This is of course exactly what I was waiting for for my Stalingrad diorama since Matt showed us the first pictures of the sculpt. Admittedly, I was unfamiliar with this weapon:
The PTRD-41 (Shortened from Russian, ProtivoTankovoye Ruzhyo Degtyaryova) was an anti-tank rifle produced and used from early 1941 by the Soviet Red Army during World War II. It was a single-shot weapon which fired a 14.5x114mm round. Although unable to penetrate the frontal armor of German tanks, it could penetrate the thinner sides of early-war German tanks as well as thinly armored self-propelled guns. The 14.5 mm armor-piercing bullet had a muzzle velocity of 1012 m/s. It could penetrate an armor plate up to 35 to 40mm(40mm with tungsten ammunition) thick at a distance of 100 meters at 0 degrees. During the initial invasion, and indeed through-out the war, most German tanks had side armor thinner than 40mm (PzKpfw I & II: 13-20mm, III & IV series: 30mm, PzKpfw V Panther (combat debut mid-1943): 40-50mm) which meant that the PTRD teams need to be close to very close sometimes point blank distances to have a chance of penetrating the sides of these tanks however due to the high velocity and small nature of the round it had a very high chance of shattering or utterly failing against armor it should have penetrated which was aggravated if the target was not at a perpendicular angle.
http://en.wikipedia.org/wiki/PTRD
"Russian Use of the Antitank Rifle" from Intelligence Bulletin
Translation of a set of seven directions for Russian antitank riflemen, from the Intelligence Bulletin, November 1942.
In destroying German tanks, Russian antitank riflemen follow a set of directions, which are given here in condensed form as a matter of information:
"1. Show daring. Let the enemy tanks come within 200 yards or closer. The best range is 100 to 200 yards. Don't let the enemy fire lead you to open your own fire too soon.
"2. The antitank rifle can fire 8 to 10 rounds per minute, if the gunner and his assistant use teamwork. The gunner opens and closes the breech, aims, and fires; the assistant, lying on his right, cleans and oils the shell and places it in the chamber.
"3. Remember that for a distance of as much as 400 yards, the effect of the wind need not be considered.
"4. Remember the deflection correction for the movement of the tank. At a speed of 22.5 miles per hour, a lead of 1 yard is required for every 100 yards of range.
"5. Aim for the rear of the turret—the gunner and ammunition are there. If you hit the ammunition, you can blow up the tank.
"6. Fire at the center of the rear half of the tank—the motor and the fuel containers are there. If you hit either one, you will put the tank out of action.
"7. A well-camouflaged gun crew can put any tank out of action with well-aimed shots, and can block a road to a whole column of tanks."
http://www.lonesentry.com/articles/atrifle/index.html