Pershing airsoft gun problem
 

Replaced the airsoft gun in my Pershing. The original was jamming. Appears to be no damage to the original gun. New gun is jamming - the bb's just don't travel up the barrel.

Question: is it possible that the aluminum barrel liner has moved forward? How do I seat it into the airsoft gun? Or, if this is not the problem - any ideas on a fix? I have tried better bb's but this does not help.

RE: Pershing airsoft gun problem
 

The HL's won't work if the hole thats about a third of the way up the barrel is blocked. Also don't use the crappy BB's that come with the tank.

RE: Pershing airsoft gun problem
 

Where should that hole in the barrel be position? On the bottom of the barrel, on top, 9 o'clock or 3 o'clocked as viewed from the front?

RE: Pershing airsoft gun problem
 

6 o'clock but I don't use any holes in my airsoft barrels. Why bleed off air pressure and slow the gun down?

When reassembling the gun make sure the breech bushing is seated properly and the aluminum barrel goes all the way back and holds it in place. If it's still not shooting right, make sure you resoldered the wires to the gun motor correctly. What? You didn't break any wires? Here's a medal for ya!!! :D

RE: Pershing airsoft gun problem
 

Because all 3 of my HL's won't work if I cover the hole up, the gun just isn't strong enough and the pellet just stops half way up the barrel.

My Tiger works with the hole blocked up but I've replaced the spring in the gun with one out of a V's gun so it's a lot more powerful.

RE: Pershing airsoft gun problem
 

Must be because of what is known in paintball and airsoft circles as "barrel suck" - a partial vacuum forms behind the ball or BB, slowing it down (in this case, even stopping it). There's not enough air in the piston cylinder to completely displace into the barrel bore to push the BB out. Even as the BB already has momentum to keep moving forward.. in itself starts acting like a piston being drawn out in reverse, especially if its a tight fit inside the bore. The BB may literally stop where the head of the air column stops moving thru the barrel. The bleed hole is not intended to vent pressure out.. but to let air in to equalize the negative pressure. With "barrel suck" eliminated, the BB can keep moving on its own momentum.

RE: Pershing airsoft gun problem
 

Hmmmmmmmm....

Now there's an idea. If you can increase the bore of the cylinder and increase the size of the piston then it'll give the gun more power.

RE: Pershing airsoft gun problem
 

my poor barrel has taken a few direct hits and it still works ok. i know that there is some broken parts on it but it still fires. hope i never have to replace some of that stuff.

also on mato's site there was a complete pershing turret replacement. basically the turret shell, firing mechanism, barrel, etc.

RE: Pershing airsoft gun problem
 

ummmm, this is not barrel suck or negative pressure influence. That is completely wrong. You just have a ****ty HL airsoft gun. Sorry but they are all completely low quality
P.S. that expletive was replaced by some Javascript thing, I actually spelled out ****ty.

RE: Pershing airsoft gun problem
 

That's a rather sweeping statement.. which itself is not entirely correct nor accurate. 95% of us over here have HL tanks with their original stock AS guns.. and we're not excatly experiencing the same problems as being posted here. Whether that's because we're getting better QA, or maybe the guys here have much higher expectations.. I don't know. The power indeed leaves a lot to be desired, my Marui and Acdemy tank guns outshoot them.. but I still wouldn't say our HL guns are all that ****ty.

As for barrel suck. It's a fact. It happens.. though quite dependent on certain circumstances. Why else do you think there's that much discussion in matching cylinder volumes with barrel length when tuning airsoft guns for optimum performance.

RE: Pershing airsoft gun problem
 

Hmmmm BBl length. Perhaps there more to this then one would think. Maybe it is the 1/24 scale and therefor shorter bbls that make the Vs guns develop higher fps then Heng Long. My Panzer III is the best performing Heng Long out of the bunch, and guess what, It has the shortest BBL.

There is really little difference between the Vs gus and the Heng long guns from what I can tell. I got the idea of shimming the spring from the VS gun and have done this on all my Heng long guns. This has helped improve the bunch, and I no longer have any duds.

I am actually quite happy with the Heng long guns now. I know they are pretty lame when compared to the pscartozzi scale, but are now good enough to break paintballs inside 20 ft which is all I ever wanted for tank battling. (Note angled armour works and have have had much trouble hitting another tank and having the things break,on anything other then a vertical surface, making the Tiger the best target tank!!!!!.)

RE: Pershing airsoft gun problem
 

The spring in the Vs gun is thicker and stiffer. I replaced the spring in my HL gun with the spring from a Vs gun and it made a hell of a difference. It'll even work with the hole in the barrel covered up.

RE: Pershing airsoft gun problem
 

80fps versus 135fps.

RE: Pershing airsoft gun problem
 

The velocity of the moving plunger is what dictates FPS. A heavier stiff spring will accelrate the moving plunger faster then a stock heng long. However a shim inside the moving plunger has the same effect. It compresss the spring more, which in turn means more potential energy. Ultimately you are limited by how much torque can be delivered through the motor and nylon gun gears. With stock a spring and shimming I have been able to exceed that limit(.ie sheared teeth of the drive gears), so I doubt much more can be done with a spring. However if a guy could enlarge the cylinder diameter or length, you would expect greater velocities as more compression would occur.

Another thing the dictates the speed on the plunger is how fast air is allowed out through the nipple that sets the 6mm ball in the rubber sleeve. Opening up this hole allows the air to escape the cylinder faster. I did this on my latest gun, which is earmarked for my SU100, and the result actually dented a soup can from about 5 ft when fired on my work bench. As anybody who has worked with these gun will agree they are very finicky. How much the BBL compresses the rubber seal also has a direct relation to performance. Compressing the seal too much increases the friction fit against the pellet. To little and the seal is not tight enough and allows some air to escape uselessly within the gun. For this reason it is very hard to determine what modification has the greatest benefit. Any varible that gets changed slightly has an effect. I am going to try opening up the bore on the plunger nipple on other guns to see if this gain is measurable and repeatable.

RE: Pershing airsoft gun problem
 

True to a point, too thick and the spring wont unwind fast enough to accelerate the piston. Short, fat springs with fewer coils and spacers impart the most energy.

Once work let's up I'll get to do some more Chrony testing.

RE: Pershing airsoft gun problem
 

Sorry, I was having a crabby night:D It's just that you told him that barrel suck was why his bb's are getting stuck. Try this. put a bb in the barrel and hold your finger over the end to seal it. The bb will not slide down the barrel because of the vacuum it is creating, right:D So for a Tiger the barrel has a volume of 5.6 cc's, the piston/cylinder combo is smaller at 5.4 cc. not that different at all

RE: Pershing airsoft gun problem
 

YHR Hi I will tell you this that if the VS barrel was a little longer about 2 inches the gun don't shoot correctly...You guy's are all about now saying yea right hows he know this...Well here is a true story

When the new VS leo A6 came out it had a fault it would not shoot good JUST LIKE THE HL TANKS... And this is why you know how long the VS LEO A6 barrel is ..well when VS released the first version which i bough as soon as it was available what they did was made the full gun barrel out of aluminum and it's much longer than the other stock VS marui gun barrels and because of this the tank shot soft and all crazy like a HL...Well now you ask why i iknow this again...because i complained about it to toyeast and they said they know something was wrong with the A6 gun...and after they found the problem they sent me a new gun and barrel unit it was exactly the same but what they did was drill down the barrel with a drill bit and opened up the inside bore diameter they drilled down into the barrel so the 6mmm boar was the same lenth as all the rest of the stock VS guns barrels where and then it now shoots the same as all the other 1/24 guns...So i guess once you go past a certain length with the BB guns barrel it causes a back pressure sucktion effect and makes the gun shoot weaker.

And this is a 100% true story..don't believe me get a VS A6 the barrel is way longer but the end is board out bigger and down into the barrel to make the lenth the same as all the rest of the VS tanks so the suction back pressure affect don't make the gun weak.....:DMake sure bb is not loaded in gun before looking down A6 barrel...

RE: Pershing airsoft gun problem
 

Let me offer a counter point. A Mad Bull airsoft barrel also has a larger ID near the end then at the breech end. Made no difference in testing with same length barrels with no holes.

RE: Pershing airsoft gun problem
 

Nice fix, drill a hole in the barrel! Seems like it's a pretty good indication that the piston cylinder is designed too small. I think these power robbing 'features' are in place to keep the bb energy to under .1 Joule which they have to do.

RE: Pershing airsoft gun problem
 

Most likely because you can't even compair the power of these tanks guns to a airsoft pistol...I wish mine shot as hard as a airsoft gun!