Thank you Reverend Hause for the extra info. Actually the 67mm fired Winchester case is not long for 2 1/2 inch chambers as per admissible lengths for them as permitted under CIP rules. Their pressure is below the recommended service pressure so should be usable as Eightbore concurs. A friend regularly does so with his British twenty without ill effects but I am hesitant. These are factory loads with one ounce of shot. But it is the max pressure that matters I presume.
Thanks again
All the best
SkeeterBD
