They're easier to shoot off a Bulls Bag, because you can slide the skinny forearm down into the slot in the bag.
a little off topic, but if you want a good cheap item to use for an attached rest for a 22 or thin stocked rifle.. try one of these....
as you can see from the picture, it attaches easily and is easily removed... gives a solid rest on about anything.. even a rustic fence post like pictured...
and there is all sorts of lengths they are available in...
The above item has a price tag of $2.50 from the Sportsman's WhoreHouse....
if ya can't figure out what it is, they are the pads that you slip on the canoe gunnels when you put a canoe on top of your car....
I've got some I have been using for 20 years around here....
work both well 'at the range' and ' out in the field' as shown.. this is a Marlin 917 with a factory synthetic stock in 17 HMR... this is from the first time I took Seafire Jr out with me and let him shoot this instead of his beloved 10/22/......