I use my LR for load development and haven’t found the need to buy an external trigger. I have been using it since 2015.
Duane
Been using mine since since not long after thay came out. Most
people don't read manuals, and there is the largest problem. I'll
miss an occasional shot. Shot 35 rounds the other day and lost
one shot. Not counting buying an external trigger which I don't
need, The manual has a "trigger source" section. Just set it for
"TRIGGER". It uses the internal microphones to pick up the shot.
The other selection is "DOPPLAR". This setting reads the projectile
in flight and triggers the unit.....The manual also says the dopplar
setting should be used mainly with slower and large diameter bullets.
Set it for "trigger" and punch in the right barrel offset numbers, and
your good to go. Set it for "dopplar" and shoot a high velocity, small
diameter bullets, you will have multiple miss reads.
A comment about having alignment problems is nonsense. The angle
of signal is quite generous. I have mine set up in less then a minute.
I set a 4" tube in the sighting notch and use it like a peep sight, then
throw it back in range bag.....Bottom line ?? Hater's will hate......