Sportco's "start-up" machinery was apparently from the Hendon annexe of SAF Lithgowicon.

Sportco made SMLE barrels in several calibres; .22/.303 (Sprinter) .25/.303, .270/.303 among them. The exterior profiles are "remarkably" similar to a standard-weight .303 barrel.

They even fitted them with "surplus" SMLE sights, though most seem to have a "commercial" style front-sight "ramp" along with the issue rear sight. Production at Sportco often ran to four barrels per hour, not bad for a small shop using traditional cut-rifling methods.

The other interesting "line" involved the "sporterising" of Martini Cadet rifles. Sportco won a tender for 40,000 of these, back in the good-old-days when governments actually sold small arms in bulk to the public. About half were then on-sold to Golden State Arms in the US.

More historical stuff about Sportco here: http://www.sportco.org.au/pdf/history01.pdf

Meanwhile, Lithgow had been in the "sporter" game for quite a while, ultimately producing a range of "borrowed" designs as well as things like the SMLE-based .22 Hornet repeater, single-shot .410 shotgun and, rarest of them all, a repeater chambered for the .310 Cadet cartridge.

The mighty Omark target rifle was originally a Sportco design and product, until acquired by Winchester, via their "Omark" subsidiary. Winchester had previously contracted Sportco to produce a range of .22 RF rifles for the US market in parallel to Sportco's small but growing sales there. The big red "W" sold these "badge-engineered" rifles for less than the "original" product and the rest is history.

The Sportco foray into shotguns is another interesting story.