Can't remember if it's model 197 or 195 but Crosman produced a very nice bulk-fill adaptor intended primarily for the model 160. Here's a pic.
Problem is, in practice it does work very well. The gas tube is just too small to accept a good charge and this is with a model 160 with a double powerlet gas tube. This is why MAC-1 produces the bulk-fill extension tube for the model 160. With the longer gas tube, bulk fill works just fine.
On a model 150.... Forget about it. For the same reason that the model 115-116 bulk fill models are not good. You need to bump up at least to the size of the model 112, before bulk fill starts making any sense. Even then, it takes good technique to make it work.