Well per the Novels and what nought
Machine guns range from 50 cal to 30 millimeter, though interestingly IIRC most Mech based ones seem to be 50 cal and ones on vehicles are 20mm, though support units seem to have 50 cals as well, thier is a 15mm HMG in use by infantry, called a Spanner
AC-2s in general range from 20 to 50mm, though 30mm is some what more common, the only RAC-2 I know of was referenced as being 40mm
AC-5s range from 40 to 120mm, 50 to 80mm being the most common range (50 being the most common around), though three systems have been listed as being above 100mm
AC-10s Range from 75 to 100mm, Clans seem to favor 75 with the IS favoring 80mm, with a few 100mm in the mix
AC-20s range from 100 to 203mm, with 120mm being the most common by far.
Autocannon shells are of coarse describe as HEAP with a "tip" of DU, as such I view them as a variation of the
Mk 211 Raufoss, the novel describes them being fired as high speed streams and chewing through the armor. Most auto cannons are largely are burst firing machine guns.
Gauss rifles have few references on size one such IIRC was 100mm, their very commonly depicted as either canon ball or melon shaped, made from Nickel Iron, though their are a few references to a DU core, unlike Autocannons Muzzle velocity is fairly common, with the majority being hyper sonic (about 70-75% of the totals, ~45 vs ~15), mass weight is the same as the game (for both standard and heavy versions). Novel depictions often entail smashing of armor, ripping off limbs in not unknown.
Lasers are for me a bit contentious, Im actually in a argument right now on another forum on this, basically theirs largely enough arguments to go any number of ways I think which makes this a bit frustrating. Basically one can find examples of out right vaporization of armor, as well as melting of the armor, explosive vaporization (remove some armor that allows the rest to fly off), and a mix of explosive and melting. So how much energy this takes is up for grabs...
Their are examples of armor falling off in semi molten heaps, small streams of molten armor, as well as examples of armor being explosively removed.
Missiles are slightly smaller versions of modern AT weapons, though perhaps with a bit more yield than one might expect.
As for computers I would not know how B-tech compares but they do have ridiculously high data storage capacity (even in 3025 "mainframes" had the ability of 100 billion books). Though I do not think B-tech strictly uses a smart mainframe and dumb terminals, though I suppose it might be common for "public terminals".
Small tablets are common that do much of what every one uses smart phones for (sans the phone bit), data searches, games music & data editing.
Theirs holographic gaming consoles, heck B-tech can make a pore mans holodeck, they have 3d displays, smell o vision and tactile feed back...
