Labradar & bullet weight?

[MikeT49]

I don't have white adhesive tape holding my glasses together ie my computer skills suck. I set up at the range. I shoot several different guns. I do not change anything on the LR. Do I need to change the bullet diameter input for each different cal? How much does it affect the velocity reading? I have seen that it does track very well with my magspeed. IIRC however, for different calibers the relationship between which one reads lower flip flops.

Edit: I changed the title, would you believe I meant weight not diameter?

 

[David Christian]

I have not noticed that the caliber setting matters.

 

[F Class John]

I’m not aware of the bullet info needed for anything other than data beyond capturing velocity. I never change mine.

 

[Laurie]

It can affect the number of failed readings for a marginally misaligned set, also how far down-range it tracks the bullet and gives retained velocities. the larger diameter the bullet, the greater the reliability / tracking distance. (Living in the UK, we see this even more than North Americans as you're allowed a much more powerful transmitter - yet again we suffer from damned and restrictive EU regulations.)

When Bryan Litz got a very early US model and reported on it on this forum, he did note that it wouldn't work with 0.224 military type 55gn FMJBTs. it was assumed that this was a combination of the small base area allied to a concave core rear surface which the spoiled radar return. I've never bothered resetting it for calibre - in fact, didn't even realise there is such a facility.

 

[F Class John]

That’s interesting information above. When I had my first model and was having trouble I called them and I seem to remember them telling me that none of that information actually mattered for capturing velocity. They were more concerned with telling me the distance off the muzzle and the orientation to the target is all that mattered.

 

[Laurie]

hem telling me that none of that information actually mattered for capturing velocity.

I've never given any weight to this data, although I know people who claim it proves their chosen bullet has the expected BC value. With our low-power version, 55 yards is about as far as the radar reads downrange with all five bars lit for signal strength, but that's for 30-calibre bullets. Readings with 6mm terminate closer to the muzzle and I presume it'll be still less for 22s.

 

[LRPV]

Small bullet bases are harder to pick up and the smaller and faster they are the more precise the settings need to be but that is limited to offset setting, muzzle position and aiming of the LabRadar. When shooting 22 caliber boat tail bullets about 34-3500 it becomes difficult to aim precisely enough to pick up every shot. Under 3400, I’ve not had issues. Over 6mm I’ve not had issues but I also don’t have a 6mm that shoots over 3200 anymore either. Settings inside the machine other than offset and trigger level don’t make a difference for me anyway.

 

[whatsupdoc]

There is no bullet diameter input, there is a bullet weight used for power calculations.

 

[MikeT49]

There is no bullet diameter input, there is a bullet weight used for power calculations.

You are correct. Weight is the bullet input parameter not diameter. Old fart moment. I change nothing while shooting. I checked my range notes. For the 20P the magspeed is about 10 fps faster, for 22-250 about 5 fps slower, for 25-06 about 10 fps slower.