Its been mentioned above and I touched upon it ( unfortunately edited to the extent that the context was lost ) on the piece to camera I did at the DSC1 on Harris/ Shooting Show. Good ( not necessarily expensive ) kit alleviates a lot of worry - most common hardware failures on the test centre on the scope.
There's a whole tribe of special gremlins that inhabit DSC1 range paperwork - it the only explanation I can think off for their sudden appearance on the Assessment day!
If in any doubt, dont hesitate to discuss it with the range staff. Many courses have a practise range session the day before the test and the opportunity to use a course rifle. You have enough spinning around your head at these times, and a strange issue for you will likely be something experience staff have seen many times.
But by far and away the biggest hurdle sit inside your head. We are all different, similar perhaps, but different. Taking the test does create nerves and those affect people in different ways. Be aware not ashamed of it - honestly.
I suffered nerves when I took my DSC1 - actually NSCC; and I had to cope with keeping my black powder dry and frizzen tight
. Some candidates show no nerves at all - but its a fraction of a percent and I suspect that of those it really is a case of not showing as opposed to not feeling nerves.
Stress can do strange things - most of which are unhelpful in terms of holding a rifle steady and true. I have had very professional shooters - close protection police/ military personnel amongst others. A number admitted the DSC1 test was the most stressful shooting they had done in a long while. But their experience and acceptance of that stress helped them through. There's no ego/ machismo element to any of this - none.
If you are aware of it and open with the range staff then you are a long way to a solution. This is why its important to make full use of any practise sessions. Some courses have to make use of range set ups where a number of shooters proceed simultaneously, others take things one at a time. Its worth checking when booking and weight this up in your choice of provider. For some a 'group effort' actually helps, for others 'one on one' makes a world of difference.
You have three attempts for each section. But in truth if it is stress/ nerves that are the problem it is rare they'll improve on the second attempt and the third( and last ) attempt is really going to turn up the heat.
Be selfish. Nowhere in the Assessment rules is there a requirement to do any assessment against the clock. There obviously has to be a bit of pragmatism employed, but try not to feel rushed. It is only once you press the trigger that the die is cast. If it doesnt feel right or you believe the shot will not fly true, dont shoot.
Everyone is different as said, but I'd propose that the most frequent problem is that people over think things. That may help some, but for the most part it just ramps up the pressure. You know you better than anyone else, think about what will work best for you.
It generally is helpful to spend some time visualising the test. Just like top atheletes - programme yourself. Visualise the whole process - but make sure every thought is positive. See and feel a perfect hold and release, see a nice tight group centred in each target. Just a few minutes each day for a couple of weeks beforehand will make a difference.
Under stress you will most likely do what you have been properly trained to do. The kicker is 'properly trained'. It is spookily easy to train yourself to do one thing when you believe you are training to do something else! Toxster raised the issue of the aiming mark on the deer target - the centre is a bit away from where many traditionally aim. You can be told/ tell yourself a dozen times where that point is - and under pressure revert to what you may have already programmed in.
SD is a great resource, but I always recommend including the centre where you will be going in any query of concern you have. 1. they are the ones there on the day. 2. it helps you get to know them in advance and 3. it makes them aware of your specific concerns - I dont think there are any providers who wouldn't then go out of their way to help.
Good luck.