Thanks everyone. I bought one from Cabelas, looks to be identical to the Herters.
I may build a couple as well. Tripod configuration possibly with Sched 80 pipe legs with an over-sleeve tight fitting pipe which will be attached to the 3/4" plywood top. They will be heavier and less portable than the Herters style but may well be stronger/more solid. Something to play with.
Weight dosent necessarily correlate with sturdy.
A 1/2" plywood top can be as sturdy as a 3/4" plywood top, depending upon what the top is fastened to.
A piece of plywood, preferably exterior grade, 24" wide and 32" long is adequate size for even the larger bench rest type guns. Just round the corners slightly so they dont jab you.
Both left and right hand shooters can use it.
Then use light weight 1 1/4" aluminum angle to create a rectangle about 4" smaller than the plywood.
Fasten the plywood on with screws up from the aluminum angle.
In each of the 4 corners weld a small triangular shape piece of 1/4" thick aluminum as a gusset which helps secure it from wobbel and provides a base for attaching the legs.
As for legs, go to an electrical supply house, not a box store, and get one 10 foot length of both 1" and 1 1/4" of heavy wall aluminum conduit. Remember, all pipe is measured ID not OD, so the 1" will slide inside of the 1 1/4".
Also get 4 1 and 1/4" couplings, which will be welded on a slight angle outward to the triangular pieces in each corner of the frame.
Cut the 10' pieces in equal lenghts, and thread one end of each of the 1 and 1/4" pieces which become the fixed outer portion of the leg and screw into the welded in place couplings.
About 6" up from the bottom of the outer section, weld an aluminum 5/16" nut, or make one from just a square piece and weld that on to the leg. Tap the nut making threads, and use some 5/16" all thread bent for a handle for the adjustment.
Or you can use a bolt with a piece welded on for a handle as well.
The 1" part can be slid inside and tightened at whatever length is required for terrain conditions.
At Home Depot you can buy rubber crutch bottom pieces, and the can be used on the bottom piece to prevent dirt build up from entering the leg. You can also just pinch the bottom closed and weld it.
The legs will screw on and off, and can be stored on the bottom of the plywood top.
My bench as described is about 30 years old, and weighs just a bit over 20 pounds.
I have a sling attached to one side, which makes for easy carrying.