More problems with my dpms M4.

Janz99 · May 10th, 2009, 22:50

So we went out to play a couple rounds today with a few friends. I just did a series of upgrades to the gun, but it seems that the gun is shooting poorer then it was before the upgrades.

The BB's seem to almost LOB. It has plenty of bark behind the BB's and they seem to hurt just as buch as before, but they seem to arc downward instead of going straight. If tried adjusting the hob up, but that actually seemed to make it worse. Any ideas?

Thanks
Ryan

ThunderCactus · May 10th, 2009, 22:56

did you chrono the gun?

Crunchmeister · May 10th, 2009, 22:59

Try removing and reinstalling the hopup rubber. It might not be seated properly when you installed it.

Janz99 · May 10th, 2009, 23:44

Thanks for the tips guys, i did try to re-install the hop up rubber and it didnt make a differance. I actually had to put my old hop up rubber back in, because the gaurder clear hop up rubber i had was causing the bb's to jam up inside the barrel for some reason.

I didnt crono the gun yet. I dont know anyone with a tester or anywhere that would let you bring the gun down to test it.

Anything else that i could try or test?

Thanks
Ryan

Mitchell12 · May 10th, 2009, 23:53

Look up the "poor man's Chrono" It's a relatively consistent way of vaguely quantifying your upgrades.

Crunchmeister · May 10th, 2009, 23:57

Poor man's chrony shouldn't be used to guess velocities. I've tried to compare my chrony results from my guns with can shots, and it's too inconsistent to be able to come up with even ballpark figures.

Styrak · May 11th, 2009, 01:03

Quote:

Originally Posted by Mitchell12

Look up the "poor man's Chrono" It's a relatively consistent way of vaguely quantifying your upgrades.

No, it's really not that accurate.

Janz99 · May 11th, 2009, 02:35

Logicly, what could be causeing the downward arc of the BB's? The hop up is suppose to cause the opposite effect, the more you adjust it the more back spin thats applied and should go upward. More hopeup actually causes the oposite on my gun right now.

Moving back in the gun, we have the air tip nozzle, i put a modify nozzle on the gun, but ive inspected it, and it seems fine. Other then that, there is nothing that that comes in contact with the BB and could cause this delema.

I thought maybe it was it was the barrel itself, so i put the stock barrel on, and i have the same problem. So unless my outer barrel is somehow effecting how the inner barrel sits and for some reason causeing the downward arc??

Im kind of at a loss as to what i should be looking at. If anyone has any other ideas, im all ears

Thanks
Ryan

Styrak · May 11th, 2009, 02:39

Stupid question, but you put an M4 nozzle in, right?

Janz99 · May 11th, 2009, 02:54

Yes, i actually just double checked my order form to make sure. Its a modify nozzle for an m4. If the nozzle wasnt the proper one, it would cause a bad seal on the hopup unit?

One thing i do consider odd, was that i dont remeber seeing any sort of o-ring in or on the nozzle that i recieved. In the description of the modify nozzles it says "Features an internal o-ring for improved air seal". I dont remeber seeing any sort of o-ring. Would i have had to install the o-ring in the nozzle, or would it have already been installed from the factory?

yuhaoyang · May 11th, 2009, 03:05

Should have been in already, I have the same one your talking about, if it isn't there, that's your problem. Contact your supplier, ask for a new one.

Styrak · May 11th, 2009, 03:22

Still, if that o-ring wasn't there it wouldn't cause a big airseal problem like he [might be] describing.

yuhaoyang · May 11th, 2009, 04:55

I couldn't really undrestand what he was describing, but that's just my lack of english skills. That nozzle relies mainly on its o-ring to seal doesn't it? The one on mine is quite prominant.

Janz99 · May 11th, 2009, 15:20

Ive even tried swapping between the factory barrel and my madbull tight bore with no luck. Im really at a loss here

Could it be an issue with the stock spring having to be put back in place? The small aluminum block where the spring hook goes into was omitted because the piston head has a bearing on it. So i ommited that piece and trimmed the hook off the factory spring.

I tried the poor mans chrono, and sometimes it will go right through the can, sometimes only through the first half.

Ryan

Styrak · May 11th, 2009, 18:07

Quote:

Originally Posted by yuhaoyang

I couldn't really undrestand what he was describing, but that's just my lack of english skills. That nozzle relies mainly on its o-ring to seal doesn't it? The one on mine is quite prominant.

No, some nozzles don't have an o-ring at all. But it definitely helps the airseal in the upgraded ones.

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May 10th, 2009, 22:50	#1
Janz99 Trader rating Join Date: Apr 2009 Location: Winnipeg	More problems with my dpms M4. So we went out to play a couple rounds today with a few friends. I just did a series of upgrades to the gun, but it seems that the gun is shooting poorer then it was before the upgrades. The BB's seem to almost LOB. It has plenty of bark behind the BB's and they seem to hurt just as buch as before, but they seem to arc downward instead of going straight. If tried adjusting the hob up, but that actually seemed to make it worse. Any ideas? Thanks Ryan

May 10th, 2009, 22:59	#3
Crunchmeister Trader rating Join Date: Nov 2007 Location: In your bedroom going though your underwear drawer	Try removing and reinstalling the hopup rubber. It might not be seated properly when you installed it. __________________

May 10th, 2009, 23:57	#6
Crunchmeister Trader rating Join Date: Nov 2007 Location: In your bedroom going though your underwear drawer	Poor man's chrony shouldn't be used to guess velocities. I've tried to compare my chrony results from my guns with can shots, and it's too inconsistent to be able to come up with even ballpark figures. __________________

May 10th, 2009, 22:56	#2
ThunderCactus Not Eye Safe, Pretty Boy Maximus on the field take his picture! Trader rating Join Date: Feb 2007	did you chrono the gun?

May 10th, 2009, 23:44	#4
Janz99 Trader rating Join Date: Apr 2009 Location: Winnipeg	Thanks for the tips guys, i did try to re-install the hop up rubber and it didnt make a differance. I actually had to put my old hop up rubber back in, because the gaurder clear hop up rubber i had was causing the bb's to jam up inside the barrel for some reason. I didnt crono the gun yet. I dont know anyone with a tester or anywhere that would let you bring the gun down to test it. Anything else that i could try or test? Thanks Ryan

May 11th, 2009, 02:35	#8
Janz99 Trader rating Join Date: Apr 2009 Location: Winnipeg	Logicly, what could be causeing the downward arc of the BB's? The hop up is suppose to cause the opposite effect, the more you adjust it the more back spin thats applied and should go upward. More hopeup actually causes the oposite on my gun right now. Moving back in the gun, we have the air tip nozzle, i put a modify nozzle on the gun, but ive inspected it, and it seems fine. Other then that, there is nothing that that comes in contact with the BB and could cause this delema. I thought maybe it was it was the barrel itself, so i put the stock barrel on, and i have the same problem. So unless my outer barrel is somehow effecting how the inner barrel sits and for some reason causeing the downward arc?? Im kind of at a loss as to what i should be looking at. If anyone has any other ideas, im all ears Thanks Ryan

May 11th, 2009, 02:39	#9
Styrak Trader rating Join Date: Jan 2007 Location: Saskatoon, SK	Stupid question, but you put an M4 nozzle in, right? __________________ Airsoft Sales and Repair/Upgrade Services

May 11th, 2009, 02:54	#10
Janz99 Trader rating Join Date: Apr 2009 Location: Winnipeg	Yes, i actually just double checked my order form to make sure. Its a modify nozzle for an m4. If the nozzle wasnt the proper one, it would cause a bad seal on the hopup unit? One thing i do consider odd, was that i dont remeber seeing any sort of o-ring in or on the nozzle that i recieved. In the description of the modify nozzles it says "Features an internal o-ring for improved air seal". I dont remeber seeing any sort of o-ring. Would i have had to install the o-ring in the nozzle, or would it have already been installed from the factory? Last edited by Janz99; May 11th, 2009 at 03:01..

May 11th, 2009, 03:22	#12
Styrak Trader rating Join Date: Jan 2007 Location: Saskatoon, SK	Still, if that o-ring wasn't there it wouldn't cause a big airseal problem like he [might be] describing. __________________ Airsoft Sales and Repair/Upgrade Services

May 11th, 2009, 15:20	#14
Janz99 Trader rating Join Date: Apr 2009 Location: Winnipeg	Ive even tried swapping between the factory barrel and my madbull tight bore with no luck. Im really at a loss here Could it be an issue with the stock spring having to be put back in place? The small aluminum block where the spring hook goes into was omitted because the piston head has a bearing on it. So i ommited that piece and trimmed the hook off the factory spring. I tried the poor mans chrono, and sometimes it will go right through the can, sometimes only through the first half. Ryan Last edited by Janz99; May 11th, 2009 at 15:25..

More problems with my dpms M4.

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