i would not bother with a bridgport or bridgeport clone (BP, since that's a lot of typing) for what you're planning. they're huge and will sit idle 99+% of the time and since they're a bitch to move unless you are a rigger in your spare time, that means it's in the way a lot. if you stick it in a corner as is often done, you'll lose some of the working envelope that was the entire point of getting BP
wear is pretty important to discuss here briefly. there is a phenomenon where the wear is centered near the center of the table as the ways grind against each other. on a large maching like a bridgeport, whose table is 42 something inches wide (working surface, the handles and such stick out more), even if you're making 12" long parts you end up with all the wear in the center 24 inches or so, and the outer edges are nearly pristine. if you try to traverse the entire table length with any accuracy, say fly cutting something so it's flat, you end up with a U shape because the table is moving nearer and farther from the cutter as the wear in the ways does what it does.
i'll guess that 80% of the bridgeport style machines spend most of their life working in that center section of the travel and at the price point you're going to be happy with, since you're a bit of a penny pincher, there will be wear. will it affect your pistolas? i don't know.
as mentioned there are desktop machines capable of what you're after for reasonable prices. if you buy new, get something with an R8 taper in the spindle. it's by far the most common taper these days, which makes certain tooling decisions easier.
there are a number of mid size knee mills out there as well
clausing is probably the most famous
Wells Index made some too, though the spindle taper is usually not R8. i hear the manufacturer will regrind the quill to R8 for a few hundred dollars (a freaking deal) if you manage to find one.
Grizzly makes offers a chinese clone of the clausing
i think the ubiquitous
Rong Fu mill drill is probably your best bet. repainted and relabled by freaking everyone, here is
grizzly's version. double the price and paint it white you can have one that says Jet on it. they come up for varying degrees of silly asking prices on craigslist fairly often.
as kindof an oddball suggestion, since you're making murican guns you shold use vintage murkia to make it:
http://sfbay.craigslist.org/sfc/tls/5413168530.html
it has an MT2 taper which isn't as common but already has 3/16", 5/16", 1/4", and 1/2" collets, you can get a lot of tooling with a 1/2" shank.
if you have 220v single phase available, powering any tool won't be that hard. rotary phase converters have already been mentioned, and there are Variable Frequency Drives (VFD) which is a solid state way to do the same thing and they're usually cheaper. find an unused 3phase electric motor though, and you can build your own rotary converter (because you need projects, before you get to your projects right?)
