Labradar -- how critical is ......

[ShtrRdy]

.... the position of the Labradar with respect to the muzzle?

I finally ordered a Labradar from Sheel's yesterday and started reading the owners manual online. For a non-brake muzzle they recommend lining up the Labradar with the muzzle. When shooting off a bench this seems difficult to do since the muzzle will be some number of inches in front of the bench.

Can I set up the Labradar on the bench alongside the rifle?

 

[Varmint Hunter]

The positioning of the LabRadar isn't very critical. Several inches back from the muzzle will work fine. I put the LabRadar on a tri-pod next to the bench and about 9-12" to the side. I can reach the buttons from my shooting position.

If you use an inertia trigger, you can put the LabRadar anywhere as long as its properly aimed at the target. Aiming the unit is easy because it isn't critical. I have, but don't use, an inertia rigger.

 

[QuietTexan]

Can I set up the Labradar on the bench alongside the rifle?

I do. I put the LR on a little tripod next to the rifle, usually quite a bit back from the muzzle. But I do it the same way every time.

I used to use a big tripod and worry about getting it positioned correctly but then I saw people using the quad-pod that goes over the shooter while laying prone and it hit me that if that works being that far away, putting the unit on the bench won't be a problem.

The new little tripod (link below) fits into a Pelican 1520 with the LR, battery backup, and inertia trigger. Not my case but mine is set up the same way, except a longer cut out on the left for the mini tripod. An Apache case from HF in the same size works just the same.

I found the 2GB cards on Amazon to use to store the data, makes transferring to the computer very easy. I started using the inertia trigger on suppressed rifles, now I use it all the time for sake of consistency.

Desktop Mini Tripod @ Amazon

 

[338 dude]

.... the position of the Labradar with respect to the muzzle?

I finally ordered a Labradar from Sheel's yesterday and started reading the owners manual online. For a non-brake muzzle they recommend lining up the Labradar with the muzzle. When shooting off a bench this seems difficult to do since the muzzle will be some number of inches in front of the bench.

Can I set up the Labradar on the bench alongside the rifle?

Yes, you can do that. If you have problems with it, not going off, you have a few choices you can adjust the sensitivity you can use the supplied microphone or you can buy an inertia trigger.

 

[just_jon]

That's how I set mine up. I use the tripod from LR set as low and as far forward as possible on the right side of the bench. This puts the muzzle 5 or 6 inches in front of the LR which means I don't have to reposition when switching between braked and non-braked rifles.

 

[entoptics]

As with others, I set the unit up well behind the muzzle, both for blast reasons as well as reaching controls.

I do believe there is some minor (hair splitting?) "geometry" influence in the readings though, which is accounted for in the settings for rifle distance from the muzzle (6", 12", 18"). I believe this is to account for the variation in "straight line distance" caused by the offset. Pythagorean theory and all that, the same as when shooting up or down hill (line of sight vs horizontal distance).

By defining the offset, the radar can account for that extra little distance the microwaves have to travel on the round trip from the radar to the bullet and back.

For reference...

Left/Right of Bbl (in)	Bullet to Bbl (yds)	Bullet to Radar (yds)	% Dif	Velocity difference at 3000 fps
6​	10​	10.00139​	100.01%​	2999.58​
12​	10​	10.00555​	100.06%​	2998.33​
18​	10​	10.01249​	100.12%​	2996.26​

It should also be noted, that the difference between "bullet to bbl" and "bullet to radar" will change (decrease) as the bullet travels down range.

As you can see the variation is pretty small, but the math is pretty straightforward, so it's cool that the LabRadar software has an option to account for it. Minimize error when you can, right?

Since LabRadar calculates velocity based on the change in return time from reading to reading, the absolute distance the unit is behind the bullet doesn't matter, only the perpendicular offset from the bullet's line of travel, so how far back or forward you set the unit shouldn't matter, only how far off to the side.

Also, if you always set up your radar the same, then this should only affect the accuracy of your readings, and not the precision, as the error will be the same from shot to shot.

 

[Panhandlin Pat]

If you're shooting suppressed go ahead and get an inertia switch. Will save you some frustration! Unsuppressed on my home range I set it right in front of me, probably even with the front of the scope so I've got east access.

 

[Axl]

As the others have said, you can have it quite a ways back from the muzzle.

 

[Darryle]

This has worked flawlessly for me, no ports out the bottom so no interference.

I am in the process of making a custom base so I don't have to swap heads on my Bog Pod.

 

[Mrvmax]

I use a trigger switch and never worry about it

 

[Jeffpg]

Air Gun Trigger Adapter

Product UPC: 708022203613 The Air Gun Trigger Adapter kit is used for guns that do not discharge sufficient muzzle blast to trigger the radar. This adapter should only be used on Air Guns, Rimfire or center fire cartridges that have little or no muzzle blast and some suppressors. The Kit...

buymylabradar.com

Is this the switch that you speak of?

 

[338 dude]

Air Gun Trigger Adapter

Product UPC: 708022203613 The Air Gun Trigger Adapter kit is used for guns that do not discharge sufficient muzzle blast to trigger the radar. This adapter should only be used on Air Guns, Rimfire or center fire cartridges that have little or no muzzle blast and some suppressors. The Kit...

buymylabradar.com

Is this the switch that you speak of?

That is an acoustic trigger a.k.a. microphone. The other trigger is an inertia trigger I believe JLK makes one.

 

[QuietTexan]

This is the one I use:

Labradar Trigger Gen 2

This is the gen two trigger for the LabRadar chronograph. It will work on anything from a 22LR to a big bore rifles. The trigger works great with suppressors and crowded ranges. The new, removable …

jklprecision.com

I got the magnetic and pic rail attachment, but since I shoot bolts 95% of the time when I do shoot an AR I just wrap the cord around the scope base instead of using the pic adaptor and it works fine. Magnetic is great on the side of the action.

One thing to watch out for is you'll have to get in the habit of making sure the unit is armed before each shot, and there isn't an error code up. I can run my actions smooth enough to not trigger the inertia trigger accidentally usually, but sometimes popping out a max load or if I'm shooting in a hurry you can accidentally trigger an error. Usually I get "dead" shots, meaning it picks up a D10 velocity but no other distance so it doesn't miss the real shot, but maybe once or twice a range trip I'll pop an error code.

 

[Dr. Vette]

I'll be the odd man out - I found that it was very sensitive to placement of the end of the muzzle. I would often "miss" shots if the muzzle was too far forward, which wasn't far at all.
Switching to the JLK trigger cured that problem.