Does it have to be wood? Home Depot sells 10’ and 12’ PVC rails. They also sell rounded off 4x4s, I can’t remember what they’re called but two sides are rounded, that would work for rails.[/QUOTE]
I strongly suggest NOT using PVC for rails. While teaching horses to lose respect for the jumps, the PVC can get fragile with time, shatter when knocked against. Had it happen with my horse at a Pony Club practice. I yelled WHOA, she stopped dead on landing, which prevented her getting cut up on ALL THOSE SHARP pieces around her feet! I had the kid just hold her still, while I ran over and picked up pieces before she could move. What a mess that was! I hauled my own WOOD rails to practice after. But using those PVC rails, she started hanging a leg, testing to see if the rails were solid or that “knock down stuff” as a terrible habit! She wouldn’t even try to jump, just bulled thru the PVC rails.
You might hire a local Handyman type to make up some rails for you, if you are not handy with sawing things yourself. We just took the corners off the pressure treated 4"x4"s and made them into 8-sided rails. Husband used the table saw and the portable hand saw both, making up rails for the Pony Club to practice with.
I bet with using a local Handyman, Carpenter, he could make quite a few rails for you in only a couple hours of work. No shipping expenses if you buy the wood and bring it home to get the work done there. Price of his labor wouldn’t be that much for just the couple hours or so. You can’t PUSH the wood thru the saw, so they do take a little time to cut, but not hours and hours, unless you want a LOT of rails made up.
We used the 10ft lengths, easier to move, good width to avoid runouts. 12ft are just too heavy for much moving, 8ft rails are too narrow, horses try to avoid them. With the pressure treated rails, let them dry flat, before painting or coloring them. We used the Olympic stain base coat, which is what they add the color too, rails were white for us. It was a latex and dried FAST, with easy cleanup. I was able to get 2-3 coats on in one day, a big time saver. Those rails STILL look real nice after 10+ years outside. I do put them inside the barn storage over winter.