I use a labradar myself and love it, but the OP is using his indoors. I know the labradar has been used in large indoor shooting ranges, but have never heard of someone using it in a house. Has anyone tried using theirs inside a home? Setting mine on the deck 1 foot to side of muzzle I typically don't pick up readings until 5+/- yards in front of the labradar. Minimum offset to side on labradar can be set to 6 inches, I don't know how close it picks up when set and properly used at that offset.
If you read a lot about the labradar you will see a small but reasonable number of people hate it, my personal opinion is the majority of them are too stupid to follow directions and use it correctly, and some have a defective unit and didn't pursue warranty work. The microphone embedded in them has a great amount of variability in its sensitivity, there have been quite a few that had to be replaced under warranty. Sucks the company doesn't source a better internal microphone, but that never bothered me. I did my research on it and had built a recoil trigger for mine before it was even delivered and had a USB battery bank, I have never even opened the battery compartment on mine(read reviews and if you go for the labradar you won't either), usb battery banks are cheap and work great. I only used the internal microphone on mine once, just about 20 minutes after fedex dropped it off at home, and I only did that out of curiosity. It worked great on centerfire handguns and rifles, but playing with a 22lr rifle shooting standard velocity CCI I could not get 50% of the shots(not using my suppressor on it) and I was lined up less than 1/2 inch from where the instructions said to be and tried moving all around that point, sure was glad I built a recoil trigger. Don't waste your money on their air rifle external microphone, it works but is much more expensive than a recoil trigger that always works and is easier to use, lowest power pcp I've used it on was when tuning my Uragan, had it down to 17 ft-lbs at one point and recoil trigger still worked. I don't know if it would work on a sub 12ft-lb extremely heavy target pcp, you would have to test and maybe need to resort to getting the air rifle mic from labradar.
Aiming one is critical, the center of the radar beam is small, small changes make huge differences in signal to noise ratio. You will need an aiming device that is absolutely repeatable to a very small margin, less than one foot off at 100 yards every time, if you want to get the best out of the labradar. I did lots of testing with mine and it is that sensitive to aim and getting best radar returns. One problem you may have shooting indoors in a house is you may be shooting too much accross the units radar beam. From the testing I did at 114 yards, I know shooting 12 feet to the left of where the true center of beam is from the right side of the labradar causes issues, the projectile flight at that point is too much of an angle to the beam to get accurate results, that is for the entire flight once it is picked up, not just when it passes past the center of the beam. For very short range use in a house, I wouldn't be surprised if your projectile aimpoint would have to be a few inches from the labradars aimpoint to keep the angle between projectile flight and beam low enough not to cause issues. Testing would be required.
Honestly, as much as I love my labradar, if my use was going to be indoors at very short range with air rifles, I would not spend the money on one. I'd just get a decent optical chrono with built in lighting, and have no flourescent lights(or even led lights running on PWM) around when using it.
edited to add: bluetooth, it runs on low power bluetooth, if you have any bluetooth devices active anywhere near it, it will cause problems. You need a clean RF environment in the bluetooth frequency to not end up bitching and moaning about it disconnecting constantly. Most common complaint you will ever read on the labradar. I've had my labradar connected for hours at a time without issue, I live in the country, no bluetooth devices, for that matter no rf devices, used at home at all except when I'm on my tractor with sound cancelling headphones.
