Stan, I could modify my $10 yard sale jogging baby stroller in two ways.
-- Put a board or metal plank across the "step" in front of the cart..and fix it so butts could be supported there, while using only the ATV gun supports on the upper part of the cart. But I don't much like muzzles pointing towards me.
-- Or I could do same, put some 6" plastic 3" diameter tubes with wool inside on the plank and have them support the muzzles of the guns. Lot of home made strollers up here have them with simple plastic covered utility "U" supports to support the stock area...they are home-made in look and effective.
I actually started out using some old leather "dice cups" for the bottom support (I think I got those when I was living in Karachi in the 1970's - lots of gambling going on and I had a pool table in the house....finally had to limit the bets because fist-fights would break out).
But for some reason I don't like the muzzles of the guns resting on something, even plastic - I guess since that dint appeared in my 16 ga Reilly...I'm a little "gun-shy."
Both solutions would obviate the need for the second set of ATV gun racks... But there are a couple of holes in those ATV gun racks where ramrods fit perfectly...so...since I really don't need to carry the rod in the gun itself and have a bad experience with that...I'll leave it like it is for the moment.
