A detail that has always eluded me is the blast bag. Back "in the day", it was a detail that wasn't even considered by the kit manufacturers. Now of course, with the current "new tooling" kits, almost anything that shoots has a bag molded on to the barrel, although they come at the cost of loosing those elevating barrels (a feature I really miss from the old molds)
Even when one considers the purchase of an aftermarket brass barrel kit that comes complete with a resin bag, you still loose the ability to elevate those guns, since the castings are rigid. I considered cutting the upper portion of one of these bag castings to allow for upward travel of the barrel, but that would mean destroying a large amount of the bag itself.
I have attempted to scratch build a bag (using clay,masking tape etc), but in 1/700, they come out looking like a blob, a distressing thought, when considering all that expensive brass detail surrounding the turret.
It occurs to me that a different media is called for, one that possibly retains some flexability, but will still look "wrinkled and saggy" (kind of like Clint Eastwood in his latest movie)
Has anyone done any experimenting with this ?

I have had some success with Kleenex. You will need to fill the void first and the apply a small piece of Kleenex and then dampen it with thinned white glue.

Hope this helps.
Kenny

I generally prefer my guns flat on the deck, but back in the day I wold use white putty and mold it into hole with fingers and shape it, then take a toothpick and sculpt in some wrinkles