So let me get this strait... You'll use a solenoid engine of an airgun modified to fire 6mm bbs, correct?

If this is the case I'm VERY interested.... Or let me refrase I'm interest in anything you'll build!


Wolf

 

I don't think he's talking about bbs..
More like airgun ammo.

 

I dont know if pointy ammo is safe for the (quite substandard) safety glasses people use...
Also, i've seen .30g bb's going into the skin. Imagine what pointed ammo would do?

Perhaps softammo would do the trick?

 

Would be very interesting to see a company manufacture bullet-shaped BB's along with a propietary mag and hop up system (well, feed unit is more like it) and see how it does with a Tanio-Koba. :yup:

 

A .125" radius on the nose will actually make them less pointed than the current BB's. I understand the knee-jerk reaction but I was a little offended that you thought I am that irresponsible.

George, you flatter me. This will be much more simple. This will be taking a very accurate air rifle, turning down the power and then loading it with hand made rounds or BB's.

My current project is indeed an air engine that is solenoid controlled and fires 6mm BB's. It is even programmable. I can set it to semi, full auto, progressive, and even 3 round burst

I love coming up with this stuff.

 

You can't have a hop if the ammo isn't a ball. Actually you wouldn't want it. The barrel is rifled !!!!

 

Hence why I parenthesized feed unit :tup:

By the way, must be nice to be in central NC, at least you got a few fields; right?... Lousy east coast.

 

Oh I see... Well check this out.

The bbs... The black one is used, they have some micro-fin at the back end.

And the gun that uses this barrel and bbs

It's the mighty Asahi M40!

There was a discussion for nonspherical bbs here:
http://forums.airsoftmechanics.com/index.php?topic=5851.0

Wolf

 

What kind of accuracy does it have and what happened to Asashi?

Paul

 

Rubik, where are you in NC?

 

Well... To be honest never really tested it! I've fired it some times but after a few load... reload it's kinda boring.


Wolf

 

That's exactly why I like the 8round mags on the air rifles.

Paul

 

Between Morehead City and Jacksonville. About a mile from the ocean. Freaking air rusts all my stuff. There's one field where the marines on Lejeune play, so I may try that out. But one tiny shop (2/3 hobby, 1/3 airsoft) in J-Ville, run by one guy, who usually gets stuff the same time as ASGI. But no BAR 10's in his shop yet...

 

Wolf, now that you told us about how that Asahi works you gotta test it out for us LOL.

@Builder- I can see why you chose that user name, it suits you. You have some really awesome builds going on.

If you look on Hunterseeker's website (you can find it through Cheese's website) you'll see he actually sells asymmetrical 6mm rounds, with the fins on the back. He sells them through shapeways, though they're a little cost-y.

From your descrption of this build, it seems you are going to need a lot of power behind those rounds to get them to go through a rifled barrel. Plus even with side spinning rounds, you're going to need a lot of fps to get them to the target before gravity pulls them to the ground.

I said a while ago that real steel rifles don't shoot in an arc. After some more researching I found out I was wrong, so whoever I told it to, sorry about that. Rifles' barrels are actually aimed slightly up so it is easier to ge the bullet to be on the cross hairs' center at a given distance. otherwise, teh bullet would drop to the ground the second it leaves the barrel and there ould be no point where it crosses the center of the cross hairs of the scope.

With this setup you will also need to learn how to read mils on a scope, because even though we are working at relatvely short distances, the low velocity of the rounds will make it seem much longer. Tell me if I misread anything you said.

 

I said a while ago that real steel rifles don't shoot in an arc. After some more researching I found out I was wrong, so whoever I told it to, sorry about that. Rifles' barrels are actually aimed slightly up so it is easier to ge the bullet to be on the cross hairs' center at a given distance. otherwise, teh bullet would drop to the ground the second it leaves the barrel and there ould be no point where it crosses the center of the cross hairs of the scope.

With this setup you will also need to learn how to read mils on a scope, because even though we are working at relatively short distances, the low velocity of the rounds will make it seem much longer. Tell me if I misread anything you said.

A good book that talks briefly about the arc you are talking about is "Sniper" by Adrian Gilbert. It's a fun read over all about sniping and it's history as well.

"When a 7.62mm round is fired at...a distance of 300 metres it's culminating point is only 6.7in above the line of sight...and at 1000 metres the culminating height is an extraordinary 129in above the light of sight..."

 

I tend to go for simplicity believe it or not. If I can get a round to track really straight the drop can be calculated.

I could be mistaken but I believe the rotation of the round and the shape will help to flatten the trajectory some. Not having a hop to deal with will make accuracy and velocity tuning much easier.

By having the rifling in the barrel and not on the round it will also increase range. There are Paint balls that have fins and they fly really straight but they do drop hard due to the fins causing drag. If the round is smooth but spinning it will hold it's speed longer

As for power, I am concerned more about getting the velocity down. These rifles can produce over 60joules with lead rounds. But, since they are poppet valves they are very tunable.

 

What I'm saying is you probably won't be able to get the velocity down. Ubless you engrave the rounds before hand to fit the rifling, you are going to need a lot of power to push the materal of the round through.

 

I forgot to mention I appreciate your comment on my screen name. I am a builder at heart, I live to build, design and fabricate.

Since I am molding the rounds I can undersize them slightly so they will move easily and if some air does escape around them it should help them spin.

I really appreciate all the input because I want to discuss this fully before I drop the $$$ for the rifle.

Paul

 

Unless the rounds are really rough, escaping air will not help them spin. The air will follow the path of least resistance, and most of it will end up going around the round. In order for the rifling to work properly, you will need to have the round fit in nice and tight.

The only way I can see this working at low velocity is with a really soft and slippery round. I would love to be proven wrong though.

 

This is exactly the kind of conversation I need before I drop $500 for the base gun. I can get all kinds of two part "plastics" from the different vendors I use. They will give me lubricity and hardness so if you guys have some numbers I could start with that would help. So, you are saying I am better off rifling the round.

For those of you who have shot archery or flown high power rocekts you know how little it takes to effect flight.

Some of the materials I have in mind are actually used to make very slippery molds that can flex so this may be just the ticket.

George needs to give us some accuracy results from his Asahi rifle to indicate if this is worth pursuing.

Back in the late 80's there was a Paint Ball gun builder (I had one of his rifles..OUCH) who played with oblong rounds with no fins at all and even that flew better than a round ball.

I just cannot get it out of my head that we are leaving a bunch on the table. Since we are not really concerned with rate of fire it seems there is so much more we could do to improve the equipment we use. I can't help but feel like all we do now is put patches on a broken system.

Spring pistons are not the worst part of the equation. Yah the amount of energy that gets lost in the system is absurd but that is still not the worst part of the deal.

The BB itself is what's killing us !!!!!

Maybe I need to start with the rounds I have in mind and build the system from there.

Let's go folks step up and give me some input. If we stick with 6.35mm by 9mm there are magazines already available.

Paul

 

Any excuse to show off your Asahi, eh George?

 

I'd love to... But the current weather conditions are not allow it and I don't have a long enough building around to go and test it!

It can shoot pretty hard... It supposedly has a good accuracy and range with the Magna barrel and Blade Bullets (some say over 100m!).
But from some test I did when I got it the consistency is not so good, with the same amount of pumps it gave me different fps per shot with the same bbs.
I havent test though to fill each time the same shell to see what fps will give me...

So it's not a reliable base for such test.


Wolf

 

I did not realize it is a "pump up" gun. That alone can really mess with consistency.

In my limited experience I would say HPA or CO2 are the most consistent methods of propelling a projectile. Once the air system is sorted out the valve needs to be consistent. A poppet is probably the most consistent and reliable. When I build another gun it will be a poppet valve. I am not sure if it will be a BAR or a Semi but it will deff be a poppet valve.

There are a number of poppet style PB guns that could easily be converted.

Paul

 

Well, kinda pump action. You see, you need to pump air into the mock shells themselves. Go to 1:59 in the video.

 

Wow. I can see how that could get annoying. No wonder it isn't field-able.

@Builder- I wouldn't say it's a broken system, just an imperfect one. Hopup seems to be the only way to get these kinds of accuracy without creating a gun firing plastic bullets. Like I've been saying, unless you somehow have a VERY soft outer layer on the rounds for the rifling or you somehow put counter rifling on the rounds so the barrel rifling doesn't have to cut in, you aren't going to be able to use low fps. I can't guage how much you would need though because that depends on the material the rounds are made of.

the hopup system is very crude, only giving us short range accuracy, but it's the only one that gives us the flexibility to use fps as low as 300 and still get the same accuracy. Without the magnus effect holding the bbs up, they would fall to the ground long before 300 feet, even with a side spin. I'm amazed we've refined it as much as we have quite honestly. And I still can't believe the accuracy Cheese gets, or how much time he put into getting that accuracy.

 

Correct, the one Scaar uses in the video has a AS4L hop up and a regular barrel, mine was upgraded by Asahi and came with the "extra" hard shells and the strait rifled Magna barrel.
That's why Scaar saying the Blade Bullets won't fit in his shells!

It's really annoying to do this all the time, and imagine to pump 10 times in each of the 30 shells I own! It's gone take some time.

looking forward to see how this will go.

The tester for HS5's "bullets" was EDI1st and he used an upgraded G&P SR25, to load a "bullet" he removed the rear pin, split the gun in half and feed it manually in the barrel.

I personally don't like the airguns loading system as after a few shots the pellets won't stay in place properly, I didn't like the HW100 system as it's the only PCP airgun I've used so far.


Wolf

 

Juggler, your description is much more accurate. It really isn't broken.

Okay so we start with a "rifled" round and build the system around the round. Since there are both 6mm and 8mm rounds available staying with 6mm sounds good to me.

George has experience with PCP airguns and the mags have some issues. Honestly that type of mag would be more difficult to design around so a simple spring mag makes the most sense.

A poppet valve seems the best way to go. The sound signature can easily be dealt with using the outer barrel.

Should the air system be within the gun or are we big fans of remote lines. It it is a BAR a single 12g CO2 cartridge should yield 50-60 nice shots.

Sound good so far?

Paul