OzFclass

AlanF wrote:My current thoughts on chronos : Magnetospeed if used correctly seems to be the most useful, because it remains stable regardless of location, lighting conditions etc. So even if its shot to shot precision isn't quite up to the ones with a longer base between sensors, it is a good way of comparing velocities at different times. Also good is its ease of setup. The main thing against the MS is that it adds weight to your barrel so will affect your tune. However for tuning, you can use a skyscreen type and directly compare it with the MS before and after. I'd be interested to hear more reports on Labradar.

Labradar is great

Matt P wrote:

AlanF wrote:My current thoughts on chronos : Magnetospeed if used correctly seems to be the most useful, because it remains stable regardless of location, lighting conditions etc. So even if its shot to shot precision isn't quite up to the ones with a longer base between sensors, it is a good way of comparing velocities at different times. Also good is its ease of setup. The main thing against the MS is that it adds weight to your barrel so will affect your tune. However for tuning, you can use a skyscreen type and directly compare it with the MS before and after. I'd be interested to hear more reports on Labradar.

Labradar is great

Agreed!

BATattack wrote:

Matt P wrote:

AlanF wrote:My current thoughts on chronos : Magnetospeed if used correctly seems to be the most useful, because it remains stable regardless of location, lighting conditions etc. So even if its shot to shot precision isn't quite up to the ones with a longer base between sensors, it is a good way of comparing velocities at different times. Also good is its ease of setup. The main thing against the MS is that it adds weight to your barrel so will affect your tune. However for tuning, you can use a skyscreen type and directly compare it with the MS before and after. I'd be interested to hear more reports on Labradar.

Labradar is great

Agreed!

Hope I'm not going off topic but I see that you cannot order the LabRadar on the internet directly. Is that because it's not allowed to be used here or because there is a local dealer in Aus.

Tnx.

They won't export due to the restrictions on privately owned radar strength. . . . . . They are probably concerned someone is going to link them together in an array for accurate targeting and shoot 180gr bergers at a battle ship or something ?!?!

BATattack wrote:They won't export due to the restrictions on privately owned radar strength. . . . . . They are probably concerned someone is going to link them together in an array for accurate targeting and shoot 180gr bergers at a battle ship or something ?!?!

HAHAHA that's funny and sad... because it's probably true... I guess I'll have to go to the states or get my mate to post it... the things we do

Yeah I'm sure you can sneak one in. . . .under the radar!

Hi just a few comments after coming back to this topic after a few weeks more testing with various chronographs.

Firstly Bryan Litz's articles on chronographs was a great read http://www.appliedballisticsllc.com/Art ... hapter.pdf

But a few things concerned me that I would like to point out to the readers. Firstly the very poor results from the PVM. We have had 3 of these units up here and find them quite good but it is important to set up correctly and with shot placement through centre of screen. When I looked closer into Bryans results I saw he actually did get very good results in position 3 (figure 15.15) with a st dev of errors against the Oehler of 1.6 and 1.1 for each unit respectively - that is assuming no error with the Oehler which is incorrect so some part of this variation would be coming from the Oehler unit - relatively speaking if these units are set up in the correct area then they are very consistrent shot to shot. Looking at his set up with all in a row it is not hard to see why if he place shots in the top left and right corners of the screen by trying to achieve positions 1,2 in the triangular frame then the shots may have been outside the optimal reading area for these chronographs. Whilst Our testing would concur with Bryans that there is some difference between the reading on the PVM and others such as the Magnetospeed (around 20 fps in our case) the accuracy for shot to shot testing of sd can be very good.

The labradar seems capable of very consistent readings too. Those chasing ultra low SD (say <6) may find it nigh on impossible to achieve decent consistent results with a lot of brands due to the sampling errors of the chronographs swamping the true velocities and need to do this type of testing with some of the better brands. Oehler, PVM, Labradar etc.

Magnetospeeds are great. Highly portable, Not reliant on light and can be used to get a relative velocity measurement consistently with a relative degree of accuracy but do not expect them to measure down to ultra low sd when you are chasing that final fine velocity spread.

There's a Labradar for sale on used guns.
Matt P

Interesting that it has 0.1% accuracy at 3900 fps.

That would equate to 3fps for our loads running around the 3000 fps mark.

Worth keeping in mind when you are chasing sub 10 fps ES.

Personally, I run with the group analysis on paper. I use the chronograph early in load development to give me a rough indicator of velocity. Low SD's are important and you get a consistent picture of that after a few tests rather than one chronograph outing.