Community Project #1 - Handheld, High Mix, Hybrid

[jackssmirkingrevenge]

Personally, I wouldn't make this launcher any less than about 15 kilos total weight, and even then the recoil will be very serious. (Although a muzzle brake might allow you to cut that slightly).

A hefty launcher will certainly help absorb the recoil, and how about throwing in a NTW-20 style hydraulic damper where the action recoils in the stock?



If I'm not mistaken the TX200SR operates using a similar system, no buffer but the action recoils along a rail in the stock.

[Hubb]

Seeing as how a round must be loaded, the chamber purged then fuel and air added, then the whole getup fired, cartridges may be a good idea to achieve the rate of fire.

BUT, as Ragnarok and JSR pointed out, one round every 20 seconds is not overkill. Actually, most well built pneumatics here can usually produce a rate of fire every 10 or 15 seconds if the shooter were to try.

In short, I think cartridges are a good idea, but they may be a little overkill for this project. Besides, for us to achieve the "5 ounce projectile traveling at 1600fps," that would be one massive cartridge per shot.

Now, if cartridges are what is going to be built, I think we should go beyond the stated goal and push for what a cartridge is really capable of. With a well made (and plenty of) cartridge, we could push this rate of fire from "one round every 20 seconds" to "20 rounds every one second" if we really wanted to.

[jeepkahn]

10x really isn't that much pressure(132.3psi according to Rag), you could actually setup the compression chamber so that it uses a smaller bore and multiple "v.,pumps"(you could fire at say 2.5x, 5x, 7.5x, or 10x)....

I thought that one of the reasons for community project was so that different members could contribute different ideas for different parts of the gun, It seems to me that all the individuals are trying to design the whole thing(quite an inneffecient use of ideas, imho)...

people with experience in fueling can concentrate on fueling methods, people with experience in pneumatics can concentrate on the pressurization, people who have experience with loading mechanisms can concetrate on those, etc....

just my .02$

For JSR we can use spent shell casings as ammo, one of my favorite plinking projectiles for my small bore stuff... What's the OD of a .50bmg case, not the necked down portion? Wiki'd it 22.4mm or .804" a respectable sized round... especially at speeds capable by a 10x hybrid...

[Hubb]

Actually, jeep, there has been no mention of the entire design. All that has been mentioned so far is the chamber portion, and that is only turned into a discussion of cartridges.

We could designate who needs to design what, but I personally think it is better to have anyone put in their input into which portion they feel should be upgraded or worked on. As the project continues (say we decide to make a cartridge hybrid) then there will be another discussion on the remaining portions, such as loading the cartridges, barrel designs, etc.

As far as cartridge designs go, I think using a shell casing is a wonderful idea. Makes the whole thing a lot easier to begin with. And .50BMG cartridges aren't too small to begin with either. Now, if only we had a way to collect a bunch of these cartridges.....

[john bunsenburner]

How about we have a sperate chamber design, when the trigger is pulled the two main chambers are blocked of and the secondary chambers become on firing camber, then we can have some kind of ignition. I have something worked out all the way that just doesn't account for venting, which is important...However you will have to wait to see the Idea as i want to see if it works with pneumatics before posting it. So it may be another month.

Personally I would like thsi goign semi auto, and to have a very fast rate of fire. but that is just me.

[Hubb]

How about we have a sperate chamber design, when the trigger is pulled the two main chambers are blcoked of and the secondary chambers become on firing camber, then we can have some kind of ignition.

That sort of reminds me of a Gen3 hybrid.

[jeepkahn]

I was actually talking about shooting the casings, not making cartridges out of them... But hey, if you can make precharged cartridges with them, go fo it...

[john bunsenburner]

It would be fun to mod used bullet casings into functional catridges...

[jackssmirkingrevenge]

I thought that one of the reasons for community project was so that different members could contribute different ideas for different parts of the gun, It seems to me that all the individuals are trying to design the whole thing(quite an inefficient use of ideas, imho)...

That assumes that there already is a given set of parts if design tasks are to be distributed. If everyone agreed on a car then you can split up body, engine, wheels, transmission etc - but in this case all we know is that we're going from A to B, we don't know if it will be in a car, bicycle, hovercraft, skateboard, itetc.

As to using 50BMG carts, I was envisioning something bigger in terms of calibre to achieve the required high performance (and worthy of a recoil mechanism ) - something analogous to this chinese monster

[jeepkahn]

Any Ideas on the bore size of the barrel??? in relation to chamber diameter, and chamber length???

Will a cartridge hold enough volume to get decent performance even with 10x if it's on a large bore launcher???

Isn't it worth mentioning that while we're trying to emulate powderfired munitions, the military is spending bux trying to do away with them, centrifuge weapons, railguns, etc...

besides, aren't powder weapons just pneumatics that use powder to create pressure, merely using powder as a form of condensed storage... much like using dry ice bombs inside a launcher chamber...

I know, it'ss all semantics anyway...

[Pookydarts]

As to using 50BMG carts, I was envisioning something bigger in terms of calibre to achieve the required high performance (and worthy of a recoil mechanism ) - something analogous to this chinese monster

I love the way you HAVE to fire it 'ghetto style' even when it's up the right way!

Edit: 50BMG shells would need to be in a 50BMG chamber before I'D want to have my face near them at 10x.

Do you guys in the states have 10 bore (gauge) rifled slug guns? That could get the recoil up above what's possible in .50 cal, not to mention making whatever we come up with a serious proposition for hitting rogue two by fours at 100 yards!

[jackssmirkingrevenge]

Any Ideas on the bore size of the barrel??? in relation to chamber diameter, and chamber length???

Will a cartridge hold enough volume to get decent performance even with 10x if it's on a large bore launcher???

I believe these specs were up for grabs, I would say at least 0.75" calibre. If the cartridge is say 1.5" diameter, a 6" cartridge will give a 1:1 ratio with a 24" barrel.

Isn't it worth mentioning that while we're trying to emulate powderfired munitions, the military is spending bux trying to do away with them, centrifuge weapons, railguns, etc...

We're chasing eachother's tails!

It's not only about giving a "real feel" that I'm so enthusiastic about cartridges though, I think they're a practical alternative to a complex fuelling and feed system, assuming of course the intended operation would be akin to a grenade launcher as opposed to a machine gun.

I love the way you HAVE to fire it 'ghetto style' even when it's up the right way!

[jeepkahn]

I think they're a practical alternative to a complex fuelling and feed system,

Not trying to dissuade cartridges, but if you go cart style, how much time will have to be dedicated to charging/loading shells per round fired...

Yes, the fueling may be more complex, but end result would be time invested per shot would be much lower than with cartridges...

[jackssmirkingrevenge]

Not trying to dissuade cartridges, but if you go cart style, how much time will have to be dedicated to charging/loading shells per round fired...

Yes, the fueling may be more complex, but end result would be time invested per shot would be much lower than with cartridges...

Fair point, my contention would be though that 5-10 cartridges would be "enough"

One thing, when we say "hand held", do we mean like a rifle or does that include shoulder fired?

[Hubb]

One thing, when we say "hand held", do we mean like a rifle or does that include shoulder fired?

When I said handheld, I meant any sort of configuration that does not require a stand to operate. This includes rifle configurations, shoulder mounted configuration, "minigun" style configurations, etc. I apologize if this was unclear.