A couple of Duke #650 footholds around the cam and stand might give them a nice pinch and solve the problem...I'm kidding of course! Sucks you have to deal with garbage like that.
Definitely common to see this. Things like powder type and amount, primer type, even neck tension will affect velocity. Then you have the projectile construction itself that affects BC which in turn affects flight and so on. Definitely sight the rifle in to the cartridge you will be using. I...