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jackssmirkingrevenge
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Wed Mar 04, 2020 11:40 am

Xamllew wrote:
Tue Mar 03, 2020 4:33 pm
I had a similar idea for a valveless, except using a mechanism like a Quick Disconnect air hose fitting to lock the projectile in place.
Something like that:

Image
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Xamllew
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Wed Mar 04, 2020 11:44 am

jackssmirkingrevenge wrote:
Wed Mar 04, 2020 11:40 am
Xamllew wrote:
Tue Mar 03, 2020 4:33 pm
I had a similar idea for a valveless, except using a mechanism like a Quick Disconnect air hose fitting to lock the projectile in place.
Something like that:

Image
Exactly. Did you ever get a working prototype built?
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jackssmirkingrevenge
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Wed Mar 04, 2020 12:20 pm

Yes, to a point:



It just need a lot of force to operate even with relatively low pressures.

You would definitely need some form of strong hammer to set it off. Since I was looking at blowback mechanisms, I did not proceed with it as too much hammer strength would make blowback impossible.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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jrrdw
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Thu Mar 05, 2020 7:03 am

Xamllew wrote:
Tue Mar 03, 2020 4:33 pm
@JRRDW, could you explain what you mean by air getting around the projectile and slowing it down? What I had in mind was a barrel diameter that narrows by less than a millimeter, going from decently airtight, to requiring a few tamps with a ramrod to fully seat.
If the projectile is air tight from chambered to exiting the muzzle it removes the issue from the equation. Any less of a seal could leak the pressure of gasses used to launch the projectile.
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Xamllew
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Thu Mar 05, 2020 12:47 pm

jrrdw wrote:
Thu Mar 05, 2020 7:03 am
Xamllew wrote:
Tue Mar 03, 2020 4:33 pm
@JRRDW, could you explain what you mean by air getting around the projectile and slowing it down? What I had in mind was a barrel diameter that narrows by less than a millimeter, going from decently airtight, to requiring a few tamps with a ramrod to fully seat.
If the projectile is air tight from chambered to exiting the muzzle it removes the issue from the equation. Any less of a seal could leak the pressure of gasses used to launch the projectile.
Ah, i see what you mean. My dimensions would ideally allow the projectile to slide down with little effort, but then require a force of maybe 10lbs to seat the projectile into the constricted section at the bottom.
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farcticox1
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Sun Mar 15, 2020 3:36 pm

For a spring powered airsoft would a short stroke large bore piston work as well as a smaller bore piston with a longer stroke if they had the same displacement volume ? I'm thinking the larger bore piston would need a heavier spring but would be more compact length wise.
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mrfoo
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Mon Mar 16, 2020 2:32 am

Porting and piston form is going to be important to get air out of a short, squat, cylinder into a long, slender, barrel in a hurry. The big issue is, IMO, going to be changing the direction of the air, as such I'd probably go for a conical piston face mating to a conical cylinder end, with highly radiused and polished port(s). Which loses some, or all, of the advantage in terms of compactness.
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farcticox1
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Sat Mar 21, 2020 10:32 am

Anybody know the bolt pull/cocking force required on a typical airsoft sniper rifle? trying to get an idea of spring strengths I may need for a 100mm stroke piston, I have read that one has a 95mm stroke but can't find any force required data.
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wyz2285
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Mon Apr 27, 2020 5:38 am

Any one could tell me whats these holes on the baffle are for? Like why isn't the hole/cut mirrored? Wouldn't' it cause non uniform turbulence?Image
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
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