OzFclass

where can I buy it from and what is best temp range

http://www.shooters.com.au They're in Canberra and usually have some in stock but often limited in temp availability. Otherwise quite hard to find.

I use 450 deg although 475 is better if you can find it. It should not melt more than 1/4 inch down from where the shoulder meets the main body of the case.

My 308 Lapua brass is usually in the flame (single gas torch/drill method) for 6 seconds.

You can also use Tempilaq rated 675/700 deg in the neck, not on the outside where it will just burn and turn to a black grit.

I am running as recommended by Bench Source - 650 deg F for the necks and 400 deg F for the case body as a safety check. I also have 700 deg F for the necks but find the 650 OK. In NZ there is virtually no availability - some laminates firms carry low temp Tempilaq but too low for my needs. I purchased an equivalent product called Omegalaq from Omega in the US. They had no problems shipping it to me. I also got a bottle of thinners at the same time. I have since found Tempilaq on Amazon but didn't check if they would ship to our neck of the world.
There is no problem putting it on the outside and inside of the necks - I polish afterwards always, I don't want shit going thru my dies. Cases need to be clean (I ultrasonic) otherwise oxidation of residual sizing lube will occur and the carbon deposit inside the neck gets even harder to remove once the case annealed. Once I have set up the timing for each calibre case (and recorded the time) I don't use the lacquer.

Hi thanks for your input .after a chance talk I contacted a Brisbane firm temperature control pty ltd they are ordering in stocks of 400 and think 750 degrees as suggested by a metallurgical whizz

Check out you major welding supply stores. They may or may not have templaq as such but we use similar things for pre and post heat temp checks.