Best GBB pistol

NH Shooter said:
Kind of... You can buy new ones, upgraded with metal slide, upgraded barrel, loading nozzle and hop rubber for only £55 extra... And the slide doesn't really affect anything. Mine, out of the box, out ranged (more accurately) most modified pistols... Even with its standard slide. Fires a nice 270fps or higher on green... The metal slide conversation would make it an excellently durable pistol. Not that it isn't already...
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the plastic slide is what makes all the difference, weight is a huge issue; the boiling off of your gas is what provides the energy to propel the BB and cycle the slide, the heavier the slide the more energy this takes and therefore the more gas needs to boil off to cycle it. Not only that, a heavy slide (metal) will cycle slower because gas boils off at a flat rate.

THAT is why marui pistols with plastic slides perform better than other brands with metal slides... physics.

 
Which is why mine stays plastic... I was just pointing out options. But worth noting again... Is that by increasing gas pressure, you offset the increased inertia to a varying extent. Remember it's an unregulated system though... It doesn't actually use more gas. The energy needed to cycle the slide and project the round isn't balanced against the mechanism... So I'm not sure of a loss of power when using high pressure gasses. I'd need to check, but I think slide velocity dictates the gas useage... I know it did on a recent sig rebuild... I'll have to check the hi capa.

If its the same type of mechanism, I think the math would add up. I'll have a look tomorrow.

 
Ok well I'm not having much luck in finding a decent ww2 co2 GBB so let's throw this open to all co2 nbb or GBB and ww2 is not essential!

 
Ok I seen one my supplier has and it's a WE XDM 3.8, any good?

I know it's not co2 bit I would buy the bulk Coleman propane cylinders anyway if it's a good gun.

 
NH Shooter said:
Which is why mine stays plastic... I was just pointing out options. But worth noting again... Is that by increasing gas pressure, you offset the increased inertia to a varying extent. Remember it's an unregulated system though... It doesn't actually use more gas. The energy needed to cycle the slide and project the round isn't balanced against the mechanism... So I'm not sure of a loss of power when using high pressure gasses. I'd need to check, but I think slide velocity dictates the gas useage... I know it did on a recent sig rebuild... I'll have to check the hi capa.

If its the same type of mechanism, I think the math would add up. I'll have a look tomorrow.
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this is unintelligible gibberish, I'd be extremely surprised to hear you were sober when you vomited this stream of just-about-consciousness onto your keyboard.

It's simple physics:

Propane boils from liquid (in magazine) to gas (valve open) at a fixed rate

The valve on the magazine DOES NOT CLOSE until the slide has cycled back far enough to reset the valve knocker

A 50gram metal slide requires twice as much energy to move as a 25gram plastic one, it also accelerates slower.

The energy input, from the propane boiling is a constant rate of X joules per gram that boils off, which we can equate to X seconds of the valve being open since the boil rate is (functionally at least) constant.

Because the metal slide needs more energy to cycle it requires more gas to boil in order to do this... so gas usage with a heavier slide increases.

Not only that, generally with a heavier slide you'll also need a heavier recoil spring to keep the gun cycling at an acceptable rate which means EVEN MORE energy is required to push the slide back to the point where the valve knocker is reset.

Lighter (plastic!) slides are MORE EFFICIENT and use less gas per shot than metal ones.

 
That's only correct in a balanced system, where the force supplied is equal to, but does not exceed the f I races required to cycle the system at the defined velocity. So basically, f=ma. If f>ma. The system is overpowered. At that point, to balance the system, you need to increase the mass or acceleration.

Your spring comment then becomes f=kx-ma. But that still assumes a balanced system.

Your comment also hinges on equal energy and force. If change the force of the system, you would equally need to balance the mass, and spring force... Or slide and recoil spring.

But there no reason to get so aggressive over it, son.

 
What's not to understand? ... Their a simple gas piston mechanism. The science is roughly 1920's technology.

Breaking down the entire conversation...

- They have plastic slides, break with propane

- Use metal

- But lower power

- No... Slide heavier, but more power in propane. Weight up, but also power up... Equal... Balanced

- You don't understand physics.

- Here's some simple physics and "Newton's first law"

- No, you don't understand the mechanism.

So... I'm not sure there's any point in continuing this conversation at this juncture. I've spent the last 3 years simulating/testing gas flow, pressures, gas expansion, stress, strain, mechanisms and complex engine dynamics... Which is exactly this in terms of the science... But I'm happy if you live with the idea that I don't know what I'm talking about if it brings this conversation to an end.

I don't want this to be considered an admission of failure to give the correct information, but for those reading at a later date, they should have a rough idea of why I didn't engage further...

 
ok, it seems you've been arguing something that was settled on the previous page... TM pistols are perfectly usable with propane.

oh, and since you're such a physics whizz, but clearly not so hot on reading comprehension, you should also have picked up on me using the boiling rate of propane as a constant; i.e. work to the assumption that propane would be used in both guns, at which point the plastic slide remains more efficient because it weighs less!

 
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ikarma70 said:
Ok I seen one my supplier has and it's a WE XDM 3.8, any good?

I know it's not co2 bit I would buy the bulk Coleman propane cylinders anyway if it's a good gun.
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No relation to what you said, but the salient arms slide kit for the xdm is gorgeous although it's for marui I think. I would see up for a marui and reap the benefits after :)

 
Not sure if relevant, but replaced a customers plastic TM Glock 18 slide (which worked very well on WE gas) with a ACE1Arms Salient slide. It proceeded to work very well on exactly the same gas.

The thing about airsoft is that there is a LOT of chairsofting and theoretical talk and very few people actually willing to go out and achieve or experiment with stuff.

Theoretically the metal slide should perform 'worse' than a plastic slide, but often there are more factors to consider than just 'metal is heavy hurrrrrrrrrrrrr' (which, I admit, is a theory that I am a subscriber to)

 
M_P said:
The TM 1911 is the only one worth buying two_zero. The mags are so small that only the light weight plastic TM slide is efficient enough to be worth while.

NH Shooter, all tm 1911 frames a plastic too, hicapas are metal though, your right on that
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ah yea.. think I got it a bit mixed up there because of the metal.

thou still my reaction to "mags doesn't hold enough gas for a metal slide" would be "or you could get a gun that holds more gas". Each to their own thou :)

 
I bought a kwa glock 19 with full trades in good condition.

Decided to go green gas as I am looking to use Coleman propane if I can.

 
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