A miscellany of tips on biathlon rifles and associated gear.
You absolutely must record the positions of all the adjustable bits on your rifle. You can mark them on the rifle or write them elsewhere, and you can guarantee that if you don't, someone (probably you) will fiddle with your rifle and you will take weeks to get it shooting straight again. If you have the information written down, then you can quickly set up a new stock if you no longer have the old one.
Important bits to record are:
You can tell if a magazine has enough rounds in it by checking the hole an inch from the top: if you can see a bullet through this hole, there are (at least) 5 rounds.
Magazines should only take 5 rounds. If you inadvertently load 6, fire 5 and finish the race with a round in the magazine, you will be disqualified (this happened to Andrea Henkel after what should have been a gold medal run at the Junior Worlds). Therefore:
Magazines go rusty just like rifles - and are easy to forget after a wet shooting session. They need drying and oiling, or they will become very hard to get on and off the rifle.
If you take your rifle off by grabbing the foresight tube, the black colour will quickly wear off. Shooting in sunlight will then get annoying. You can blacken the tube with matt black paint, or a candle flame, but this comes off very quickly (it lasts long enough if you do it the night before a race). Normal gun bluing does not work on aluminium.
An adjustable rearsight enables you to change the brightness of the sight picture in different light conditions, without changing the zero. This can be very useful indeed.
Most people use a foresight element of about 3.2mm, but I have heard of between 2.8 and 3.6mm being used.
A blinder is useful if you are not strongly right-eye dominant (for right-hand shooters). These are usually home-made, of something like neoprene or a mouse mat. Most people like black; apparently target shooters prefer a light translucent blinder, and that is what I used to use (cut from a plastic milk carton). You can also get purpose-made blinders made of rubber from a gun shop - this is what I use now, and it is excellent, holding its shape very well while being comfortable on my back.
The one supplied by Anschütz is very hard to adjust and use. Better ones come from Larsen or Core Sport; a lot of people use home-made versions. You should use the same one (or type) all the time, as different types have different hook lengths.
The cuff needs to be tight enough to stay in the same place on the arm (at the top of the biceps/bottom of the deltoid), but loose enough to permit circulation. This can be a challenge, especially if you use the Anschütz one.
Anschütz make 3 different types of barrel: standard, stainless and hardened (nitride). The hardened barrel is somewhat more expensive but is supposedly much more durable than the others. Whether it shoots any straighter, who knows. They also do two external diameters - that on the new Fortner Sprint rifle looks like a straw sticking out of the filed-down receiver.
The two major makers are Anschütz and Larsen. Anschütz's are of a very hard wood, thoroughly adjustable and very well made. Larsen's are very amateurishly made and poorly finished, probably less strong (mine broke the first time I dropped it, only 6 months old); they are popular as they are quite cheap. There are many less commercial makers, and overall the best is probably the chap in Zinnwald who made most of the stocks used by the German men.
The Fortner rifle comes with a fixed 1.1mm rearsight and a rubber cup attached to it. You can cut down or remove the cup according to taste. Adjustable diopters are a great advantage as you can change the aperture without affecting the zero, according to the level of light, to keep the sight picture constant in varying light conditions.
Foresight elements used in biathlon are the standard Anschütz ring in a bar; Larsen's ring on a post; adjustable rings, on either bar or cross. Diameters are generally 2.9 to 3.6mm. I use an adjustable ring on a bar, made by Anschütz (Gehmann do similar ones), which has the advantage that I can set it at a slight cant - with the crossbar horizontal, the rifle is canted. These gadgets are extremely delicate and should not be touched when cleaning!