Perhaps it's time to clean it a bit. Unscrew top, and use something to clean the contact.. i use cape cod polishing cloth, rub it a bit, then use a cotton towel/buffing cloth. Next, take out the spring, if its the new one and its not shiney , do the same like with the top contact. I clean my spring every week, and it should look similar to gold. If not, its oxidized a bit, and you lose as much as 0,2v under load. Next, clean the
threads on the main body and on the top. If you have noalox, re-aply it to the main body
threads, but do not overdo it. If you use too much, you will lose voltage under load. Noalox does help a bit with conductivity but only when applied in small ammounts... you only need enough to keep the threads easy to screw/unscrew.
If these steps do not help, re-check the spring, if it's too compressed.. look at the photos with the hot-spring on vendor sites and compare it. You can bring it to the proper size, i even shorted one several times and cleaned it , brought it back to shape and works like a new one.
Also, with mechanical
mods the battery you use makes a lot of difference. A cheap *whatever*fire 18650 will lose up to 0.5v under load with a LR atty, compared to 0,09-0,16 loss from an AW High Drain or 0,25v with 2900mah AW.
Hope this helps !
