Only thing I am aware of is the CARM mags.
I looked for the best place to place this, so I hope it is the right place. ;-)
It is not often that I recommend a non-OEM solution.
But in this instance I am going to make an exception. And, do, please, understand that this is not a recommendation by DIANA, but by CCA/HM
I received a "rant" from a good friend about how the Stormrider (the DIANA version of the multifaceted little gun) was a good gun, but the magazines kept breaking.
Now, I have not broken a mag, BUT, neither do I have youngsters to teach shooting to, so . . . I started searching for alternatives and came across the CARM mags.
Purchased one mag and one SS shuttle in 0.177" cal and tested them.
Short pellets, long pellets (Predator), WC pellets, Domed pellets, Streamlined/Baracuda style pellets, Piledrivers, even Slugs.
Absolutely no problem in feeding/jumping one chamber, or double loading °WHEN THE BARREL HAD THE APPROPRIATE CHAMBER!
They load in a more conventional way (from front to back and from the last chamber to the first).
The inserted pellet itself is the stop for the rotation, so no need to hold the mag, nor need to load the last, then the first and so on.
Really well made.
Post from the country of origin takes a LONG time so, be patient.
It is worthwhile.
Keep well and shoot straight!