I agree. There's no insulator at the top of the SMPL & clones of the SMPL. If you look at, say a 4nine mod, there's a massive peek insulator around the 510 threading. They fixed that with the SMPL+ by Epic Design...as for an atty to go with it, check out the hobo v3.1, it's compact and I know for fact that the positive contact protrudes enough. Also I'd be interested in seeing a Low Pro Atty on top of a SMPL. 10mm in height + wide bore DT with a honeycomb inside, it's an awesome tiny atty. if you want a tank to go on top, you can't go wrong with the 528 customs Monster (kayfun) v2 or v3.No, it IS a problem with the SMPL. It's a dangerous design.
And the Derringer may seeM like it was made for the SMPL, buuut it was made for the prax1s mod as the derringer is made by prax1s