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Posted: Tue Mar 02, 2010 5:31 pm
by SEAKING9006
Well, not PURE blowback. Most of the force behind ejection comes from the ejector pin, usually in the bolt face itself, pushing on the rear of the cartridge which is still held by the extractor claw, creating an effective lever, allowing compairitively light springs to throw out fairly large cartridges.

At least he wont have to spend much time shagging brass... :lol:

Posted: Thu Mar 11, 2010 5:08 am
by zomgwtfbbq
Could you post a video please?

Posted: Mon Mar 15, 2010 6:32 pm
by irisher
UPDATE: I just tried a full blown 15x shot. It fired successfully but, due to the size of the cartridge, the burst disk was launched out the muzzle. Along with the burst disk an oring was shot out as well. I am now thinking about abandoning this project.

Posted: Mon Mar 15, 2010 6:43 pm
by Gun Freak
YOU CAN'T STOP NOW! :D But seriously. Never give up.

Posted: Mon Mar 15, 2010 10:03 pm
by irisher
More Fail :( I was examining the cartridge when I spotted a serious issue. The burst disk holder on the male side had broken loose. I assume due to heat/pressure swell in the metal. I prodded it some more and the entire thing came out.

Posted: Tue Mar 16, 2010 1:07 am
by jackssmirkingrevenge
Shame, it was looking great.

Posted: Tue Mar 16, 2010 4:08 am
by iknowmy3tables
15x is quite a lot I wouldn't be surprised if you had some problems, you should at least share more details with us I'm still not sure how the burst disks go on this thing

Posted: Tue Mar 16, 2010 12:09 pm
by psycix
Step down the mix number, fix the issues, and try again.

Posted: Tue Mar 16, 2010 1:30 pm
by POLAND_SPUD
ohh damn.... somehow I missed this thread... I thought that's one of JSR's threads on hybrid cartages :)

while I am not a big fan of cartridges (no need to copy the way firearms work to build something that in essence is completely different from firearms) I must say I am impressed with quality of your work...
seriously, just for this reason and to be make sure whether it's a good idea or not you shouldn't stop now.. try again.. and if that fails try again a couple more times

Posted: Tue Mar 16, 2010 1:54 pm
by Mr.Sandman
POLAND_SPUD wrote:ohh damn.... somehow I missed this thread... I thought that's one of JSR's threads on hybrid cartages :)

while I am not a big fan of cartridges (no need to copy the way firearms work to build something that in essence is completely different from firearms)
Surley you would change your opinion if one were to make a semi automatic shell ejecting system such as deus ex machina? My only gripe with hybrid cartridges is the fact that they require some sort of shell ejecting system to be used effectively vs a standard hybrid.

Posted: Tue Mar 16, 2010 2:14 pm
by POLAND_SPUD
sure it would be cool... but you can achieve the same effect without cartridges...
get one large propane tank instead of X number of smaller tanks (cartridges containing mix), some valves for automated mixing and a loading mechanism (note that it has to load bullets only)

If you take all of that into consideration you'll see that you can get more shots, more power and a lower mass without cartridges...

that's something you can't do with a solid propellants used on firearms... and that's why cartridges make sense on firearms but not so much on pneuamtics and combustions

BTW the military is researching into using flamable gases and liquids for propeling ammo instead of traditional solid propelants... I don't think they are going to switch right away as it would take a lot of $$

(the same reason why 5.56mm calibre is still in use - sometimes it's cheaper to stick to what you've already have)

Posted: Tue Mar 16, 2010 2:26 pm
by Mr.Sandman
POLAND_SPUD wrote: (the same reason why 5.56mm calibre is still in use - sometimes it's cheaper to stick to what you've already have)
That and the fact that its a lot more accurate at longer distances opposed to the 7.62 :D But whose counting?

But unlike the traditional hybrid of which you have desribed, the cartridge design allows increased durability because the same chamber isnt subjected to rapid shots until its reloaded. And in the case that a cartridge is broken, it is easily replaced by another cartridge.

Posted: Tue Mar 16, 2010 2:53 pm
by POLAND_SPUD
IDK, it seems that the US army switched from 7.62 to 5.56 just becasue of lower recoil & lower mass... AFAIK 7.62mm is actually more accurate
But unlike the traditional hybrid of which you have desribed, the cartridge design allows increased durability because the same chamber isn't subjected to rapid shots until its reloaded.
I don't think that is a big problem.. sure overheating might be a problem, but it's not something that can't be addressed

anyway, let's assume you want to test that... so you build a traditional hybrid and you fire 30 shots with it... sure it might be a bit hot after that..

but if you wanted to compare that to a hybrid that uses cartirdges... lol you'd need 30 cartridges... you've got to fill them first, load them (imagine a magazine that can hold 30 cartridges)... etc.
see my point? it gets pretty annoying if you want to fire more than 6 shots or so
And in the case that a cartridge is broken, it is easily replaced by another cartridge
heh similarly you can replace the chamber

Posted: Tue Mar 16, 2010 3:08 pm
by Mr.Sandman
POLAND_SPUD wrote: but if you wanted to compare that to a hybrid that uses cartirdges... lol you'd need 30 cartridges... you've got to fill them first, load them (imagine a magazine that can hold 30 cartridges)... etc.
see my point? it gets pretty annoying if you want to fire more than 6 shots or so
And in the case that a cartridge is broken, it is easily replaced by another cartridge
heh similarly you can replace the chamber
I was actually referring to a bolt action design such a BACH but yes I see that would be a problem, I just think that when going for ergonomics, cartridge design is much more efficient and pleasing. But then again we are all entitled to our own opinions.

Posted: Tue Mar 16, 2010 3:55 pm
by irisher
I think I am going to try get one more shot and get a video of it. I probably will shelf it after that if it continues to blow itself up. I would be nice to have the first semi-auto shell ejecting hybrid cartridge gun.