
Availability: In Stock
The MEC Sizemaster is a cast-iron single-stage shotshell reloading press built for hunters and competitive shooters who want to load ammunition on their own terms. Whether you're prepping 12, 20, 28 gauge, or .410 bore shells, this all-in-one press handles the core operations—resizing, priming, powder charging, and wadding—without the complexity of progressive loaders. It's the kind of press that rewards patience with precision, giving you control over every round you send downrange.
The heart of the Sizemaster is its Power Ring collet resizer, which brings fired brass back to factory specifications reliably, round after round. That matters if you're going to shoot the same shells repeatedly or if you simply want consistency you can trust. The E-Z Prime automatic primer feed system keeps the workflow moving without fumbling—a small convenience that adds up over a large batch. Both high and low base shotshell heads are supported, so you're not locked into a single type of hull.
Built to last in cast iron, the Sizemaster comes ready to work: one charge bar and three powder bushings get you started across a range of load combinations. The press adjusts to handle 3 shells at a time, making it practical for both serious reloaders stocking up and shooters who simply want to stretch their ammunition budget without industrial throughput demands.
| Product | MEC Sizemaster Shotshell Reloading Press (Model 812020) |
| Construction | Cast iron |
| Type | Single-stage press |
| Gauges Supported | 12, 20, 28 gauge and .410 bore |
| Primer Feed | E-Z Prime automatic (not compatible with .410 bore) |
| Resizing System | Power Ring collet resizer |
| Shell Head Compatibility | High and low base |
| Processing Capacity | 3 shells (adjustable) |
| Included Accessories | 1 charge bar, 3 powder bushings |
No. While the press handles .410 bore shells, the .410 is not compatible with the E-Z Prime automatic primer feed. You would need to hand-prime .410 rounds on this press.
The Sizemaster reloads 12, 20, 28 gauge and .410 bore shotshells. The automatic primer feed works with 12, 20, and 28 gauge only.
The press comes with one charge bar and three powder bushings, giving you flexibility to adjust powder charges across different load recipes without purchasing additional components.
Yes. The Power Ring collet resizer is designed to handle both high and low base shotshell heads, whether the base is brass or steel.


SKU: 144599986 • Width: 17.1in • Height: 9.3in • Depth: 22.7in • Weight: 19.45oz



Availability: In Stock
The MEC Sizemaster is a cast-iron single-stage shotshell reloading press built for hunters and competitive shooters who want to load ammunition on their own terms. Whether you're prepping 12, 20, 28 gauge, or .410 bore shells, this all-in-one press handles the core operations—resizing, priming, powder charging, and wadding—without the complexity of progressive loaders. It's the kind of press that rewards patience with precision, giving you control over every round you send downrange.
The heart of the Sizemaster is its Power Ring collet resizer, which brings fired brass back to factory specifications reliably, round after round. That matters if you're going to shoot the same shells repeatedly or if you simply want consistency you can trust. The E-Z Prime automatic primer feed system keeps the workflow moving without fumbling—a small convenience that adds up over a large batch. Both high and low base shotshell heads are supported, so you're not locked into a single type of hull.
Built to last in cast iron, the Sizemaster comes ready to work: one charge bar and three powder bushings get you started across a range of load combinations. The press adjusts to handle 3 shells at a time, making it practical for both serious reloaders stocking up and shooters who simply want to stretch their ammunition budget without industrial throughput demands.
| Product | MEC Sizemaster Shotshell Reloading Press (Model 812020) |
| Construction | Cast iron |
| Type | Single-stage press |
| Gauges Supported | 12, 20, 28 gauge and .410 bore |
| Primer Feed | E-Z Prime automatic (not compatible with .410 bore) |
| Resizing System | Power Ring collet resizer |
| Shell Head Compatibility | High and low base |
| Processing Capacity | 3 shells (adjustable) |
| Included Accessories | 1 charge bar, 3 powder bushings |
No. While the press handles .410 bore shells, the .410 is not compatible with the E-Z Prime automatic primer feed. You would need to hand-prime .410 rounds on this press.
The Sizemaster reloads 12, 20, 28 gauge and .410 bore shotshells. The automatic primer feed works with 12, 20, and 28 gauge only.
The press comes with one charge bar and three powder bushings, giving you flexibility to adjust powder charges across different load recipes without purchasing additional components.
Yes. The Power Ring collet resizer is designed to handle both high and low base shotshell heads, whether the base is brass or steel.
SKU: 144599986 • Width: 17.1in • Height: 9.3in • Depth: 22.7in • Weight: 19.45oz

