I'm new to varmit rifles but not to big game rifles. This .204 of mine has about 50 rounds down it and all it does is copper foul. I've been running some jb and copper fouling solvent down it but it still contiues. So here's my ?: When the the copper fouling stop or does it? I know this thing is shooting around 3750 fps but man I hope the fouling goes away.