KWA M4 Shooting a bit off
 

Hey guys, I'm not convinced my KWA M4 is shooting as it should. It used to shoot great, and it hasn't been the same since I installed my tightbore. I went back to the stock barrel and it doesn't fix it. So I have my tightbore in there now, and it's acceptable. but I feel it should be much more accurate.

I'm using my TM P90 (stock except for metal bushings) as a reference for the accuracy.

The P90 is VERY accurate at roughly 40 feet with a grouping Less than 1 inch.

The M4 with a Madbull v2 6.03mm tightbore groups at closer to 1.5 inches.

At 100 feet the P90 groups at about 5 inches, while the M4 can hardly hit a pie plate. I know something has to be wrong here since my m4's barrel is around double the length and much tighter.

The P90 shoots 260-280 FPS and has no consistency mods.

The M4 shoots around 390 FPS and has bearing spring guide and piston head (Stock). I also installed a Firefly hopup rubber, the stock KWA rubber didn't fit my upgrade barrel. I was using a CA rubber before the Firefly, but I was told CA hop rubbers suck, so I nixed it.

If there is any other info u need let me know and I'll provide it. I'd like to get this gun shooting better than my P90, at least at 100+ feet.

I heard that pass 360fps, bb's start to have strange behaviour...

:cool:

Yeah I was thinking about that, deviation can increase from high velocity. Although, my other guns were right around 400FPS and were fine. it's just really weird.

Maybe your barrel wobbles.... ( but for that, does your gun shoot at the same place always, or your bbs fly at different direction each shot?)

They seem to favor straying right, but I get flyers in all directions.

try heavier bb's if your not already.

Once you remove a hopup and switch barrels it is never the same.

Also a swab down the barrel and some light oil will do wonders.

I cleaned my new AK barrel after a few games and now it is a laser.

I haven't gamed it yet, should I just lube it up and take it through a few hundred rounds before I get upset about this? Maybe it'll settle in?

ya maybe your barrel wobbles then.... Each time the nozzle & cylinder "slams"on the hopup unit.... Check it you have the little spring on top of the hopup unit...if you know what I mean.... Because maybe it fell when you changed the barrels....

I know the one you mean, it's in there, the barrel and hopup move very freely in and out of the barrel. but it doesn't have any sideways slop. Iv'e also tried a TM hopup chamber to be sure, and it does the same thing.

How many rounds through that hop-up rubber? And what hardness is it? I find rubbers always take at least 2-300 round before they are worn-in and consistant.
Cheers,
Grant

I believe its a firefly medium, the rubber itself has fired a few thousand rounds, but only maybe 50-60 with the new barrel. Maybe I should just lube it and shoot the crap out of the gun for a bit.

have you cleaned your inner barrel and hop up rubber in cold soapy water and let it air dry, check the condition of your hop up bucking.....

best of luck

Did you get any oil on your rubber?

Firefly rubbers need to be broken in. Fire a good 500 shots through it.

Thanks Amos, the rubber is bone dry at the moment. I haven't lubed it since I got it back together. I'll put a couple drops of oil in the bb inlet and run a hicap through it.