Project R-77

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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)DEMON(
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Wed Oct 03, 2007 2:36 pm

Hmm, o-rings do not work, I have tried before. Maybe if I cut a seal out of plastic from a milk carton (the plastic ones). The seal inside is very hard, it is not like rubber. I will have to experiment but I can't spend loads of cash on 12grams as they are R7 each. (almost a dollar).

Good news is I have another barrel. All I need now is the weaver rails from my freind, he still has to find them.
Forever dreaming...
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Dornep
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Wed Oct 03, 2007 4:32 pm

)DEMON( wrote:You make it seem like I am fixing the barrel onto the gun with the epoxy, I assure you this is not the case. The putty will form the new body around the barrel. I want this thing to be big, mean and tough.
No I understand that you are replacing the original barrel entirely. I also understand that you want a beefy looking gun too, who doesn't? I get the feeling your going for a look along these lines..
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)DEMON( wrote:I play pump in paintball, so I am used to the ammo disadvantage, no problem for me.
Nothing is more satisfying then one well placed shot right in the goggles..:D

@Jack... Out of the thousands of different firearm companies, how many of them manufacture revolvers with a sealed barrel/chamber system? Besides, unless your shooting subsonic .22 or .45 caliber ammo your not going to be very silent..

I think it's safe to generalise here and there once in a while :wink:
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jackssmirkingrevenge
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Wed Oct 03, 2007 8:38 pm

Dornep wrote:@Jack... Out of the thousands of different firearm companies, how many of them manufacture revolvers with a sealed barrel/chamber system?
at least two :wink:
Besides, unless your shooting subsonic .22 or .45 caliber ammo your not going to be very silent..
Standard 0.22 rimfire and 0.45 ACP ammunition is naturally subsonic, especially from the short barrel of a pistol.
I think it's safe to generalise here and there once in a while :wink:
You're right, of course, but you'll always find annoying pedants like me ready to moan about it ;)
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Fri Oct 05, 2007 9:15 am

Ok, I have started work on this gun. I have carefully removed the cylinders from inside. I need to get the right sized drill bit (8mm)to do any more work.

The maximum size I can make the barrel is 1', thats huge :twisted: But I think I will settle for something a little smaller, buying enough epoxy putty for a barrel that big will cost a lot.

I think I can also do work on the valve. I want to make an o-ring grove (a little metal will need to be removed), to get as little wasted gas as possable. Luckily the valve has more than enough metal to do this on. Wouldn't want any failures ander high pressure.

Will keep you guys updated on my progress regularly.

I may be able to make a hop-up on the gun, where the barrel starts. Will need to do research on that.
Forever dreaming...
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Fri Oct 05, 2007 10:31 am

If yuo want a bit more power (for less gas efficiency) you could always replace the hammer spring with a more powerful one but in this case for airsoft I don't think it's necessary.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Dornep
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Fri Oct 05, 2007 11:17 am

If make a hop up, you want to make sure it can be adjusted after you install it on the gun. If you don't get it perfect it might make your BB's curve upwards or it might slow them down more then you'd like.

BTW what is the weight of a steel .117 BB compared to a 6mm airsoft bb?
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Fri Oct 05, 2007 11:28 am

BTW what is the weight of a steel .117 BB compared to a 6mm airsoft bb
A steel BB typically weighs around 0.3 grams, while airsoft BBs can be found in the 0.12 - 0.43 gram range.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Fri Oct 05, 2007 1:11 pm

Seems the most common is 0.2gr.

Yeh for the hop-up I thought I would glue some tough rubber to the end of a grub skrew and make a threaded hole in the top of the gun where the barrel starts, oviously a little forward though. That should give me adjustable hop-up.

I have also been thinking a lot about a belt fed ammo system. It doesn't seem very difficult to do. I would have to cast it out of plastic or epoxy though. I would have to make a mould of the back of the chamber to replicate the rotation system.
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Mon Oct 08, 2007 8:18 am

Progress update!

The barrel is done! and I did it myself too. I am very happy with it, perfectly aligned.

All I did was get a new drill bit, clamp the gun in my work bench and spend the next good hour and a half drilling through the stainless steal, adding water every now and then to cool it.
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All I need to do now is the chamber and the hop up. The chamber is going to be the hard bit. For the chamber I am going to modify it for belt fed operation, almost exactly like solar's 40mm paintball grenade launcher. I have it planned out but I can't do anything without the epoxy putty.

The hop up will be simple. While I was drilling out the barrel I found that it wasn't a single rifled tube but rather a mass of stainless steel with a barrel bored into it. This is good news for the hop-up because there is stainless steel surrounding the new barrel instead of plastic. The hop-up is mearly a grub screw with rubber glued to it. I need to drill and tap a hole for the hop-up and I am happy it is going to be in stainless steel rather than plastic. It should be very durable.

Because of the belt fed system there will not be a perfect seal between the valve and the barrel but it doesn't really matter. There should be more than enough gas to get the projectile up to speed but I will see if I can sort this problem out.
Forever dreaming...
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Mon Oct 08, 2007 8:35 am

For the chamber I am going to modify it for belt fed operation, almost exactly like solar's 40mm paintball grenade launcher. I have it planned out but I can't do anything without the epoxy putty.
Sounds like it's going to involve some intricate machining but your ratcheting mechanism is already done for you so I'd say it's a feasible undertaking :)
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Mon Oct 08, 2007 8:42 am

It is actually fairly easy but yes, it will require a lot of work. I am glad the ratching system is already done, I wouldn't be able to do something like it myself.
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Thu Nov 08, 2007 3:19 pm

Hay guys. I know it has been a while.

I started applying the epoxy a few days ago and I am starting to get the shape I like for the barrel, will have some pics up tomorrow. This project is looking good. I will see if I can start on the chamber by the end of the month.
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Sat Nov 10, 2007 4:15 am

Ok, here are some pics. You can see the shape I am building up, I built up too much on the front but not to worry because it will be shaped down.

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thoughts?
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Sat Nov 10, 2007 4:31 am

thoughts?
Yes. If the world is heating up at 2 degrees per decade, what is the point of anything?!

*ahem*

Why are you using putty when you could have sleeved the barrel with a larger diameter pipe?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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)DEMON(
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Sat Nov 10, 2007 6:12 am

Best to enjoy life while it lasts, there is nothing much we can do. Evil oil companies and governments think that we can go on living how we are now, ha. The world may be heating up but an ice age will come following the melting of the poles. And there will be war.

*Ahem*

Because putty is structurally more stable and much stronger than pipe. If I just covered the barrel in pipe it will remain weak where the barrel protrudes the plastic of the gun.
Forever dreaming...
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