G&P M4A1, BBs curve left

[Affliction]

I've noticed this problem since I've gotten my G&P M4A1--When I shoot, the BB goes straight for about a foot, then veers off to the left (1-2 ft off target from 10 yards)

Any idea what may cause this? How would I fix it?

Thanks
-VM

[thePiRaTE!!]

I'm not too techy, but have sorted a few weird issues out on my M4's lately, so I'll give you something to chew on until a real doctor is in the house.

Its something in your barrel, either the hop-up or dirt. First, try rolling your hop-up completely off and - using the cleaning rod and a long cut strip of paper towel sprayed with silicone oil - spin-clean your inner barrel. Without re-engaging the hop-up, try firing again. You should be good for 10m with no hop-up at all so if its either gritty barrel or bung hop-up causing the problem, it shouldn't be anymore. You can rule these out anyways.

[Affliction]

My M4 didn't come with a cleaning rod--What else could I use instead?

Thanks.
-VM

[thePiRaTE!!]

For such a simple thing, a cleaning rod might be tricky to properly replace. I'd suggest sitting tight until you can get to your nearest arms dealer and coax one off him.

Certainly if you haven't cleaned your barrel yet, you are in for a dirty surprise.

[Prowler]

check your hopup rubber and its other parts, it might be because of that. G&P hopups generally get replaced first

[Dracheous]

a string with a small weight on one end and a towel on the other to pull through? How much harder does it get to replace?


Do what I did, check to see if your innerbarrel can move inside the one peice barrel assembly. If yours does to get some tape or something to stiffen it up a tad... worked for me...

[thePiRaTE!!]

Originally Posted by Dracheous

a string with a small weight on one end and a towel on the other to pull through? How much harder does it get to replace?

Give that idea a second though, its pretty sensitive inside the inner barrel. Even if you used fishing line to prevent fibers from the sting, a little nick from a weight could set you back. Even if you were careful, the whole up-down-spin action is pretty key to 'scrubbing' off oily mess as well, and would be tricky to do without a rigid tool, like a cleaning rod.

Good-luck whatever road you choose, but I'd advise patience. The tool invented to handle it properly should cost you all of nothing anyways.

Originally Posted by Dracheous

Do what I did, check to see if your innerbarrel can move inside the one peice barrel assembly. If yours does to get some tape or something to stiffen it up a tad... worked for me...

Definitely another thing to check, yep.

[Kampfer]

G&P's M4 are know to shoot sideways out of the box.
It's not the dirt in the hopup or in the barrel. (it might be in your case since your's start curving 2 feet out of the barrel.)

Take these one setp at a time.
- replace the hop-up sleve with a TM / guarder/ systema sleve. (becareful not to stretch the sleve or lose the hopup nub)

if it doesn't fix the problem right away then
- replace the hopup unit with a systema hopup unit.
usually by this point the problem is fixed until one of the following internals break on you, trigger post, tapplet plate, trigger safety latch.

problem still?
change the nozzle to a plastic one made by Guarder/systema/TM/Prometheus
change the inner barrel to stock TM or tightbore. (very rare that you'll have to get to this point.

[Dracheous]

Pirate, all you need to do to create a weight in a peice of string is tie a good tight knott in the end of it. I didn't say bailing wire, or strapping here, I'm talking your average soft string that comes nice and clean from any fabric retailer. This works perfect for any of my rifled barrels, best on my shot guns. I'm never pulling any hard materials through those barrels its always a soft material that is never bunched up. Best to let it stay long and just get more surface area rather than pressure on a single wipe.

All of this done to the inner barrel while its out of the gun as its not a hard thing to remove.