Davegolf
Members
- Sep 22, 2009
- 2,103
- 850
If you have an ICS SA80 and you get double feeds (1 shot, 2 bb's leave barrel) this is what i have found after much messing about to fix the problem.
The problem is in the hop unit itself, the barrel does not penetrate far enough into the hop unit, meaning there is room for more than one bb to be 'chambered' and consequently fired during one shooting cycle.
I fixed this by removing the barrel, hup bucking and nub from the hop unit
Measuring the depth of the bore that the barrel goes into from the 'exit' down to the shoulder the hop rubber stops against.
Then using a 9.7mm drill carfully tickle the plastic until you have increased the measured depth by 0.5mm
When you took the barrel out of the hop unit you probably noticed the small 2 piece clamp which holds the barrel into the hop unit with 2 small phillips screws.
This needs to also locate 0.5mm further into the hop unit.
You can either file the clamp ears down 0.5mm or file the locating recess 0.5mm deeper, i did the latter.
You will also need 2 small shims or washers to place on the unfiled side of the 2 piece clamp so that when you screw it back together it screws up tight and makes sure the barrel moves into the hop more.
Id previously tried all sorts of things to fix this problem of which none of them cured the problem;
Airfet MoSfet
Systema hop bucking
Gaurder hop bucking
other mags
lubricating things
dergreasing things
I refitted the stock bucking and nub, removed the Mosfet and used standard mags again, just as a test seeing as id made so many changes, and its spot on.
Accuracy is up quite substantially now, i assume this is down to tighter clearances and more consistent air pressure, gun rocks now
If people are interested il take some pics cos that sounded confusing to me lol!
The problem is in the hop unit itself, the barrel does not penetrate far enough into the hop unit, meaning there is room for more than one bb to be 'chambered' and consequently fired during one shooting cycle.
I fixed this by removing the barrel, hup bucking and nub from the hop unit
Measuring the depth of the bore that the barrel goes into from the 'exit' down to the shoulder the hop rubber stops against.
Then using a 9.7mm drill carfully tickle the plastic until you have increased the measured depth by 0.5mm
When you took the barrel out of the hop unit you probably noticed the small 2 piece clamp which holds the barrel into the hop unit with 2 small phillips screws.
This needs to also locate 0.5mm further into the hop unit.
You can either file the clamp ears down 0.5mm or file the locating recess 0.5mm deeper, i did the latter.
You will also need 2 small shims or washers to place on the unfiled side of the 2 piece clamp so that when you screw it back together it screws up tight and makes sure the barrel moves into the hop more.
Id previously tried all sorts of things to fix this problem of which none of them cured the problem;
Airfet MoSfet
Systema hop bucking
Gaurder hop bucking
other mags
lubricating things
dergreasing things
I refitted the stock bucking and nub, removed the Mosfet and used standard mags again, just as a test seeing as id made so many changes, and its spot on.
Accuracy is up quite substantially now, i assume this is down to tighter clearances and more consistent air pressure, gun rocks now
If people are interested il take some pics cos that sounded confusing to me lol!