Black Fox's Tricks of the Trade - The Golden Secret

[Black Fox]

Have you ever noticed that some guys guns just always seems to out gun yours? Or that they always seem to have a bit more sting to them. There is a reason for it and I’m about to tell you why. I’ve given some hard though about sharing this trick of the trade. But since I don’t live in this area I really don’t have to worry about going up against any of your guns. With that in mind I will share with you what I consider is the Golden Secret of the airsoft trick of the trade.

This secret has been around for some time but one that has not really been understood. Because of that, airsofters in general have not paid much attention to it. What I am talking about is matching your inner barrel with the proper cylinder to the spring and BB weight you are using. This combination more than any other upgrade you do to your gun will determine how potent your airsoft gun is. Done properly, you will maximize the energy and the range of your BB. In short, you will be able to out gun most people on the field. Done improperly, your gun will act as an airsoft vampire that will drain or prevent your BB from reaching its maximum energy potential when leaving the barrel. I’m going to help better understand this aspect of airsoft technology.

Before we start. First, I want you to go to this link http://www.cobraairsoft.com/default.php?cPath=79_80 and look at the Systema cylinders labeled “Type-0â€

[Archangel 06]

Black Fox, that was some excellent research and explaining you did there. It would have been very easy to make that subject far more involved than you did, and you kept it at the right level.

Congratulations on an excellent guide, and thank you.

[Patrick750]

when I googled "Prometheus Stainless Hard Cylinder (A)" it came up with that and "Prometheus Stainless Hard Cylinder (A) ver. 7" will they both give me the same results?

[Black Fox]

Thirded for the sticky status. Black Fox, that was some excellent research and explaining you did there. It would have been very easy to make that subject far more involved than you did, and you kept it at the right level.

Congratulations on an excellent guide, and thank you.

Thanks Archangel 06.

This actually took me much longer to write then I expected. You are right. One could easily go off the deep end trying to explain all the variations and physics involved. I'm sure most airsofters aren't really interested in that. They want to understand enough to be able to tweak their guns. Also, trying to make all the information flow to make the most sense out of it all took some time as well. I had to revise it multiple time to get it to this point. There are still a few point that I need to tweak but I'll get to it when I can.

[Limpy]

It seems like everything you post should be stickied.

[Boots Guy]

What about the bore up versions? Would they work the same?

[DMitri]

Let’s say you have 3 identical M-4 and all of them have a 363mm inner barrel. The only difference is the cylinder they are using. Gun-A is using a Systema Type-0 cylinder, Gun-B Type-2 and Gun-C Type-3. Now let’s say all guns chrono at 400 fps with a 0.20g BB. Since they all chrono the same, one could conclude that they would all shoot at approximately the same range. Wrong! Gun-B would significantly outgun Gun-A & C. Why is that? First let’s explore why Guns-A & C doesn’t shoot as far.

Verify the orange text with data, please.

Gun-A: The reason Gun-A doesn’t shoot as far as Gun-B is because the BB is leaving the barrel before it is reaching its full energy potential. Because the cylinder is so long, it has way more air than the M-4 inner barrel needs. On top of that, the piston doesn’t reach full speed until just a split second before the piston impact the cylinder head. Because of this, the BB is pushed out of the barrel before the piston head impacts the cylinder head. As a result, the remaining air is wasted energy and the BB does not reach its full speed potential because the transfer of energy was not complete. The reason full cylinders are used on long barrel guns such as an M-16 is because the long barrel gives the BB more time to reach its maximum speed.

The moment the piston is released to the moment it strikes the cylinder head is a 'split second' in every replica.

I'd like to see the numbers on this, and not just a pre-established theory restated in a wall of text.

Also, the statement in green makes the statement in red irrelevant. That's assuming it is even true--again, you didn't provide any data. That's why it's important to run experiments and not just turn hypotheses into 'facts' by plugging in arbitrary numbers. In the above text you stated that Theoretical Replica A doesn't shoot as far regardless of having the same initial velocity, then in the following text, you imply its lack of range is precisely because it didn't have the same initial velocity--which is it?

[Blizzard]

Interesting read, thank you for taking the time to write it up. I will let some other people argue out the logic behind this theory (as stated by DMitri), but I would like to know two things: Do you actually go through this entire process with your replicas, and what is the range "boost" (compared to the stock replica) when the "perfect" setup is acquired?

[Black Fox]

DMitri

You're right? The cycling on the piston all happens in a split second. In reality the difference of piston stroke between an M-4 using a ported cylinder and an M-4 using a full cylinder may only be a hundred or thousands of a seconds difference. I will take a look at it and see if I can rephrase it more clearly. If I were a graphic artist. Explaining it would be a who lot easier.

Unfortunately I don't have any hard data to back up what I am saying. I have a chrono but I don't have the kind of equipment that can provide the data that I think you are asking for.

However, I've personally have experimented with many different combinations of using full and ported cylinder over the years. All I can say is that matching the correct cylinder with the length of the inner barrel that you are using does improve your range.

As for the explanation I gave above. This is how it was explained to me from a friend of mine who worked at Systema for many years.

[Black Fox]

What about the bore up versions? Would they work the same?

Full Bore-Ups cylinders are only really effective with barrels over 550mm.

Ported Bore-Up cylinders are only really effective when using high-power springs such as M-130 or higher. In most cases guns that use an M-130 usually shoot much higher than 400 fps. Since most fields that have 400 fps limits, you won't really get any benefits from using a bore-up. However some very short barrel guns that use a barrel that is 250mm or less, generally require an M-130 spring to push the fps up to 400 and may benefit from using a bore-up cylinder.

[Black Fox]

Interesting read, thank you for taking the time to write it up. I will let some other people argue out the logic behind this theory (as stated by DMitri), but I would like to know two things: Do you actually go through this entire process with your replicas, and what is the range "boost" (compared to the stock replica) when the "perfect" setup is acquired?

AsianMarksman

When I'm doing a cylinder upgrade I will usually buy two different cylinders that are recommend for the length of the inner barrel that I'm using. For an example, for an M-4 I might get a Type-1 and Type-2 and see which one offers the best velocity. Another example I recently upgraded my M-4 363mm to a 407mm. If you use a Prometheus barrel is recommends a "B" cylinder (401 - 450mm) but I also got a "C" cylinder (301 - 400mm) since it was so close to 400mm. I tried both and in this case the B worked better.

Unfortunately there is no formula that I know of that will tell you which cylinder is going to give you the best performance. You just have to start with the ones that the manufacture recommends that is the best for your the inner barrel that you are using and experiment from there.

By the way, in the other thread you said one of your guns shot fairly accurately up to 60 yards and 70 if you arched it a little. That is actually very good and is very close to the maximum range if you are going by 400 fps rules. The best I've had one of my guns do was 75 yards.

[Blizzard]

Thank you for taking the time to write this all up. I don't quite understand all the logic behind it, but I guess I'm just going to have to try it out for myself and see what happens!

[DMitri]

I'm only contesting the implication that too much air volume in a cylinder will cause a replica to be out-ranged by another replica with a volumetrically smaller cylinder in relation to the port, but that still manages to produce the same velocity regardless. This makes the only variable the volume of air, making your claim appear to be that too much air is detrimental. Without data this is hard to rationalize.

It could very well be true that the velocity will change between the two as a result of a plausible millisecond of increased resistance on the piston. The increase in velocity would, by extension, increase range--and even accuracy to a lesser degree. If that were the case it makes sense for Tokyo Marui and the like to include them in their replicas. But given that we have an artificial cap on velocity anyway--which is commonly reached, the argument appears moot to me.

Is it not also feasible, that if the time the piston travels were actually negligible between the two replicas, that it would result in greater air/bb velocity with the same energy needed to cycle the replica, given the amount of air in the cylinder is greater but still is compressed into the same amount of space in the same amount of time? I believe this is the concept behind "bore-up" cylinder setups. This would suggest that an unported bore-up cylinder set in conjunction with a tightbore inner barrel, would be the best first step to reaching the velocity cap, in order to lessen the requirement of the spring which increases strain on numerous parts and overall energy consumption, along with reducing rate of fire.

Data, my friend--it's crucial.

To look at it from yet another perspective, I said a long time ago that I'd be interested to figure out the affect that a ported cylinder has on the longevity of the o-ring, especially in replicas which also have ported piston head, along with other issues like expelling grease.

So, for the time being, for all the reasons listed above, I offer my own hypothesis that an unported bore-up cylinder is the best route to take for all replicas which are headed for their velocity limits, and possibly even without that requisite.

[CommieHunter]

DMitri, is it possible that the excess air from a full cylinder on an M4 barrel causes extra turbulence right when the BB exits the barrel?

[DMitri]

I'm not a physics expert by any stretch of the imagination, but I'd think the air would need to be capable of moving quicker than the air which acted on the BB and the BB itself for that to happen.

Visualizing it in my head, I'm led to assume that by the time the BB is expelled, you've already reached peak potential velocity.

I also think such an affect on the BB would alter its trajectory/accuracy and not just the range, I can't really fathom how range would be affected at all otherwise, given we're talking about increased volume and possibly velocity of air. I haven't heard of any wacky flight paths being caused by unported cylinders.

Again, this is just conjecture though. I don't want to do the very thing I'm being critical of.