I know how you feel, I have a 640 thermal and keep going back and forth with need/want conundrum. I'm in the market for a thermal clip-on that won't make me more poorer.
I have seen the avg. velocity stay and even decrease with increased charge weight. Chronographs are funny gadgets, that are affected by many variables. Even the pressure of the hold of the rifle can change the averages. INMOP 6 shots are meaningless in regards to SD, too small of a sample...
All Prices FTF, Will ship at buyers expense. Located In So. Dutchess Co.
AR Parts: price as shown OBO
1. Lightly used 14.5 5.56 barrel upper (MB pin&welded) $500
2. New Foxtrot Mike FM9 upper parts kit $250 **SOLD**
3. (2) milspec safety (3) milspec trigger guard $10
4. CAA flaslight...
Food for thought on the subject.
Night vision is better for navigation, and sees thru glass (driving)
Night vision will miss game in brush/forest/shadows
Thermal does not see thru glass
Will ID anything with heat signature
Can be used day/night
Many are now fusing NV and thermal together.
Used Ultradot Matchdot 2 red dot sight 2-4 MOA/+ $175 FTF Or Trade for Federal 210 Lg Rifle Primers
Located So. Dutchess Co. will meet in Putnam/N. Westchester