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Sounds like a reasonable cleaning period to me

If your getting that much unburnt powder it could be worth adding some extra weight to the bolt-I have found it really helps.
Swapping the spring guide around just doesn't seem to cut it with...

Unfortunately I'm not near mine to look. Photos are probably needed

In a gervarm there is a block that does "float" as its how they stop them going auto.

Do you have a take down or a solid one?