Key Highlights

  • The optimised Western Queen resource is 3.92Mt at 3.1 g/t gold for 393,100oz, a 19% grade increase and 9% fewer ounces than the June 2026 estimate.
  • A high-grade zone at Western Queen Central holds 129kt at 11.6 g/t gold for 48,500oz, almost entirely in the Indicated category.
  • The updated scoping study outlines a production target of 1.2Mt at 3.2 g/t for 125koz over almost four years, with ore toll treated at Kirkalocka.
  • Study outputs include free cash flow of $133M, a pre-tax NPV of $86M at an 8% discount rate, an IRR of 45% and pre-development capital of about $8M.

Rumble Resources Limited (ASX:RTR) has re-estimated the Western Queen gold and tungsten resource in Western Australia using tighter wireframes shaped around underground mine design, lifting overall grade 19% to 3.1 g/t gold. The optimised estimate stands at 3.92Mt at 3.1 g/t gold for 393,100oz, and it underpins an updated scoping study that outlines a production target of 1.2Mt at 3.2 g/t for 125koz of contained gold. The project is about 90km northwest of Mount Magnet.

Tighter Wireframes Raise Resource Grade

The June 2026 estimate was 5.13Mt at 2.6 g/t gold for 433,600oz. For the new estimate, lode wireframes were built at a 1.0 g/t cut-off to remove low-grade peripheral mineralisation, and block sizes were changed from 5m x 1m x 1m to 5m x 1m x 5m to match the orientation of the mineralisation. No additional drilling data was added. Contained gold fell 9% while grade rose 19%.

Indicated resources total 1.87Mt at 3.7 g/t gold for 223,800oz. At Western Queen South and Central, Indicated grade increased 27% with a 1% reduction in ounces. Against the July 2025 estimate, total ounces are 6% higher and Indicated ounces 51% higher. The estimate draws on 17,255m of diamond drilling completed between October 2025 and April 2026, was prepared by Ashmore Advisory under the JORC Code 2012, and sits within mining leases M59/208 and M59/45.

High-Grade Zone Below the Central Pit

The drilling defined a high-grade zone at Western Queen Central measuring roughly 250m by 100m. It contains 129kt at 11.6 g/t gold for 48,500oz, almost entirely Indicated, directly down-plunge from the existing open pit and historical underground workings. Earlier models assumed barren pegmatites had diluted much of this area, but the latest diamond drilling and structural modelling showed the pegmatites displace far less gold than previously modelled. Historical production at Western Queen Central was 660kt at 8.9 g/t for 190,000oz.

Updated Scoping Study Parameters

The study assumes uphole stoping with paste fill at a 1.7 g/t cut-off, with 80% of the production target by mass in the Indicated category and 20% Inferred. The schedule runs 52 months from decline start. First development ore comes at month seven, initial stopes at month eleven and full production of about 30kt a month at month fourteen. Only about 30% of the current resource is included in the target.

Ore would be trucked about 185km to Gylden Resources' Kirkalocka plant, which has a nominal 2.0Mtpa capacity. The toll milling agreement runs four years and 11 months from the first parcel, with campaigns of 75,000 tonnes. The study assumes 92% gold recovery, within the 90-94% range indicated by historical production and testwork. Rumble retains 100% of its share of recovered gold.

The study reports gross revenue of $657M, operating costs of $429M and capital costs of $95M at a gold price of A$5,714/oz, producing free cash flow of $133M, a pre-tax NPV of $86M and an IRR of 45%. All-in sustaining costs are A$4,390/oz. Pre-development capital is about $8M, underground development capital is $70M and infrastructure capital is $11M. The estimates carry an accuracy of plus or minus 30%.

Tungsten is not in the study's economics. The project holds a tungsten resource of 4.31Mt at 0.31% WO3 for 13,200t, and a feasibility study now under way will incorporate it alongside work with Gylden on a recovery circuit at Kirkalocka. Most key permits are received, with only the Mining Development and Closure Proposal still to be received.

Where Western Queen Stands

Rumble now reports a smaller, higher-grade resource of 393,100oz at 3.1 g/t, with 223,800oz Indicated and a 48,500oz zone at 11.6 g/t at Western Queen Central. Those figures feed a 125koz production target processed under a five-year toll milling agreement, with study economics stated to a plus or minus 30% accuracy.