Ive been building shooting benches for over 40 years. (ALL) of our long range hunting is done from a bench or very good shooting tripod.
As for tripods, there are very few (good) ones. It all depends on what your needs are and how/where it will be used. Size and weight does
not also mean stability. For us, portability is very important. Also being able to adjust to steep/uneven terrain is very important. The lower
you make it the more stable it will be. We shoot sitting or from our knees due to that. If you want to shoot standing, you will need leg bracing if you
want it solid. 3 legs wont be as solid unless the single leg is in front. Thats even true with welded metal frames. My portable bench weighs just about 20 lb.
I start with an aluminum angle iorn rectangular shape frame made from 1 1/2x1/8" angle. Frame dimensions are about 20x32". The ends are mitered on a 45 deg.
They are welded with a small triangular shape aluminum gusset welded in each of the 4 corners. On those in each corner is welded a 1" e m t conduit coupling angled
slightly outward in both directions. The top itself is a single layer of 5/8" plywood 24x 36". The back is radiused in a rounded arc so as not to have sharp corners poking
the shooter. There are no cutouts for right/left shooters. The legs are e m t electrical conduit. We use 1" for the outer leg and 3/4" for the inner leg. Remember pipe
dimensions are inside dimension so 1" would have an o d of about 1 1/4". A 10' legnth of each size is enough for the 4 legs. We weld a block of aluminum about 3/4" square
on each of the outer legs about 4" from the bottom. Then drill and tap for a 5/16 pc of allthread with a 90 deg bend for leg adjustments. Of coarse the top end of the outer pipe
is threaded to screw into the couplings which were welded in the corners of the top. All the legs are stored on the bottom of the plywood top inside the frame when not in use.
The whole thing is about 3" high x 24 x 36" when not in use. Standard iorn pipe can be used in lieu of the aluminum but at considerable difference in weight. I have a sling attached
to the frame and sometimes it gets carried a mile or more from the vehicle.
However, there is a very good alternative to a shooting bench for field use. Check out the ULTIMATE TRIPOD, by MCFADDEN MACHINE CO, BLAIRSVILLE PA.
For a hunter, using guns as heavy as 20 lb. it has advantages over a bench. For one thing you can stand and shoot, and its easier to set up than a bench.
An animal cant run away from you regardless of direction when using this tripod. We bungee the gun down to eliminate most jump when shooting.
We also put the front swivel stud against the front rest block and put an angled bungee thru the trigger guard. It acts like a return to battery setup when you do that.