The main concern you must be aware of for such tours is that you have to get details before booking it. The laws regarding such weapon are very strict here in Russia, and such shooting is allowed to take place only in shooting clubs and polygons. Quite popular tour you've linked is all about shooting in specific place (shooting club), with no outdoor experience. Yes, you can take photos, but they wouldn't be shocking. From other side, you'll get shooting experience from a real weapon.
I suggest you to search shooting clubs directly (Central Shooting Club in Moscow, Baltic Shooting Club in Saint Petersburg), without travel agencies - you'll save your money and wouldn't be limited in time or number of bullets. Even more, you can choose some other weapon, for example, in BSC:
First WW weapons
Maxim machine-gun

Mosin-Nagant rifle

Second WW weapons
PPSh-41 (Shpagin's submachine gun)
Dozens of AK modifications, even handle machine gun:

One bullet (especially for old weapons) is up to 80 RUR, so for 50 USD you can book 20 bullets and a taxi from your hotel in Saint Petersburg. Prices in Moscow can be greater up to 20% more.
Another tour you've linked, as I think, is the similar to previous one, as they say that you'll fire from 50 meter distance, which is a standard distance for shooting clubs.
All other offers are about shooting from copies of weapons, which are pneumatic, so this can be done only for photos :) I suggest you to google the KMB(Курс молодого бойца, recruit training)-course in Moscow, it's fun, you'll take many photos, eat a real soldier's food, learn how to disassemble AKM, but shooting is made from a copy, as I said already. The price for tour I've linked is 2400 RUR, which is near 50 USD.
In Saint Petersburg you can find a popular tour for UAZ driving and AKM shooting - you'll learn how to drive a real military car:
http://spb.daroo.ru/images/data/10879_1_0910uaz1.png
More options can be found here (there are some tours for Stalin's Military Line, knife fight and even tank driving tour), but they are more expensive than you can spend :) (starting from 6400 RUR, which is near 120 USD). Tank driving near Moscow can be done too.