
And that would require four years of education.
So this will be one of its kind.

Marko

MJP · « **Reply #359 on:** October 15, 2018, 05:26:57 PM »

Season ends here in Finland, land of the crazy and thousand lakes.

I don't know if it's just me but the further from "sane" we get the more interesting it gets.
More materials to be ordered and parts to be made, there is more power to be found.

The way I see it, if it can be broken with one caliber it can be done with others also.

Stay tuned

Marko

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Project Fury 20mm BIGbore. 3100FPE!

Author Topic: Project Fury 20mm BIGbore. 3100FPE! (Read 86370 times - 2 votes) )

Author Topic: Project Fury 20mm BIGbore. 3100FPE! (Read 86370 times - 2 votes)
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