Feeding Issue---Opinion

[Trev140_0]

I figured this might be a good post to toss up to get the opinion of others.

The "my gun is feeding crap" seems to be a recurring theme.

This can be caused by bb brand, mags with poor or no spring compression or when this post is about.

When upgrades or changes are done outside stock parts, different tolerance and manufacturers are introduced. For example going from one M4 nozzle to another or even hop up housing can change position of stock parts to cause other performance issues.

As many have said here before, its best to change one thing at a time to be certain the new part introduced is not causing issues.

With that said I am looking for confirmation that the picture below is what I think it is.

M4 G&G platform.

You are looking at a CNC hop up (Prowin) housing in the feed tube. This is CNC Machined. I will get back to that later.

The nozzle is an upgrade as well. Don't know the brand. But orange also an upgrade as well. See photo to the right the ORANGE nozzle which is supposed to be fully recessed partially in the hop up chamber.

imagejpeg_2.jpg

As mentioned, the reason why I made a point of the hop up housing being CNC machined, is because unlike the typical CAST hop up, the CNC is supposed to be more repeatable in the manufacturing process. With that said, it is also less forgiving. I have not measured the bore opening in the feed tube, but my gut is this is slightly oversized of the 6MM. Perhaps 6.1mm. Will see if I can get gage pins to confirm what this is machined to.

The gun complaint was:

• Some mags worked better
• Worked better beginning of the day
• Some BBs feed better. (this one is me as I used .28 G elite on these and the gun was gamed with .3 this weekend, other brand and has issues)

The 3 above are all not issues, but things that can amplify the clearance issue this gun has.

So two things.

1) Am I sure this is the issue? My gut is yes. Hope to hear others confirm
2) Some suggest to file the nozzle but I want to put the hop up forward. Essentially put a spacer in between the hop up housing and the GB. I know this will put the hop up housing in a slightly forward position my a mm or so, but think this will not cause any alignment issue on the mags.


Opinion please.

[lurkingknight]

if you can flip the gun upsidedown and gravity feed the tube.. put 3 or 4 in there and put light pressure in the tube so they don't fly out when you shoot... if it feeds find, the BBs are traveling up the feed tube just fine.

IF you have to force the BBs in, then you have an issue with the nozzle being too long or
the feed tube in the wrong position.

If everything drops in with minimal pressure then look at the BBs and the mags.

Load the mags, put it in a bag and flip the retainer.. if they spray out like a fountain, there's good pressure in the mag... If they sort of bubble out, there may not be enough force to push the BBs into the chamber fast enough.

Why you're experiencing some mags or some bbs causing the issue is that some bbs have better slickness to their polish and they slide against each other better than others. Secondly, the BB follower in the mag is sort of pushing the BBs off at odd angles, not directly along the chute.

If you can confirm it's a mag issue you can modify the follower to cup the BBs better and stagger the first 2 so they stack nicer and push upwards rather than be pushed outwards into the wall of the BB channel.

[Trev140_0]

Originally Posted by lurkingknight

if you can flip the gun upsidedown and gravity feed the tube.. put 3 or 4 in there and put light pressure in the tube so they don't fly out when you shoot... if it feeds find, the BBs are traveling up the feed tube just fine.

IF you have to force the BBs in, then you have an issue with the nozzle being too long or
the feed tube in the wrong position.

If everything drops in with minimal pressure then look at the BBs and the mags.

Load the mags, put it in a bag and flip the retainer.. if they spray out like a fountain, there's good pressure in the mag... If they sort of bubble out, there may not be enough force to push the BBs into the chamber fast enough.

Why you're experiencing some mags or some bbs causing the issue is that some bbs have better slickness to their polish and they slide against each other better than others. Secondly, the BB follower in the mag is sort of pushing the BBs off at odd angles, not directly along the chute.

If you can confirm it's a mag issue you can modify the follower to cup the BBs better and stagger the first 2 so they stack nicer and push upwards rather than be pushed outwards into the wall of the BB channel.

Awesome post and agree with you totally. I don't have my hands on the gun, but speaking with the guy who has it, he tried to drop bbs in and they do take force to get them in. While he reported "not too much", to me there needs to be ZERO.

Reason is 2 fold.

1) The polish on the bb is enough to make a difference in a point where contact is made
2) If even one of the bbs in the 100-150 in the mag are "top limit" in size you will have a jam.

Bottom line there needs to be CLEARANCE not INTERFERANCE that needs to be overcome by the force of the spring of the mag.

Will report more back after more messing around.