Not having chronographed a 20bore, but having done quite a bit with the .69, I'd assume you would get approx. 1,300fps with 80gr. 3F GOEX. My .69 ran 1,240 with 82gr. 3F with it's heavier ball of 484gr. In that rifle, I had to go to 165gr. 2F to get 1,500fps. The reason for the switch is that more than 80gr. 3F shredded the patches, but they'd take up to 200gr. of 2F and still be usable.
: I once shot a 5 shot group of 1 1/2" at 50yd. offhand using the same patch over and over, with a 125gr. 2F load. That amount of powder gave me 1,300fps. Yeah - it took another 40gr. to get an extra 200fps. in my 30" barrel. If I remember correctly, 110gr. 2F gave me the same vel. as 80gr. 3F. My vel with 82gr.2F was only 1,000fps. Switching to 82gr. 3F gained 240fps. Velocity comes slowly in a 60" twist 14 bore. Bro's first 46", .75 Bess got 1,080fps with 82gr. 2F, a bit more vel than my 30", 14 bore. The longer barrels do help with velocity.
: The last time I shot the rifle, I had reduced the hunting load to 125gr. of 2F. AT that, it gave fairly light recoil, mostly due to it's styling. The butt plate was a full 2" and a bit wide.
Daryl
