I don't know where you shoot, but there are portable shooting "benches" & tables you can buy from Midway or Brownells that you can set up anywhere.
I use one for my handgun testing normally in an old stone quarry. I have used it for rifles in the past, but I'm lucky in living 20 miles from a state-owned rifle range with concrete tables, so that's where I do most rifle work nowdays.
You do genuinely need a solid platform that provides repeatable results.
If you're not solidly braced in learning, you can't reliably evaluate which parts of your target results were your fault & which parts were the gun's fault.
In zeroing the gun, it has to be steady, you have to be steady.
In working on technique, YOU have to be consistent, and you can't be if you & the gun are both wandering on target.
If you plan to seriously pursue shooting, you need to understand it'll cost money.
Spend some to get yourself a GOOD shooting platform.
I use a strong plastic-topped portable shooting table with folding legs from Brownells that isn't quite as stable as a concrete bench, but works adequately if all feet are firmly planted on the ground.
I also use a standard resin patio-type chair with a tall back, and I use a shooting rest for handguns set on the table.
Table & chair were both fairly cheap, both lightweight & easy to transport.
There are dedicated rifle shooting rests you can also buy from Brownells, or you can dummy something up yourself to rest the fore-end on.
Key is to make the table stable, make yourself stable, rest the rifle's fore-end on something, and eliminate as much movement as possible while you're lining up your sights and pulling the trigger.
Get this done before you waste ammunition in trying to figure out why groups are large & where the gun shoots.
Edited to add that you can find the MTM Predator Shooting Table I use on Amazon for $75.
Weighs 15 pounds, folds flat.
Looks like Brownells doesn't carry it.
Last edited by DPris; August 13, 2013 at 04:39 PM.