I apologize in advance if some one has posted this already but I could not find anything like this anywhere so I said to hell with it.
Ok, so I was really bored today and I thought to my self as I was cleaning the gun, how can I make this hop-up better? So I came to this conclusion, even though there are 2 hop-up arms it still acts as if it is only one. Here is a horrible drawing done on paint....
Ok, this is the hop-up with the stock nubbin( in red because clear doesn't show up as easily

), as you can see there are 2 arms.
Now what would it look like in the gun with it pushing down on the BB, and say your bars are not set at the same level, due to a mean curve you are trying to fix.
As you can see, it does not sit with the hop-up arms there is a small gap from one level to the other. Now, you may be saying why would this matter its only 1/32 of a inch (made that up, I have know idea what the gap is :

). Well yeah at 100 ft sure it will fix the curve what about at 250 ft, or 300 ft. That small gap may be the difference between a 18 in grouping and a 9 in grouping at 150 ft( the distance used for this test).
So I came up with this DIY mod, and here is a basic drawing of it
Basically I cut the hop-up nub in half, witch in theory would eliminate the gap. But why stop there, when you can experiment with different type's of nubs that would use the same system (This is a endless amount).
So here begins the DIY mod, first here are the items you need, one Hop-up
Super glue and tweezers
and a pair of dikes ( wire cutters) , or even better a exact-o knife
Ok, so the first thing you want to do is have a stable platform to start. The first thing I did after removing the Hop-up was to take one arm and super glue the nub to the one are making extra sure that it was straight. I can not stress how important this is, it is the make or break of this. Use the tweezers to prevent your hands being glued to your $60 hop-up.
Next, I removed the arms completely to get the nub sized up on both sides. Now here was one of the more steady handed things to be done. You want to that your knife and as carefully as you can cut it exactly down the middle. Once you do that you will need the tweezers once again to glue this piece in place.
When you do that you want to let this set, and I don't mean for 30 min's ether. You want to let it set for minimum 8 hours, so over night is best. Now I can here people saying "But its super glue it sets in 10 min's." Yes, it does, but it is not set, and when bonding a little thing of rubber to a small metal bar you want to let it set.
Also do not keep them together they will glue together. This is how I keep mine while I let them set.
I will post test results on Monday because I don't have the time to do it tomorrow, because I am going rock climbing. Also in the test I will post the grouping sizes, and how well it fix's bad curves at a distance. If there is a particular range you would like to see post it or pm me and I will try to get to it on Monday. So far I will do 50, 100, and 150 feet, if I can get it to go farther then I will see maybe 200.
Also a note if you find a grammar error or spelling error PM me, do not post it on this tread.
UPDATED Jan 16, 3:30 pm pst
Test Results
Test constancy's
-20 shots with a tuned hop-up (in 5 shot batches, and measurements done in circle diameter)
50 Feet
Before
First batch- 8 in diameter (about 5mph to 15mph gusts)
Second batch- 9 in diameter (same wind conditions)
Third batch- 9 1/2 in diameter (" " " ")
Fourth batch- 7 3/4 diameter (" " " ")
Average circumference of 26.95 in^3
After
First batch- 6 in diameter (about 5mph to 10mph gusts)
Second batch- 5 1/2 in diameter (same wind conditions)
Third batch- 7 1/2 in diameter (" " " ")
Fourth batch- 7 1/4 diameter (" " " ")
Average circumference of 20.57 in^3
Conclusion for 50 feet there was a decrease of 6.36 in^3, what this means is that the accuracy went from a soccer ball to about a soft ball.
If wind is better tomorrow I will do 100 and 150. I took pictures but they do not do any justice to the math.
So I went out after I got back from work and was able to get the 100 ft test in while there was still light. Here are the results.
100 Feet
Before
First batch- 15 in diameter (about 5mph or so)
Second batch- 14 1/3 in diameter (same wind conditions)
Third batch- 16 1/2 in diameter (" " " ")
Fourth batch- 16 3/8 diameter (" " " ")
Average circumference of 48.83 in^3
After
First batch- 12 2/5 in diameter (about 5mph or so)
Second batch- 14 1/2 in diameter (same wind conditions)
Third batch- 13 3/8 in diameter (" " " ")
Fourth batch- 12 1/4 diameter (" " " ")
Average circumference of 41.21 in^3
conclusion, there was a difference of 7.62 in^3, as you can see there is not much of a difference. As for 150 ft I will try tomorrow after work, but so far for a small mod like this it is very promising and pretty revisable if you don't like it.