Interesting discovery regarding air leaks
 

This isn't for everyone, but the info is interesting for all airsofters/gun techs.

Often times this year when shooting my CA M24 I've found my shots had veered off to the right after about 150-180ft, making things pretty frustrating. Obviously I attributed this to wind, as anyone who watches the flight of their BBs travelling own range.

Just within the past hour I've been toying around with my M24, sorting out what mods and tuning to do over the winter for next season's games. I have a worn out Laylax 150SP spring in it, it's shooting right now (after two years of use) in the ballpark of 470-480fps with 0.20g BBs. This really has nothing to do with my "discovery" however.

I decided to check for sealing between my nozzle and the hop up unit/rubber, I fired up my Streamlight Scorpion, held it in my magwell, and with an empty chamber (and eye protection for those wondering) saw a decent amount of light shining through on the right side of my chamber. I loaded a BB in to check again, same thing, light passing the right side of the BB.

While this is an airleak, here's the interesting part. I sorted out what effect a leak on one side might have on a BB. It's the air leaking on the right side passing the BB and the higher pressure on the left side of the BB that is causing my rounds to have that slight hook to the right after a certian distance.

In my case, I have to adjust the two screws on either side of the hop up unit (the screws secure........ and now I find out center........ the inner barrel) to get rid of that imbalance of leakage/pressure.

Figured I'd post this for the sake of interest, if you find your BBs hook at a certain distance repeatedly, check your inner barrel to make sure it's properly centered, hop up rubber is instact, clip that holds the inner barrel to the hop up unit is intact with no cracks (this causes large fps droppage), etc.

Thanks for sharing, Stalker :)
I suspect a similar problem in Darkalman's FN FAL, but around the whole nozzle and not just one side....We'll try a different nozzle.

Good find. Thanks!

This is likely a M24-only solution and issue. Most AEG hop-ups do not have any adjustment or play in the inner barrel as it is, and they don't offer any options with the stock nozzle. It is what it is.

Airseal problems with an AEG usually manifest themselves in grossly low velocity, rather that a hooked shot at 180 feet, unless you are a twit when installing your rubber and bucking.

Man, am I glad I never have to deal with farting around with AEG (or springer) nozzles and hop-ups ever again. Too many variables to guarantee any kind of durabilty or consistancy.

Wow, do you foam at the mouth waiting for opportunities to praise the PTW over all else?


Hey Stalker, there should also be a pair of O-rings in the hop up units to help with that. They are a bitch to install too, I remember giving up on the second one as it was half inch down the unit and was difficult to get tools in there. One thing I've been wondering lately Stalker, is that on a "lesser" aeg hop up, you usually only have the one brass ring to centre up the inner barrel, I wonder if two would improve it? IE, one on either side of the C-clip? Also I remember in my bushmaster G&P hop up, that the brass ring would slide out easily, so I applied scotch tap to the ring and it snugged up good.

I don't recall typing anything above that said PTW. You assume too much.

I think it's time you be quiet and let the adults speak. How quickly you forget what you typed only 2 weeks ago.

So what? You're playing with a McDonald's straw now?

Besides, the PTW hop up is inferior to some TM hop up builds.

If you don't have access to an indoor range, try turning off your hop up and fire your rifle inverted and right side up. If you can reverse a horizontal veer by flipping the gun then there is something that is breech or barrel related causing your problem.

No. MacDonalds is for kids. Wendy's is for adults.

Perhaps. But there are no aftermarket parts for it. There are no mods to do to it that are really any better that what the design allows. There's no trying to make "X" part fit. It is what it is. Doff sells his version of an aftermarket cage, and it's better than older Gen 1-3, but debatable in MAX. There is no tinkering, unless your a sucker for teardown and re-assembly.

Thanks for the tip Stalker. Just checked my APS, no light shining through whatsoever.

To be absolutely sure I tried it four times. Piston pulled back and out of the way, no BB (full light for a standard); Piston closed (cylinder head in hop-up unit), no BB; Piston pulled back, BB loaded; Piston closed, BB loaded (and bold up, safety on, and trigger clear). Had goggles on for safety.

First test I had full light (of course), but all the others it was pitch black.

I know my problem/fix is narrowed down to the the adjustable hop up unit for the CA M24 and the APS2, but I thought the info regarding leaking might be of interest as a possible way to diagnose some symptoms as listed above, but I also added in the 'use a light to check the rubber' trick for AEG troubleshooting. It's helped me more than once determine why a few AEGs have had a drop in fps suddenly or over time.

And Drach, I know about those rings in the unit, but my unit is well worn and it was worn when I got the gun itself, hence my looking to buy your spare when you get your M24.

Dracheous = Fail

Hell, I don't own or have even played with an APS or M24.. but I found the post interesting and I think I have learned something. Who gives a fuck if it's only for those 2 guns?

I love how people bitch that nobody wants to inform themselves, and yet when a post like this is made people bitch that it's proprietary.

I found it interesting. I never thought of using the light to check the hop-up. Thanks for the post Stalker.

Lol.

Ok, I've posted this before in previous posts, it's a trick for all guns to determine if your hop up/inner barrel is straight. Load with some decent 0.12g BBs, full hop up setting, hold gun as level as you can and shoot. The BBs will grossly overhop at a very short distance and you can see if they go straight up or cant to one side or the other.

:D

LoL. My barrel is 200mm long lol They go all over the place.

Cool! Now I have a use for those .12g BBs sitting in my basement! :)

I regularly load the first dozen or two (depending on low cap or mid cap) with red 0.12g BBs to act as indicators for low ammo. See red, hear the change in sound, reload. Prevents dry firing on an empty mag.

I've heard that you do that one before. For my gun, the sound of it dry firing is very distinct, so I only fire 1-3 dry cycles. I don't think it really hurts it too much.

All guns sound distinct when dry firing (sound difference between regular BBs and 0.12g BBs is a bit sharper pitch with the .12g), but for guns with a V2 mechbox, dry firing can kill it, and even a couple cycles each mag add up to a dozen or more cycles per game day, add on dry firing to set the piston forward at the end of the day, to test firing if any work has been done in the mechbox......... all adds up.

Besides, it looks a lot cooler to do a tactical reload than to run out of ammo to the point of being empty. Best thing? I've actually gotten some 0.12g kills this way. How many guys have called hit when you've dry fired at them? ;) Lol

Yeah rushing some poor bastard because you know hes dry firing on a mag and catching them in mid reload will make them shit themselves and the look on their faces is totally priceless...

Well, I'm sure Classic Army would surrender to a gun dry firing, simply because the noise is travelling at the speed of sound and is over the field fps limit.

On my gun when its 'dry' it stops shooting :p

The barrel in my GBB is 110mm and its dead accurate :p
Maybe you need a tightbore/hopup rubber upgrade?

Stop wanking your PTW, wanker.

He needs to learn how to shoot properly first. ;)

about the same thing. but I only load 5 .12 clear green BBs... (They are ugly, better send them in the washer, 200-300 in a cloth bag to remove the mold lines a bit...

They somehow shine really bright green when indoors, and outdoors it's not that bad...

Almost only on semi... so 5 is plenty enought...

i would assume stalker puts around a dozen or so .12g in rather than 5 because he is shooting in full auto mode with a high ROF.

That is definately an interesting find stalker. I have the exact same problem on my CAm24 and have had it since day one. Ill have to adjust it all and let you know how it works out.

Actually it reduces the number of rounds in my mags. Brings my 90rd midcaps down to Armalite low cap levels. Helps me carry a bunch of mags and still stay within the 300rd limit some fields have. Also, I can reload my mags mid day and not have to keep topping up the indicator BBs.

One thing to keep in mind, any gun with a Guarder clear hop up rubber can't be checked for leaks with a flashlight............. for obvious reasons. Lol