TM MP5 A4 Hop-Up Question

[rickj1]

Bought my first airsoft gun!! A TM MP5 A4 HG from Mike at Wolverine Tactical. (He should be considered a credit to this sport - by the way. Very nice guy - and a pleasure to deal with.)
After learning how to operate the gun, my son and I proceeded to "rip up" the included paper targets, foam cups, tin cans, and finally Ritz crackers. We had a blast.
After about 400 rounds, we called it a day and the whole experience left me with two "Problems".
First, my son got to shoot HALF the time. This obviuosly means I wasn't shooting ALL the time. I plan on fixing this "serious oversight" with another gun order from Wolverine.
Second, is a legitimate question concerning the use of the hop-up on this gun. The actuation lever is on the cocking lever side just above the rear of the fore-arm. Lever toward muzzle = no hop / Lever toward butt = max hop.
Here is what I discovered about his gun...
BBs fly in a large vertical arc up when at max hop.
BBs fly straight at about 1/2 setting.
BBs fly in a short downward arc (almost seeming under powered) at a low (but not quite OFF) setting.
Now for the question...
With the hop-up lever OFF (ALL THE WAY toward the muzzle) the gun doesn't shoot at all. After a few experements I discovered I could shoot as mentioned at any of the other settings with 100% reliability but as soon as I shot in this OFF position nothing happened and if I tipped the muzzle down, after the shot, a BB would come rolling out the muzzle.
I know the obviuos answer is "Don't shoot it with the hop OFF then- Dummy", but I was just curious if this is common or normal and why it happens.
I'm sure the good folks at WTS would have answered this, but I wanted to register for the forum any way.
By the way - I am in no way unhappy with this gun and my tracer unit should be here any day!!!!
A duplicate post was put in "Newbie" - Wasn't quite sure where it belonged.

[Minky]

Hey rick, welcome to the forums! Glad to see a parent taking an active role in airsoft with their child, and discovering new targets for me to shoot. I'll have to try the crackers someday soon.

Anyway, on to your (second) problem. The hop-up behavior you're describing sounds right, except for the gun not firing at all with no hop on. Every gun I've ever seen will still fire with the hop turned all the way down, since there's no reason it shouldn't fire. I honestly can't think of a reason why your gun would shoot fine with the hop turned on, but not with it turned off. The only thing that seems like it could be at fault is the loading nozzle at the front of the gear box, but even that doesn't really fit your symptoms.

When you have your hop-up ideally set for the longest, flattest trajectory, what kind of distance are you getting before the BB drops and hits the ground? Even on a stock, short barreled gun you should be able to "float" BBs out to 100 feet or so. If you're getting much less distance, your nozzle might be unseated or cracked. You can check by looking into the magazine well of the gun. You should be able to see the tip of a part looking like this www.wargameclub.com/pcart/shopper.php?itm=GD-PT-GE0426_cat_Guarder Parts for AEG&PHPSESSID=629cbe62679d7cc4fa7b670b45338ab0 . See if you can spot any cracks in it, and make sure that it's moving back and forth each time the trigger is pulled. It moves fast, but it should be obvious if something is wrong, as it won't move reliably if it's come unseated from the tapet plate.

Other things to check/try: Use the unjamming rod that came with your gun to make sure you don't have any BBs stuck in the barrel; clean your barrel as per the instructions in your manual; check your magazine to make sure it feeds reliably; make sure you're using high quality BBs of at least .20 gram weight with no burs or odd shapes.

Hopefully somebody else might have more ideas, because I'm truly stumped. Maybe it's because I just woke up though... ;D

[Jacko]

If the hop-up is completely off, then there's nothing holding the BB, right? Now, if that's true (And someone correct me if I'm wrong) couldn't the BB be simply rolling away from the nozzle and, as stated, roll out of the barrel?

That's the only thought I had.

And welcome to the boards, rick! It is nice to see a parent being proactive and getting involved and you should be commended for that.

[rickj1]

- Nozzle looks good.
- "Floats" BBs well out to 100 feet.

As I stated before, I had ZERO misfires (except 1 ea. after inserting a new mag - I believe this is normal??) No problems at any other hop-up settings other than fully toward the muzzle - "off". The "problem" only occurs when in the full forward position. Is there such a thing as to far "off"?