Erratic accuracy

[Fitch]

Wonder if a kind soul could help.

I built up my first M4 the other day based on G&P internals. The gearbox and main body were essentially left intact so all I had to do was swap barrels, reposition wires and swap out hopup and inner barrels.

All worked dandy until I fired it a few times - each shot is great but seems erratic - accuracy is awful with several shots spraying all over the place Compared with my other M4s this is a bit of a disappointment. Any idea what it could be? The guns using a 6.03 inner barrel (I did shorten it and ensured that there isnt any burring)

Hopup seems very sensitive - BBS can either shoot and drop real quick (no hopup) or when wound on full, they spin and rocket upwards 10 metres from being shot. Seems normal hence why I wind it about halfway to get decentish range.

Not sure if its the bucking/hopup itself thats creating the lack of consitent accuracy.

Any ideas?

[guard-sniper87]

Re: Erratic accuracy

What barrel have you got inside mate

Also what hop unit and rubber have you got

Also clean the new barrel and try a better grade of .2 ammo

[Fizzy]

Re: Erratic accuracy

Could be hop, could be that you did leave a burr on the barrel. Have you still got your old barrel to try it?

[Fitch]

Re: Erratic accuracy

Thats what I was thinking - burr on the end of the barrel which produces a "flick"

The barrel is a Prometheus 6.03 (cut) and a simple G&P metal hopup unit with G&P bucking etc

Has to be a burr I reckon.

[gijohn2]

Re: Erratic accuracy

My friend had a Metal G&P hop up unit and it made his gun double feed and 3/5 BB's would drop short so i said swap back to the olg G&G one and it all worked fine =/

[richardy]

Re: Erratic accuracy

you need to chrono it to rule out and fps issue.

Reseat the hop unit, rubber and barrel and clean the barrel for starters

[danhc]

Re: Erratic accuracy

is your hop up rubber ripped by any chance or damaged where it makes contact with the bb? had this problem a while back with a m468 and a m249 and both where due to the rubber being ripped

[North West Outpost]

Re: Erratic accuracy

As others have said really, I would take the barrel and hop out and apart. Clean the barrel and replace the rubbers in the hop and put it all back together again.

If the hop rubber is new they can take a while to bed in and settle down. But they shouldn't be shooting most shots all over the place, but one or two will go off target for a while.

[seansamurai1]

Re: Erratic accuracy

I have had the same issue with a G&G for a long time now (since I first got it) new hop rubbers, new hop units, a new barrel, everything, however I have found a fair bit of movement on the hop unit, a good mm of travel, whereas my other armalites dont have this issue, yours might be the same, basically an air leak on certain shots.