Questions about certain parts in my airsoft guns.

[Jbone 11 11]

A question about Hop up: I have an M4 (G&P metal body and Hop up insides), when I pull back the Charging Handle and the bit in the ejection port pulls back, I see the Hop up wheel/Gear (Blue) and was wondering what exactly its for?

Also, I just bought a KSC Sig P226 GBB and it came with a little key of sorts, and from what I can make out from the all Japanese manual (!) its some how related to adjusting the shot characteristics.
Could anyone shead some light on that?

So yeah, a couple of super noob questions there... ; )

J

[Erennert]

I'm an not sure about the pistol question, but hop-up is designed to put back-spin, to change the direction of the BB, to account for wind resistance.This way, you can change the hop-up of the BB, and create a nice straight path, even with wind.

EDIT: Only back-spin

[viraL]

The hop up, correct me if I'm wrong, is intended to put backspin on the BB. Try taking it out for some shots and playing around with it in between shots. You'll be surprised to see that you can increase your effective range just by dialing in the hop up. Too much and they fly upwards, too little and they don't do anything. Just right and they stay straight for a nice while.

No idea on your second question never owned/worked with a GBB.

[Disco_Dante]

The key that came with your GBB is most likely the hop up adjustment tool. Most GBBs don't have an externally accessible hop up, so they have a little key that you use to adjust it.

[Qlong]

The little blue wheel adjusts the hop-up. There should be a little word "hop -->" on the wheel, this indicates the direction you turn the wheel to put more of a back spin on the BB.


The little key adjusts your hop-up inside the barrel when the slide is locked back, just match the grooves on the key with the grooves in the barrel and turn (I forgot which way to adjust hop-up)

[m102404]

When you look at the ejection port area on your M4, you see the front of the mechbox and cylinder and then the hopup unit in front of it.

The hopup unit has 3 dials/gears on it...the far right top one might be a bit hidden. Only adjust the bottom/left one...it'll turn the others.

Turning clock wise put on more hopup...turning counter clock wise removes hopup.

Hopup is added or removed by lowering (on) or raising (off) a rubber nub that protrudes down into the inner barrel. Imagine a straw...look down it...you see a tube. Now sqeeze/pinch the straw a bit and look down it. There an indent where you're pinching. That's exactly what the hopup unit does...it pushes against a rubber sleeve that sticks into the barrel (there's a cutout in the inner barrel for it to go through).

The rubber is pushed down from the top (12 o'clock position). As a bb pushes against the hopup rubber, air pressure eventually pushes/sqeezes it past the hopup rubber and it picks up backspin. As it travels, that backspin helps keep the bb flying "level"...up to a point.

To adjust your hopup, you need a good bit of space (100ft)...30 ft in your basement won't really be enough...out in the local park is not a good idea.

Start with the hopup off (turned CCW). Hold your rifle level. Take a couple of shots. Your BB probably won't go very far before in just drops. Turn on the hopup...as it takes effect, your shots will go further and further. If you put on too much hopup...you'll notice your BBs go out and then arc upwards (like a jet taking off from a runway). That's too much. Your shot should go out "flat and level" as far as it can without arcing up.

Different hopup rubbers will have different hardnesses...some are soft (and impart more backspin) others are hard (last longer but don't put on as much spin).

Only use good bbs. BBBastard, Madbull, KSC, Excel, etc....don't use the crappy Canadian Tire BBs.

Have fun,

Tys

Oh right...forgot the pistol part. Exact same effect...except you use the "key" to turn the adjustment in the barrel CW or CCW. As it turns, it pushes the hopup rubber down or let's it up. If you can get your barrel out of your pistol...you should be able to look down it as you fiddle with the adjustment and see what it's doing in the barrel. With a GBB pistol...you typically need some hopup or else cycling the slide will just knock/croquet the bb out of the chamber before you shoot...it just dribbles out the end.

[Jbone 11 11]

Wow, super informative! Thanks!! Much appreciated.

J

[kalnaren]

I'd like to add, the importance of properly adjusting your hop-up can't be overstated. Using heavy BB's with proper hop-up settngs will do wonders for your effective range. Also, the hop-up isn't static. You'll likely need to readjust it every time you play, depending on atmospheric conditions and the like.

One last thing: don't forget to dial it off before you clean your barrel.

[Crunchmeister]

And one more thing to add to what kalnaren said - you'll also have to readjust the hopup if you change BB weights. Heavier BBs will require a more agressive hopup setting to get the same effect.

[Jbone 11 11]

"One last thing: don't forget to dial it off before you clean your barrel."

Why exactly is that? Do stand a chance of messing up the Hop up if you dont?

Again... thanks everyone for the info! Really helping me look like I know what Im doing over here ; )

[yuhaoyang]

Turn the hop-up down to minimum when you finish plinking or get home from a game, it will prevent streching of the hop-up rubber, and if you get grease on yyour hop-up during cleaning, it will be useless for a few hundred rounds, also, rubbing your hop-up rubber with a cleaning tool can cause excessive wear.

[kalnaren]

Originally Posted by Jbone 11 11

"One last thing: don't forget to dial it off before you clean your barrel."

Why exactly is that? Do stand a chance of messing up the Hop up if you dont?

Again... thanks everyone for the info! Really helping me look like I know what Im doing over here ; )

Because the hop-up rubber protrudes into the barrel, so when you jam a cleaning rod down it, you don't want to rip the hop-up rubber.