sl-68 II

accuracy depends on paint/barrel match

you wont find a more durable gun on the market

dunno about barrel threads

upgradeability-its a pump theres not much needed done to it, make some regulation but thats about it.

here is my two cents. i want one

You need to order the barrels from Tippmann. They have their own threading. And it has to be thin so the slide can fit over it.