making the blow-forward breech work

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
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jackssmirkingrevenge
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Fri Mar 07, 2008 3:52 pm

I took some photos but the PC decided to crash as I was about to post them and hasn't restarted since, I'm writing this from my other half's PC.

The spring is between the bolt and the barrel, it's not drawn in the diagram but you can see it in the animation.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Sticky_Tape
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Fri Mar 07, 2008 4:06 pm

I was Just wondering.
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jackssmirkingrevenge
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Sat Mar 08, 2008 3:49 am

Here's the bits I have so far, not long to go:
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parts.JPG
hectmarr wrote:You have to make many weapons, because this field is long and short life
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MrCrowley
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Sat Mar 08, 2008 4:13 am

Looks like every other project you've ever made :roll:



:D


Just kidding, it's the dark grey PVC, epoxy covered parts and plain background that does it. :)
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jackssmirkingrevenge
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Sat Mar 08, 2008 4:18 am

MrCrowley wrote:Looks like every other project you've ever made :roll:
Ah, but this one's actually going to work he repeats to himself in desperate need of reassurance :roll:

After all, it is a marriage of two concepts which I've already experimented with, and I'm using the same materials so no surprises there. I just fixed the outer chamber, that and the valve stem should be cured by tomorrow, then I just need to add the valve itself.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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MrCrowley
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Sat Mar 08, 2008 4:34 am

If only your name was somewhat classy like Picasso, you could claim the above picture as art :)
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jackssmirkingrevenge
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Sat Mar 08, 2008 5:42 am

MrCrowley wrote:If only your name was somewhat classy like Picasso, you could claim the above picture as art :)
I could combine the two, but you'd expect someone called "Jackasso" to be more likely to jump across a river in a rocket-powered shopping trolley than make a pieace of abstract art :roll: :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
ROCK SOLID
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Sat Mar 08, 2008 6:03 am

lol home made Machine gun :lol: No pyro ignition
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Antonio
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Sat Mar 08, 2008 7:13 am

Looks pretty pro Jack! I would like to c the final result; I cant wait. Today I am trying to make a tippmann style of trigger and sear.
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jackssmirkingrevenge
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Sat Mar 08, 2008 9:13 am

I just finished making the check valve unit, I could have used a schrader but I thought I might as well make my own :) rather fiddly to put together but the result is great.

Tomorrow morning I'll install the valve stem then glue in the check valve, so it should be ready for testing within 24 hours :) hope it doesn't end in disappointment because after so much refining, I have a real good feeling about this design.
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valvebits.jpg
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Sticky_Tape
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Sat Mar 08, 2008 11:25 am

That's awesome JSR it will most likely work is that a marble that you are using in the poppet valve or is it a ball barring? To tell you the truth I was thinking of the same design for a poppet valve. Nice work!
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Sat Mar 08, 2008 11:29 am

So you recycled the old auto-breach for part of the gun? That's cool. Here's hoping it works!
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Antonio
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Sat Mar 08, 2008 2:40 pm

Nice job on that check valve! Hope it all works out.
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jackssmirkingrevenge
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Sat Mar 08, 2008 3:13 pm

Is that a marble that you are using in the poppet valve or is it a ball bearing?
It's a 4.5mm BB, what strafer lovers call "ammo" :D
So you recycled the old auto-breach for part of the gun?
Only the barrel with its male threaded section, the rest is new.

Here are the parts before I fit the step and epoxy the valve in place. An old friend is visiting from the UK, meaning we have a lovely booze-up planned for tonight so I can't guarantee test results in the morning, but I will bring them to you as soon as I'm sufficiently conscious.
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bfbreechpartsfinal.jpg
hectmarr wrote:You have to make many weapons, because this field is long and short life
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VH_man
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Sat Mar 08, 2008 6:50 pm

wow JSR that poppet valve is MUCH smaller than i thought it was... .177 cal bb as the ball? wow..... are you sure you will fill the chamber up fast enough with that?

anyway, that is looking S**T hot...... the finished product will be much better im sure.
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