Posted 20 May 2007 - 08:32 PM
Not as easy as it sounds.
There is no "inner barrel" in pellet guns, pellet guns arn't made cheaply like airsoft guns. They have a solid steel barrel. No way to reem this out to the correct size, so you'll have to buy an inner barrel. hopup unit and make an outer barrel.
First major problem: hopup unit: most feed from the bottom. The 1077 uses a rotary magazine. Which means you need to create a new hopup unit, along with magazine/barrel interface to prevent from losing compression.
power: the 1077 is 8 joules. An airsoft gun barely reaches 1 joule. Big problem. I don't even know if a 1077's valve will function at one joule.
I see people complain about gearboxes. Gearboxes are a walk in the park compared to co2 valves and multishot airguns. Especially a double action airgun such as the 1077. The 1077 is Not semi-automatic, it is double action.
The valve in a co2 gun is very sensitive, change the hammer spring too light and it wont open. Make the valve spring too light and the gun dumps all the co2. You need to find the balance. The valve dosnt open easy like an airsoft pistol, it requires a spring driven hammer to strike the valve stem.
Because the 1077 is double action with a rotary magazine (basically a revolver) Reeming out the magazine won't be easy. Especially since the walls that hold the pellets is very small. You would need to fabricate your own magazine, and reduce the number of teeth on the wheel so that it cycles and indexes correctly. Without a mill, you will never be able to make this.
I see this project as nothing but an exercise in fustration. The 1077 design does not lend itself to change in calibers.
While possible, unless you have a lot of skill in machining, and working with airguns, you'll probably end up with a bag of parts.
The only possible converson from airgun to airsoft gun I see is in .22 caliber airguns. There is only .5 difference. One gun in particular, the Crosman 38c.
The gun actually does have a two piece barrel, though it's inner barrel is substantially thicker then an airsoft inner barrel. Spacers could take care of this. There is no room for a conventional hopup unit, so you'll have to make one yourself. (Rubber sleeve with BB in place. Drill a hole in the outer barrel, tap a screw to adjust hopup.)
The magazine is hardened steel, but it can be reemed out. The well to load the pellets might also need to be reemed out.
Get the barrel and magazine sorted, you need to look at reducing the power next. It shoots about 5-7 joules. The hammer spring could be softened untill the power was low enough. You might have to drill holes in the hammer to lighten it.
then you are done. You'll have a 6 shot revolver that will shoot in excess of 600 fps with the heaviest bbs you can find.
I actually have a 38t. The problem with doing this however is the 38t stopped production about 25 years ago. Anything you find now will be mint condition and very expensive, or non functioning and requiring a reseal.
The 38t is one of the most difficult guns I have worked on, quite a bit more difficult then a gearbox.