Back Stop

[Technician1002]

Having water stand upright is the problem.. If using a cheap container, it gets holes.

I wrote a 45* and a tub of water beneath.

No holes unless you shoot low.

OTOH Place the water tub into a hole in the ground and shoot away!

BoyntonStu

Not very handy for testing long barrels unless you have a cliff in your back yard.

In testing with jawbreakers, impacts on water do chip them. I'm not sure glass marbles will not break at high speed.

[geardog32]

maybe some thick wet sponges?

[UKSGC]

How about a straw bale or two? Hard as hell and cheap.

[spudtyrrant]

How about a straw bale or two? Hard as hell and cheap.

i second that i have used a single straw bale to catch 12 guage slugs before the should catch a high velocity marble no problem

[Ragnarok]

I'm not sure glass marbles will not break at high speed.

If anyone recalls the result of HEAL and glass marbles from the video, it put them through a foot of water, then reduced them into shards on the (admittedly concrete) backstop behind.
Of course, given HEAL can push marbles to near the practical maximum of pneumatic cannons, that's probably more speed than we're talking about here.

Do we have any idea what kind of energy these marbles have at 100 yards? That would make figuring out a backstop easier.

[DinerKid]

well i just prototyped a system with a peice of plywood at a 45 and i am about to go try that out so i will let you know how that works

[boyntonstu]

What I would try is a few thicknesses of carpet with a plywood backing that swings away over a tub of water.

I would set it at an angle so that when the momentum pushes the carpet away like a ballistic pendulum the marble energy is absorbed and it will fall into water.