What model of moderator was it?
Do you know what actually happened, blockage, pressure spike, dent or previous fracture etc, does he reload?
the mod is a sonic and we think it was down to corrosion
Corrosion would not do that. More likely blockage, badwelding on the mod, or if its a mod you can take apart its not been reassembled properly.
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How old's the mod & how many rounds has it had through it?
I hope your friend was ok, must have been quite a bang!
Along with others I'm sure, I would like to know all the details as to exact cause, since so many of us now use moddy's.
It does look like it gave way on a seam to me.
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