Defender Tungsten Project Drilling Update

4 August 2026

GREAT WESTERN MINING CORPORATION PLC

("Great Western", "GWM" or the "Company")

Defender Tungsten Project Drilling Update

Addison Mining Services Engaged as Competent Person Ahead of Imminent Drilling

Great Western Mining Corporation PLC (AIM: GWMO / Euronext Growth: 8GW / OTCQB: GWMOF), a strategic minerals exploration and development company, is pleased to provide an update on the upcoming drilling programme at the Defender Tungsten Project ("Defender" or the "Project") in Mineral County, Nevada, USA.

HIGHLIGHTS

·    Drilling at Defender is expected to commence in the next two weeks, with all preparatory fieldwork now complete and drill pads constructed.

·    Addison Mining Services ("Addison") has been engaged as the independent Competent Person for the development of a maiden JORC Mineral Resource Estimate ("MRE") at Defender.

·    Lewis Harvey, Director Exploration Services & Principal Geologist of Addison, will be on site throughout the entire drilling programme to oversee data capture and quality control, streamlining the resource evaluation process and ensuring an efficient path to resource definition in Q4 2026.

·    Assay results from the drilling programme are expected through September and October 2026, in addition to results from the bulk sample metallurgical work conducted in Q2 2026.

Great Western CEO, Ed Loye, commented: "I am delighted to confirm that drilling at Defender is about to get under way. The preparatory work completed over recent months, including geophysics, geological mapping, trenching and drill pad construction, has given us invaluable information and the team is eager to build on this through drilling.

"The appointment of Addison as Competent Person is a significant step for the programme. I will be arriving on site this week to oversee the start of drilling and will be joined by Lewis Harvey of Addison, who will remain on site throughout the entire programme to ensure that data capture and quality control are embedded in the process from day one, rather than applied retrospectively. This is a more rigorous approach that we expect will result in a smoother, faster path to resource definition.

"The schedule for delivering a maiden MRE in Q4 2026 remains firmly on track. Looking ahead, investors can expect a steady flow of news over the coming months, with drilling assay results due through September and October alongside results from our Q2 bulk sample metallurgical programme. This will be a busy and high-impact period for the Company."

DETAILS

As previously announced, the Company has completed a comprehensive programme of preparatory fieldwork at Defender, including a detailed gravity geophysical survey, geological mapping and grab sampling across the mineralised corridor, and four machine-cut trenches at locations between the Defender, Pine Crow and Widowmaker Mines. Drill pad locations have been finalised and access roads between the Dough God Mine and Defender Mine have been prepared.

The Company has now engaged Addison Mining Services as the independent Competent Person responsible for development of the maiden MRE.  Addison is a geological and mining consultancy providing high-quality consulting and contractor services to the global minerals industry.  Its expertise spans a wide range of mineral projects including base and precious metals, industrial minerals and energy resources. Addison specialises in mineral resource and reserve estimation, exploration programme design and implementation, procedural audits and best practice operating procedure development, Competent Persons studies and reporting to JORC2012 and NI43-101 standards.

Lewis Harvey, Director Exploration Services & Principal Geologist of Addison, will be present on site throughout the drilling programme to oversee core logging, sampling protocols, data capture and quality assurance. This integrated approach is designed to ensure that all geological data meets the standards required for JORC-compliant resource estimation, reducing the risk of delays or data gaps during the resource evaluation phase.

Drilling is expected to commence in the first half of August.  Assay results from the programme are anticipated through September and October 2026. These will be reported alongside results from the 750 kg representative metallurgical bulk sample previously sent to Eriez in Pennsylvania for flotation test work, as reported on 1 June 2026.

The Company remains fully funded for its 2026 exploration programme and on target to deliver a maiden MRE by the end of Q4 2026.

ENDS

For further information visit www.greatwesternmining.com or contact:

Notes

Great Western Mining Corporation PLC (AIM: GWMO / Euronext Growth: 8GW / OTCQB: GWMOF) is an exploration and development company focused on strategic minerals across several 100%-owned claim groups in Mineral County, Nevada, a highly prospective and mining-friendly jurisdiction. The Company has an increasing strategic emphasis on tungsten as a critical mineral, while continuing to advance its Huntoon Copper Project, which hosts a JORC-compliant resource of 4.3 Mt at 0.45% Cu with further porphyry upside. It also maintains exposure to gold and silver through exploration and tailings reprocessing opportunities, alongside evaluating farm-out and joint venture options to unlock wider portfolio value.

Forward Looking Statements

This announcement contains forward looking statements relating to the plans, activities and expectations of Great Western Mining Corporation PLC. Such statements include, but are not limited to, those concerning planned exploration programmes, anticipated timelines and potential mineral resource outcomes. Forward looking statements are typically identified by words such as "plan", "expect", "anticipate", "intend", "may", "could", "potential" or similar expressions.

These statements are based on current expectations and assumptions and involve risks and uncertainties that could cause actual results to differ materially. Factors include geological risk, exploration and drilling results, permitting and regulatory approvals, funding availability, operational challenges, commodity price movements and general market conditions. No assurance can be given that any forward looking statements will prove to be accurate, and shareholders are cautioned not to place undue reliance on them.