Big Bore Challenger .357 Big Bore — Planning a CF Bottle Conversion

[Grunt64]

I’m still running the factory aluminum tube on my early‑run .357 Challenger Big Bore, but I’m mapping out a full CF bottle conversion. Nothing is installed yet — this is all planning and layout work for now — but I wanted to share the reasoning and see if any other Challenger owners have gone down this road.

Why I’m considering the CF bottle setup:

• Increased usable pressure range
• More air volume for tuning and heavier slugs
• Flatter shot curve compared to the factory tube
• Better balance for tripod/bipod shooting
• Long‑term parts support is getting thin for these older Big Bores, so I’m future‑proofing the platform

Why it’s still on paper:

• Waiting on the correct adapter and a proper bottle support
• I won’t clamp anything directly to carbon fiber
• I want the geometry, clearances, and balance point sorted before I start turning wrenches
• I plan to document the entire process so other Challenger owners have a clean reference

Below is the rifle as it sits now, along with a render of the direction I’m heading.If anyone here has done the CF bottle conversion on a Challenger Big Bore, I’d appreciate any notes on what worked and what didn’t.