I mostly use my nem with AW 18490 but once in a while I use my only efest 18350 but I need to unscrew a lot the button for it to fit (the button sleeve doesn't cover the main tube) leaving a 1mm gap there that I don't like and also makes the lock ring too far so I need to give it a lot of turns to lock it. I've tried adding the "kick ring" (I'll get into that later) and it's too big so I don't get contact... is this a problem with all 18350's or just with efest button tops??
now for the kick ring... I've never used a kick nor have one but I always thought that you used a kick with a 18350 along with the 18500 tube and the 18490 bat with the 18650 tube, so is the kick just for the 18650 or why is it much smaller than the difference between the tubes?
The smallest ring is for a 2 cent fuse.
The next size up is for an 18490/18500, or kicking either 18650 or 18350 batteries.
The next size up is for an 18650, or a kicked 18490/18500.
For an 18350 and no Kick or fuse...don't use any of the rings at all.
When I kick a flat top Efest 800mah 18350 in my HCIGAR brass clone, I also get a thread or so overhang on the button end with some of my atties flush mounted. Some atties can be adjusted a bit to take up the slack and be flush mounted. With others I just have to choose...let a thread or two hang out at the button end, or loosen the atty some and make room with the mod's center pin (a less than perfect flush mount on the atty...but it still works very well).
You could also just take the slack up with the atty mount and center pin, and add an O ring between the atty and the mod if 'air-flow-control' is an important issue for you.
You might have luck if you used a 2 cent fuse with the smallest ring (grind/sand the post side of the fuse as/if needed)...or use some other type of battery spacer with the fuse ring, such as a magnet spacer (be sure the edges are well insulated if you use an un-fused magnet or other conductive spacer). When I make an un-fused battery spacer...I either press/glue a magnet tightly into a thick plastic/silicon/rubber washer, or solder it to the pcb of a dead PTC (VapeSafe, ShortStop, 2Cent, etc.) fuse (I jumper where the dead fuse was of course).
An option would be to grind one or both of the mod's contact pins down some (I'd get some spare pins first tho', and you'd probably loose the silver plating at the contact point). Personally, if I were going to do this I'd probably grind the part of the center pin that touches the atty...you might loose some or all of the 'screw driver slot'...but does anyone use that anyway with a nemmy style mod?
Another would be to get an 'extended/longer' center pin for the positive end and use the small fuse ring.
Another would be to work on the atty some (grind away some threads, adjust center pin, etc) so that it doesn't fit as deeply and will flush mount.
Another is to spread the play out among all the various sections.
With some of the clones it is possible to adjust the black delrin part in the top of the mod (force it up or down inside the metal casing). I'm thinking this probably wouldn't offer much help, but it 'might'.
Or, as I do...just live with the slight over-hang in the bottom button upon the rare occasion I kick an 18350 and have a deep seating flush mounted atty. For me it's usually less than one thread overhang...so no biggie.