I bought 2 Samsung INR 3.7V 2500mah 25R 18650's today. I want to run them in my tugboat box mod. the question is though is it safe to use them at .2 ohms? my efest 3000mah and VTC5's work great, just want to be sure before I use them.
You bet, with plenty of headroom. 20 amp rating on those batteries and they've been tested to certainly live up to at least that. .2 build will be pulling theoretically 21 amps on a full charge, each battery in parallel will be taking 10.5 of those amps.