I 've tried to find 80 to 100 lb hay bails.It seems all the farmers in my area roll the huge bales now.
Will a thick layer of cardboard work?The soil is so rocky where I shoot that if I miss it ruins my field points.Thanks for any help.

Go to a local sporting good shop and buy a bow and arrow target.

I have the target.I made a stand out of PCV pipe and hung the "Tough Bag" from that.The target is about 2' in width and 2' in height.
I just started practicing from a longer distance now and don't hit the target every single time.

I have horses so I have lots of round bales. I just took one of the older 6ft round bales and turned it side ways to use as a backstop. Works great. I also have paper targets on a few bales. The arrow only goes in about half way if shooting at the side. If you shoot at the center you could loose the arrow in there lol.
stryker777

I sponsor an archery club at high school here and get a lot of students who haven't had much or any experience; so a backstop for arrows missing the target is essential. I have set up an old hot tub lid, which catches a lot of errant shots. The bows the kids are using are mostly fairly gentle, so the lid open at full width stops the arrows. Speedier arrows go through but there is a good catchment area behind and they are always found lying on the grass. But if the lid is used at 'folded in half' position, even the fast arrows stop. Works good and the price was right.

Use the wifes car, I use straw rectangle bales.

You could hang 2 or 3 pieces of old carpet behind your target. Dont stretch it tight, just let it hang.
I use an old round picknick table. Bout 5' dia I think & hang my homemade bag targets from this. I covered the table with foam insulation about 3" thick with carpet over it.

No disrespect intended but if you sometimes miss a 2x2 bag you should probably move up a little and get more proficient at closer distances. Be patient and don't be in too big of a hurry to shoot at 40, 60, and 100 yards. It's fun for sure but more fun when you hit what you're aiming at. Start at 20 and go back 5 yards at a time. The farther back you go the more critical everything becomes. Form flaws are accentuated and a bow shooting great at 20 may not be at 40. Have fun.

Two guys I shoot with don't use anything as a backstop. If you miss, you're probably out an arrow. Another one uses a big piece of plywood...it stops arrows, but isn't the nicest to them. Don't use this unless you shoot carbons for sure.

I personally...shoot in front of my pond bank. I have been known to launch a few over the hill of it, but almost all of them catch it and stop. It's a great backstop.

Hay bales should work, good luck finding one.

Nothing. Just a target or a deer.