What Caliber Donor Rifle for Converting to 5mm GT?
Choosing the right donor rifle for a 5mm GT conversion is crucial for a successful and cost-effective build. The ideal starting point isn't just about caliber, but also about action type, barrel length, and overall rifle features. Let's break down the factors to consider and some popular choices.
Understanding the 5mm GT Cartridge
Before diving into donor rifles, it's important to understand the 5mm GT (Gunwerks Technology) cartridge itself. It's a relatively new, high-performance cartridge designed for long-range precision shooting. This means your donor rifle needs to be robust enough to handle the pressures and recoil generated. The cartridge's relatively small diameter also influences barrel considerations.
Key Factors in Donor Rifle Selection
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Action Type: A bolt-action rifle is the only practical option for a 5mm GT conversion. The precision and control required for this cartridge necessitate a reliable and robust bolt action. Consider actions known for their accuracy and ability to withstand high pressures.
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Caliber: Several calibers offer suitable starting points for a 5mm GT re-barrel. The closest commercially available options often require less extensive modifications to the chamber and bolt face. However, a skilled gunsmith can re-chamber virtually any suitable bolt action.
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Barrel Length: A longer barrel (24-28 inches) is generally preferred for the 5mm GT to maximize velocity and accuracy. While shorter barrels are possible, they’ll compromise some ballistic performance. Choose a donor rifle with a barrel length that aligns with your desired performance characteristics.
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Magazine Capacity: Consider the magazine capacity of your chosen donor rifle. While you might need to modify the magazine to accommodate the 5mm GT's slightly different cartridge length, starting with a rifle that has a detachable magazine makes the conversion process easier.
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Overall Rifle Condition: A rifle in good condition is essential. Examine the action for wear and tear, and inspect the stock for cracks or damage. A sound foundation is crucial for a safe and accurate conversion.
Popular Donor Rifle Calibers
Several calibers make excellent donor rifles for a 5mm GT conversion, each with its own advantages and disadvantages:
1. 6mm Creedmoor: This cartridge's popularity and widespread availability make it an attractive option. The 6mm Creedmoor's case is relatively close in size to the 5mm GT, reducing the amount of work required during the re-barreling and chambering process.
2. 6.5 Creedmoor: While a bit larger, the 6.5 Creedmoor’s case provides a substantial foundation that's readily available on the used market. It requires more significant modification, but the abundance of rifles makes it a potentially cost-effective option.
3. .260 Remington: This cartridge offers a similar case size to the 6.5 Creedmoor. It's another strong contender in terms of availability, making it an excellent donor candidate.
4. .243 Winchester: While smaller, it’s a strong option, especially if finding a donor in 6mm is proving difficult. This would necessitate more machining for the chamber.
Important Considerations:
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Gunsmith Expertise: A 5mm GT conversion is a project best left to a skilled and experienced gunsmith familiar with wildcat cartridges. The process involves precision machining and requires specialized knowledge to ensure safety and accuracy.
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Cost: Factor in the costs associated with the donor rifle, the re-barreling process, the new barrel, any necessary modifications to the bolt face and magazine, and the gunsmith's labor.
By carefully considering these factors and consulting with a qualified gunsmith, you can choose a donor rifle that's well-suited for a successful 5mm GT conversion, resulting in a custom rifle tailored to your specific long-range shooting needs. Remember that safety should always be the top priority in any firearm modification project.
