dzavracky wrote:
I just held the barrel in one hand and wound the spring in with my other. The spring came flying out on the first attempt

so I’m sure there has to be a better way
David, normally I only do this with very small spring barrels.
The safest way to hold a barrel is to set up a vise on a work bench with two wood blocks that have V shaped cut outs that can clamp and hold the barrel while you feed in the spring using two hands to control it.
You need to be careful not to apply too much pressure to the barrel though, so as not to distort it.
My method is a little different though, and you probably shouldn't try it until you are a bit more confident and practiced at installing springs, or unless you have steel underpants lol, because I sit on the floor with my legs spread and hold the barrel between my feet.
This gives good surface area grip on the barrel, and allows me to work straight above the barrel giving me the ability to use the full strength of my hands and arms to feed the spring in and control it.
And with the barrel basically between your legs, believe me, it's good incentive to take your time and concentrate on what you're doing, and to not let go
