While doing some general research, I jotted down a summary of the main ATR I could find that were used during WW2. This came out as follows:
- Lahti L-39: (Finland) 20mm semi-auto, 50kg, MV 800m/s
Type 97: (Japan) 20mm semi-auto, 52kg, MV 790m/s
Solothurn S18/100: (NEI) 20mm semi-auto, 50kg, MV 735m/s
Boys 0.55” ATR: (British Commonwealth, Belgium) 14mm bolt-action, 16kg, MV 884m/s
PTRD – 41: (Soviet Union) 14.5mm bolt-action, 17kg, MV 1114m/s [also PTRS semi-auto version 20kg]
Panzerbuchse PZB-39: (Germany) 7.9mm bolt-action, 11.6kg, MV 1210m/s
WZ-35: (Poland) 7.9mm bolt-action, 10kg, MV 1275m/s
The thing I found most interesting though was the comparison of muzzle velocities. Both light ATR are within 65m/s of each other, as are the three heavy ARTR. However there is a whopping 230m/s difference between the British Boys ATR and the Soviet PTRD-41, despite only a 1kg difference in weight. This probably explains why the Boys was considered such a poor weapon by many. Its anti-tank capability compared to the Soviet model must have been woeful. You got all the weight for none of the performance.
Well, after considering this I came up with the following house rules to reflect these differences in size, weight and performance:
Heavy ATR (20mm) [AT 3, HE 1] require a crew of 5 and cannot move if the crew falls below 3 personnel, cannot move and fire
Medium ATR (14mm) [AT 2, HE 1] require a crew of 2+ and, if the crew falls to 1 man, lose 1 pip from each movement dice and cannot move and fire. PTRD-41 & PTRS can re-roll one of their armour penetration dice.
Light ATR (7.9mm) [AT 2, HE 1] can be operated by a single man at no detriment. Can move and fire just like a rifle.
So, what do people think? Happy to take questions and criticisms.