Approximately 20 years ago I shot a 28ga Parker Reproductions for 3 or 4 seasons as my grouse gun & I used the Winchester 1oz of 7 1/2 load almost exclusively. Despite what has been written about the 1oz 28ga being an inefficient load, the Winchester load gave good results on the pattern board & seemed to kill grouse well.
As previously mentioned, those loads were slow @ something <1100 fps but 20 yds was a long shot in the cover I was hunting & the grouse didn't seem to notice the loads were 150 fps slower than normal. I don't remember recoil being severe under hunting conditions either & the Parker Repo had the standard skeleton steel buttplate.
I don't disagree that 3/4oz or possibly the old Federal 7/8oz load makes more sense in a 28ga but I thought those Winchester 1oz loads worked very well.
