I highly recommend Tony Williams' site.
For those interested not only in firearms, but the whole topic of 20th and 21st century military ammunition. Tony has the most extensive private collection of ammunition in the UK, and probably in the world. And his collection of ballistic data matches his collection of the actual items.
Not only can you get the data on the relative performance of a British Boys AT rifle vs. a Soviet PTRS …
… you can also see the cartridges for yourself! (In this case: 13.9mm x 99B vs. 14.5mm x 114.)
And if you wonder how the Poles thought that a .30 cal AT rifle could ever be effective, well check out the cartridge of the 7.92mm x 107 round of the Maroszek rifle compared to the 12.7mm x 99 round of the Browning .50cal, and ask yourself just how fast you think such a little bullet could go!
It's a treasure of information for anyone interested in post-black-powder era military weapons.
-Mark
(aka: Mk 1)
