Can I ask why is it bad, if everything works now?
Length is all that matters here. The site says they are 69.7mm and solar measured 70mm exactly so they should be fine.
The review refered to a visable defect I believe. Solars cells look fine.
Your probably over compressing the springs as well.
Hopefully you two are not crushing the battery tips.
This goes back to TF choosing the 2nd prototype springs for the Q8. They are a decent compromise, but a bit too tall for certain protected cells.
Just that water may get inside.
Another thought/observation if the o-ring was mistakenly installed forward of the proper groove (see my o-ring closeup pic) That would prevent full threading the battery tube on. As the o-ring would bottom out on the top of the internal head threads.
Same here…. times two.
This scenario makes the most sense of anything having to do with O-rings. :+1:
Hey, mine fits very tightly… I thought I had a problem at first, same behavior… I applied a tiny bit of lube to the o-ring and the inside of the head just before the threads. That took care of it! The tolerances are very good on this light, at least my sample.
Gotta say, this thing is awesome! I got to spend some time in the country with it and compared it to the X7R. The X7R is brighter, but this is focused so well that it is visible in the center of the X7R beam at 120 yards! Also, has much better tint than the X7R.
It is a keeper!!!
I had already cleaned / lightly sanded (very fine grade) the end of battery tube, good thing I stopped where I did.
/\ W o w…… that was a close call…. 
Ha ha, there’s actually a little more tolerance due to the inside of head diameter (smooth, non threaded part) being 50mm and the outter diameter of the raised rib (just above the o-ring) equals 49.52mm.
GOOD…. that leaves you a bit of ‘breathing room’. 
Wow 71 new posts, that must mean something bad or good, bad this time.
70mm length is not too long.
The Panasonic protected cells work and are even longer (and they work fine, not a real noticeable difference compared to 30Qs for example (to answer the question about it ) )
So if cells are charged , work in other lights , have a button top there should not be a problem.
Good it works without oring.
Now can you lube the oring and place it in the correct lowest slot?
Just got mine yesterday. The switch indicator light went out within 20 min but doesn’t bother me. Otherwise seems perfect. It really hits the nail on the head with tint and beam profile imho.
Do we know if yours is from the 1st batch?
All the 2nd batch lights should be fixed with new switches and leds.
Please PM me if it start to bother you! thanks for being relaxed about it.
Don’t know if mine was the first batch or not… is there a number on the box or something to go by?
The screw size is a give away and order time.
DO you have a side by side photo of the differences? Or could you direct us to the post? Thank you.