I ordered the A6 tube and they fit protected cells, maybe they really sent me an S1 tube?
I also see your S1 tube looks like my A6
Can you give me the bore, outer diameter and lengh of your S1 tube?
Okay, let’s get the callipers. 
Inner diameters are both 19 mm, outer diameters are both 24mm.
Diameter of threaded sections S1 is 22mm (same as Skilhunt), A6 is 21mm.
S1 tube is 37mm long, A6 tube is 35mm long.
Let’s hope they send you the wrong ones too…
So the threads on your A6 tube were lose due to being 1mm narrower? The A6 I ordered the threads feel tight, and it looks exactly like your S1 in the pic. I dunno if the S1 and A6 look the same anyways? For now both the A6 I ordered from bangood (if that is even what I have) is fitting perfect and threads are tight and smooth so I’m not sure what could be improved anyways, unless when I get my 18350s they don’t fit!
My 16340’s fit in it too after I did the spring / magnet mod, they are the same capacity as most 18350s anyways, and are high drain so they can push the LED just fine in turbo. Probably save some weight over the 18350. The 16340 (RCR123) battery is loose in the tube, but apparently under enough tension that it won’t rattle or misbehave anyways.
Jut to be clear, this is the tube I ordered, it looks like the one in your picture.
Also the headband is $3, but shipping is $9? Hmmmmm anything cheaper that will fit? That’s 1/2 the cost of the headlamp!
Ok to make it clear I ordered the A6 tube but in fact I received a S1 tube
It is 37mm long and still a tight fit for protected batteries.
Also the longer threads are needed for a good fit, no sanding down needed
First post edited
Man, how did you get the head loose? Either mine has more glue or I have little girl strength. Don’t want to mar or deform the tube using tools, but I can’t get the damn thing off by hand…
Its not possible by hand, you need heat and tools
The tube is a lot more stable than you need to open it
Is it possible to get the reflector from the R model separately? Would it fit the H03 instead of the optic?
Probably not…
Yes.
Thanks, can you do me a favor and measure the reflector?
Do you think this one from fasttech could fit? https://www.fasttech.com/products/1617/10001275/1209600
I’m not gonna take one apart just to measure the reflector, but when i do take it apart (i plan to put Nichia 219C in them) i’ll report back to you.
I’ve been looking for a reflector as well.
One of the reviews states this reflector is a bit over 13mm tall and just over 17mm dia. I’m thinking it will not fit. The opening in the h03 head is, I think, between 14-15mm in diameter. It’s a very small reflector.
Somebody here on the forum broke his TIR, he/she contacted skilhunt via email (not the message system on the site) and got a new TIR. Don’t know if that person had to buy it from skilhunt or some other company. Think it was for an H02.
Just finished up and I must say this thing is adorable…
No o-rings on it yet (18350 tube that came with my S1 only included 1).
very nice mod!
This is a brilliant mod! You made my morning
I have an H03 on the way and will try the shorty tube from my A6 immediately. And maybe replace the LED with Nichia 219c CRI 90 later.
To get protected cells work you need the 37mm long Astrolux S1 tube
You need the s1 short tube either way, because the threads match well, unlike the A6 tube.
But it’s a bit of a gamble which one they will send you when ordering…
Is it possible to shorten the battery tube (18650 to 18350) in Nitecore HC30?
Anybody did it? Thanks