Best way to test bullet stability from muzzle to 10 yards?

[Scollins]

Since I don't want any baffle strikes on my new suppressor (Gemtech HVT, don't have it, soon) I wanted to see about a testing method to determine bullet stability at various distances. I don't have a high speed camera, so that option is out. I could maybe rent one somewhere.

The barrel is a 1x8" (hope to have it soon from Randall) and the current projectile is the 240 grain SMK. I know this combination should produce fine results, I'm just worried about the distance from the muzzle crown to about 3 feet. If these suckers are wobbling significantly at all in this range, then I need to rethink my choice of bullets.

So, what is a decent way to determine bullet stability at these distances? I was thinkink a very stiff piece of cardboard (to resist muzzle blast) might work. Any other ideas?