LABRADAR - Just how good are they? - some more testing

[DaveMc]

Hi Folks,
Peter Smith came up to the 25m indoor range yesterday and we had a little play with two labradars either side of a 308. We quickly loaded some 155 grain hybrids and fired 20 shots through whilst doing some preliminary testing of components. Without going into detail of the component testing (as that requires more work) we would like to share the side by side readings of the chronographs as they were quite remarkable. I am hoping Peter might chime in here with some more detail and graphs but I will give the raw (screen) data now to kick it off. A couple of things worth noting are we lost one shot on Peters chronograph but it was positioned to the left up the wall of the range and might not have been getting as uninterrupted a reading as Shanes on the right. We also had Peters slightly closer to the muzzle. Settings had to be altered for indoor use including setting to low power and reducing the distances for the v0v5 settings to 4,8,12,16 and 20 yards. This would be worth repeating outdoors on full settings.
Shot # Machine 1 Machine 2
1 3053 3055
2 3063 3063
3 3066 3067
4 3048 3047
5 lost 3056
6 3065 3066
7 3069 3067
8 3067 3067
9 3066 3065
10 3080 3080
11 3075 3076
12 3069 3069
13 3064 3066
14 3077 3080
15 3067 3066
16 3077 3076
17 3072 3070
18 3082 3083
19 3067 3068
20 3072 3072

average difference = 0.21 fps
sd of difference = 1.36

Now - remember the sd of the differences is the square root of the sum of the squares of the individual radar error sd's. That means the actual sd of the errors for each radar is smaller than this and likely to be < 1fps. - TRULY REMARKABLE

This was an effective sample of 19 shots - whilst not as large as we would like for statistical power or publishing in a scientific journal - it is still a decent sample size and big enough to give us a lot of confidence in the results. We will endeavour to do more of this whenever possible and demonstrates that Labradars (and preferably twin ones) can be used as a very good method of measuring when testing components and combinations for velocity spreads

[pjifl]

I have no doubt that the LR opens up new avenues for critical assessment of ammo. It would be nice if others could confirm a similar LR accuracy by comparing 2 units.

I know that at shorter distances compensation can counter ammo velocity variation but at 1000y, where most matches are decided, V consistency is a key factor.

LR is a perfect tool to assess this. And it is one of the few things that may be tested at shorter range and on windy days.

Peter Smith.

[williada]

Excellent work guys. . Confirming such low variation will give meaningful results when testing primers etc. Combining information with other measures from your pressure strain gauges will give a nice picture indeed.

[Hahndorf 1874]

We're the two used US spec.or the lesser one Labradar said they will only sell in AU.?

Cheers Mal.

[pjifl]

Shane's was bought in the US, mine was probably the first into Australia and as far as I am aware is the same as what was sold in the US at that time.
Since then, LR seems to have a problem with supplying into Australia. I have heard of various reasons - one being that returns for repair introduce problems and they do not want to know about us.

The only different specs I am aware of are lower RF power limits - mainly for various European countries but maybe this has changed. If true, this would hardly impact on accuracy as long as it has acquired.

I believe that higher power would only impact on maximum tracking distance but to me this is of very limited importance anyway because deriving BC from individual track Velocity readings can never be very accurate unless projectiles are tracked all the way to the target. Very seldom does tracking reach 100y or even 80y in practice.

Projectiles at 3000 f/s seem to be acquired by both units at about 6 to 7 yards from the muzzle and of course readings are taken each 1 m Sec which means every yard.

I believe one of the reasons LR is inherently the most accurate for determining velocity is that in practice each projectile has recorded maybe 40 velocities which are then mathematically processed to extrapolate and average a muzzle V.

Peter Smith.

[ajvanwyk]

I want one !!! Would there be any issues foreseen if I have a mate in the US buy me one or is there a way to buy them locally ? Do anyone have ideas on cost in AUD ?

Thank you,
Albert

[pjifl]

I originally wrote a small summary of the LR at

viewtopic.php?f=5&t=7455&p=62960&hilit=labradar#p62960

It fairly accurately summarizes the pros and cons of the LR and MS and if you are thinking of acquiring one is maybe worth a read. At that time there was no was to assess the accuracy of the LR which now seems confirmed.

For all but the most discerning use, a MS is still a fairly good option.

Peter Smith.

[saum2]

Good too see your back on deck Peter,
Could I be controversial and say they (Labradar) are a bit finicky to set up??
we used 2 together at Lower Light some weeks ago and I thought why bother as no amount of adjusting and one unit wouldn't read at all. Is this normal??
Geoff

[pjifl]

I agree that LR is far from perfect and Geoff's comments are valid. That is partly why I put in the link to my previous material where I try to get it in perspective with the MS.

I think it is very common for many LR's to have problems acquiring and this problem seems erratic. The best fix seems to be to place within only a few inches of the muzzle. Far closer than their instructions indicate. So close that it is very uncomfortable and not a nice feeling adjusting the unit. Even with the bolt OUT. Muzzle also in the plane of the LR surface.

For many uses I think the MS is more suited but for some applications - like investigating primers and Vsd down below 3 it is probably the only realistic device to use.

I am still not shooting yet. Maybe in another month.....

Peter Smith.

[Matt P]

I really struggled with mine in the beginning, the aiming device on the top of the unit is totally fu&@$?& pathetic. Once I added a small length of square tube to v slot, it changed how easy the unit became to set up but like Peter I have the unit next to the muzzle.
Matt P

[BATattack]

Good too see your back on deck Peter,
Could I be controversial and say they (Labradar) are a bit finicky to set up??
we used 2 together at Lower Light some weeks ago and I thought why bother as no amount of adjusting and one unit wouldn't read at all. Is this normal??
Geoff

They can be a bit fiddley to set up and using them at LL was a bad example. If you set it up properly (ie lay on the ground behind the unit and aim it carefully) they work much more reliably. Throwing it on the ground and pointing it in the general direction doesn't often work.

When I get a chance I'll make a bracket with pic rail and attach a small ebay red dot sight to the outer frame.

[DaveMc]

Good too see your back on deck Peter,
Could I be controversial and say they (Labradar) are a bit finicky to set up??
we used 2 together at Lower Light some weeks ago and I thought why bother as no amount of adjusting and one unit wouldn't read at all. Is this normal??
Geoff

Geoff, whilst this was certainly true. The readings we got were highly correlated to plot position. Giving me a good "calibration" to determine how much was range elevation vs load. It was certainly worthwhile.