If anyone ends up with their Champion 25 round banana, and has trouble with it, please see my thread/posts about needing to file a small amount off the sides of the grey part...the part that enters the mag well. There's a little rib of plastic that makes it a few microns thicker, probably to fit the M70, and in MY JW-14, that was causing the mag to "pinch" together just enough to prevent the next round from popping up.
I am happy to answer more specific questions by PM, but when you get the mag, you will see this "rib". Try YOUR rile first though, because they are not going to be all exactly the same!
You may NOT need any filing.
If anyone hasn't seen this:
This is my JW-14 from SFRC, with the Champion banana (which I painted btw)
http://www.youtube.com/watch?v=Lc_LviyM1iU
Watch out for flying brass!
And yes, I had forgotten to put my glasses on this one time...I did put my ears in. This rifle has a nice "crack" to it actually, with the CCI Blazers, as the video shows...
As I have mentioned before, I have actually, with the Champion mag, had it cycle with CCI Quiets, and it will function is a SPBAR with shorts! Being careful of course.
As always, when shooting with those low-power rounds, be SURE your projectile has targeted/left the barrel! I have never had that happen, but I have heard of it with those "Aquila" back yarders caps...