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Posted: Wed Mar 09, 2011 1:59 am
by jackssmirkingrevenge
POLAND_SPUD wrote:Wow don't you think it sounds a LOT more menacing in German...?
Everything does :)

Well, breech destroyed, but the cartridge was intact after an 8x mix, I remember DR's warnings when I first considered hybrids *gasp* over 5 years ago and chuckle :D

Now that I have a much greater appreciation of the forces involved I can design accordingly. A thicker and heavier bolt would certainly be a start, I have plenty of 6mm diameter steel rods lifted from printer cartridges which would be ideal. This would in turn reduce forces on the ejector and breech in general.

Posted: Sun Mar 13, 2011 11:02 pm
by JDP12
is there any progress on this at all? I plan to pick up some materials tomorrow... and make a prototype or two.

Posted: Sun Mar 13, 2011 11:15 pm
by jackssmirkingrevenge
I've put it on hold at the moment, I want to look into other materials in terms of cartridge body as you had suggested earlier, as well as some extruded aluminium section to serve as a basis for the action - which is also a technique currently being used in modern firearms such as the M82 or LSR-50.

Posted: Sun Mar 13, 2011 11:24 pm
by POLAND_SPUD
First Egypt and Libya, then the earthquake in Japan... now jsr has announced that he's going to use off the shelf standardised parts

:wink:

Posted: Mon Mar 14, 2011 12:07 am
by jackssmirkingrevenge
POLAND_SPUD wrote:First Egypt and Libya, then the earthquake in Japan... now jsr has announced that he's going to use off the shelf standardised parts
Looking good for 2012 isn't it :D

Don't worry though, it will all be epoxied anyway :P

I've been thinking about moving to bolt action...
[b]the ultimate online Welrod resource[/b] wrote:At an earlier stage, SOE had already experimented with reducing the blast from an ordinary pistol but even when successful in reducing the muzzle blast, the significant noise of the weapons working parts remained. In addition, a conventional weapon fitted with a suppressor became disproportionately big and consequently difficult to conceal on ones person. The decision was therefore made to develop an uncomplicated single-shot pistol based on a rotating breech to be worked manually.

Posted: Mon Mar 14, 2011 8:00 am
by mark.f
I think you should go with bolt-action. There's something so cool about ilovefire's hybrid catridges and their *click*reload*click*reload* sounds in the breech/barrel he whipped up. :D We already know there's plenty of kinetic energy to be had at subsonic velocities...

Posted: Mon Mar 14, 2011 8:30 am
by jackssmirkingrevenge
mark.f wrote:There's something so cool about ilovefire's hybrid catridges and their *click*reload*click*reload* sounds in the breech/barrel he whipped up.
Certainly, added to the benefits of compactness, power and quiet action.

The only bother is:

- fashioning an extractor claw, which really isn't that much of a big deal:

Image

- grooving or adding a rim (I didn't want to say "rimming" :roll: :D) to each cartridge, which is a bit more tricky.

Definitely something I'll be looking into though.

Posted: Mon Mar 14, 2011 8:36 am
by Crna Legija
In the back plug you could put a peace of steel or magnet and have another magnet on the bolt.

Posted: Mon Mar 14, 2011 2:41 pm
by JDP12
JSR- you could do magnet as he suggested.. or just get a piece of pipe that your cartridge body will fit in, and cut a thin slice of it, and glue it on your cartridge.. et viola, rim

Posted: Tue Mar 15, 2011 12:43 am
by jackssmirkingrevenge
-_- wrote:In the back plug you could put a piece of steel or magnet and have another magnet on the bolt.
That could work but a tight breech and magazine would provide a lot of friction which would probably be too much even for strong magnets.
just get a piece of pipe that your cartridge body will fit in, and cut a thin slice of it, and glue it on your cartridge.. et viola, rim
Good suggestion, though you would end up with a "banana clip" - unless of course aside from the ring you also sleeve the main body and leave a de facto groove.

As to my latest single shot suppressed prototype, fail, once again I've been let down by a leaky burst disk. I should give the piston hybrid idea another go.

Posted: Tue Mar 15, 2011 10:34 am
by mark.f
Just a brainfart I had last night.

If a blowback design is implemented, I can think of one simple way to increase performance and reduce noise, although not perfectly.

Extend the barrel about an inch or two inside the cartridge itself when the cartridge is loaded. Example, instead of using a gasket/etc. to seal the cartridge on the barrel, extend the barrel about an inch or two back, and have the cartridge load onto it. The barrel can seal in the cartridge by a simple good fit, an o-ring, or in this case, pressinng against the same tubing used as the detent. Recoil will allow the cartridge to move back the couple of inches or so, and hopefully, with careful design, the length can be adjusted so that the cartridge unseals from the barrel only after the projectile has left the barrel (and your integral suppressor has done its job. :D ). Only downside is a reduction in chamber volume due to the coaxial configuration...

Not much, just a concept drawing below:

Posted: Tue Mar 15, 2011 5:49 pm
by Zeus
In regards to recoil, do you think a hybrid cartridge roughly the outside dimensions of a 12 gauge shell firing a .32/.357/.41 lead projectile would have a reasonable amount of recoil. I'm thinking about 15X, 20X.

With the violence your cartridges extract I'd have some fun anyway.

I liked ilovefire's hybrid rifle, and the Welrod opens up a few possiblities regarding silenced pistols.

I intend to get a bullet mold in either of the listed calibres, they seem to be rather common.

The loading mechanism should be interesting, bolt action would be a little large, I'm thinking a crude falling block currently.

Posted: Wed Mar 16, 2011 12:30 am
by jackssmirkingrevenge
mark.f wrote:If a blowback design is implemented, I can think of one simple way to increase performance and reduce noise, although not perfectly.
Interesting idea, it would definitely cut down on recoil forces because the gasses wouldn't be acting on the full cross sectional area of the cartridge, but this might then have the negative effect of not producing enough force to cycle a blowback action.
Zeus wrote:In regards to recoil, do you think a hybrid cartridge roughly the outside dimensions of a 12 gauge shell firing a .32/.357/.41 lead projectile would have a reasonable amount of recoil. I'm thinking about 15X, 20X.
You mean like this one ;)

Image

Yes, it would work just fine :)

In the meantime I've made a small piston hybrid prototype, to be tested this evening, looks something like this:

Posted: Wed Mar 16, 2011 12:56 am
by JDP12
Looks good... just to confirm, is the ignition sparking against the barrel? Just want to make sure I'm readin the diagram right

Posted: Wed Mar 16, 2011 1:07 am
by jackssmirkingrevenge
JDP12 wrote:just to confirm, is the ignition sparking against the barrel?
That's correct. The piston is the seal from a 5mL syringe (just the rubber) and there is a pinhole (literally) in the syringe tube for equalisation. I also epoxied a short length of silicon tube to the breech end of the barrel to prevent it curring into the piston under pressure.

Edit: curring? I meant cutting. Yes.