To be fair I switched lenses into each others laser and the results are no different, both NDB7875's performed the same.
The G7 was slightly wider in both lasers than the 3 element when focused at 14 feet.
Looking at the far field focus the G7 is pretty close to the 3 element and at 2-6 feet the G7 pops out a flame kernel better than the 3 element.
The G7 does focus near the end of the threads of the standard 12mm module.
Focused to infinity the G7 IS NEAR THE END OF THE MODULES THREADS, but it's working now that I am using the 9mm spring.
I was mistaken, the 9mm spring will work, it's just a close fit.
In my defense the focus is touchy, a tiny movement makes a big difference.
These G7's are a lot like single element - 3 elements. They are stronger up close but they focus near the end of the threads.
Now that I discovered I was wrong about the 9mm spring, it will fit the G7 I see that the G7 focuses just about the same as the 3 element, but it burns better up close, a flame kernel pops out easier with the G7 and at far field they look the same focused to infinity.
In my defense it was hard to get a fair assessment of the G7 without using the spring because like single lenses they can be touchy, with the spring it seems to be a stronger 3 element type range of focus via of a single element.
It may be that some of what's clipped by the 3 element gets through the G7 and with less glass more power as well.
Now we just need someone with a LPM to test them and give us some numbers.