Extra Magazines - The rules permit pre-loaded magazines (5 shot maximum) in NRA Smallbore Rifle Silhouette. That is one of only a few rules different from NRA High-Power Rifle Silhouette. It is recommended that you have three magazines for your rifle. This saves time at the firing line getting prepared to fire. You can use magazines that have a higher capacity but only load 5 rounds in them. You may not use a magazine for support while shooting.
Spotting scopes are important to help see where your shot hit and where your shot missed. If your spotter can tell where the bullets are going, he/she can relay to you if an adjustment needs to be made. To start with it is not uncommon to see binoculars used. In the beginning if you have anything, binoculars or spotting scope, it is good enough. As your ability to hold on target improves your spotter becomes more important. If you are going to keep shooting a spotting scope can be a good investment. The tripod is just as important as the scope itself. If the scope is on a flimsy tripod, it will not be steady. As in most optics, you get what you pay for. I chose the low-medium range Burris Landmark 20x-60x -80mm - $190. It is real good up to 40x or so and starts to lose quality at the higher magnification. There are numerous high end products from $300 to $3,000. If you must (or just) settle for something in the $100 range, you will definitely be sacrificing quality. I am satisfied with the one I have and it works well enough. There is definitely better quality in the $300 - $500 spotting scope.
Don't forget the tripod. If you are remotely serious about getting a spotting scope, do not go real cheap on the tripod. Check out a variety of tripods before you commit to one. A fantastic spotting scope on a sloppy tipod can equal a crappy spotting scope on a solid tripod.
Shooting vests can be practical for carrying your magazines and notes but can be important to help steady the rifle. I now use a heavy leather vest. It provides a solid non-slip resting place for the left elbow that the thin fabric one does not provide. This is just as important for the rifle butt resting against your shoulder, not to mention a little cushion when shooting a high power rifle. If you are just starting/trying Rifle Silhouette, it is not the most important piece of equipment. As you get better at the sport, you will get a few more steel targets down with the heavy leather vest.
This is a commonly overlooked area of NRA Rifle Silhouette shooting. Your feet are the base of your standing position. Obviously if the base is not solid it will not be steady. I have torn ligaments in my right knee and ankle from a long ago motorcycle crash (the car won!). I wear shooting boots to help support the ankle. These are good and can add a little to the average persons stability but are expensive and normally not worth the expense. What you do not want for NRA Smallbore Rifle Silhouette shooting is soft soled, rounded tread, athletic shoes. Anything with a soft sole will lower the feeling of balance to the feet causing more wobble in the body trying to remain stable. Picture standing on a thick foam pad and trying to stand in steady hold. It would be difficult. It is exactly the same principle in soft soled shoes but just not as extreme. Avoid the walking shoes/boots with the thinner sole at the toe. Great for walking but the rounded bottom offers less ground contact area for standing support. The diferences I am talking about might be minor but, so is the amount of error required to miss the target. The best is something with a flat sole or one with an even heel-toe relationship similar to what is pictured here.
Many people have count-down timers to know how much time they have left in the 2-1/2 minute firing sequence. They are set to count down from 2 minutes and 45 seconds. They are started when the Range officer calls for the "Ready" or "Listo" command. There are a wide variety to choose from and not the most expensive investment you will make. I rarely need a timer at all but, on a windy day, I would not want to be without one. It can let you know if you can buy some time while the wind is up and you wait for a calm.
Just for the information... We use the "Invisible Clock" which is not recommended for everyone. It is a bit confusing on getting set properly and, every time the battery runs out, you need to reset it. The battery does last for a long time, maybe a year ( I have not logged it to know exactly). The numbers are quite small and hard to read. It has a vibrate setting which is its only good point. We have alarm #1 set for 60 seconds remaining, it vibrates for 5 seconds. We have alarm #2 set for 30 seconds remaining. Alarm #2 vibrates for 5 seconds pauses for 5 seconds and vibrates again for 5 seconds. So we know by the end of the last vibration there is only 15 seconds remaining. It is nice to not be required to glance at the clock to determine the time. However, if you are curious and glance, the numbers are fairly small and can make it difficult.