Grouse are not hard to kill, just hard to hit.
If you can shatter a clay pigeon at 35 yards you can kill a grouse with the same shot size. You want a big full pattern.
My BIL uses his 12 gauge with 1 1\4 oz pheasant loads. He blows them away. Not much left to eat.

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Some people wait a lifetime to meet their favorite hunting and shooting buddy. Mine calls me dad
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