Im posting here as a last resort to see if anyone has an explanation for this odd behavior. I have a 308 scar 17 that has been a good reliable 1" gun for a long time. I recently added a sandman S, and my groups actually improved to a consistent .8-.9 which is great for a scar, but the first round cold shot is now exactly 5" to the left consistently. The second shot and all subsequent shots will be exactly on my zero until i pause long enough for everything to cool down. I suspect its something to do with the atmospheric change inside the can after the first shot, since it only ever takes 1 round to fix, and doesnt "walk in" to my zero over a series of shots.
I checked concentricity with a rod and bore scoped the can. I've rechecked torque on everything. I rarely ever clean, but i went ahead and did that just to see if it would change anything. The scope is a nightforce and i moved it to another rifle to make sure its not broken somehow. I also repeated this 5 times over the course of the day yesterday by just letting the gun sit a while, so its not a jumpy shooter problem.
At this point all i can do is ditch the can, but that's a bit of a bummer so hopefully there's something I'm not thinking of that's correctable. Thanks for any suggestions.
I checked concentricity with a rod and bore scoped the can. I've rechecked torque on everything. I rarely ever clean, but i went ahead and did that just to see if it would change anything. The scope is a nightforce and i moved it to another rifle to make sure its not broken somehow. I also repeated this 5 times over the course of the day yesterday by just letting the gun sit a while, so its not a jumpy shooter problem.
At this point all i can do is ditch the can, but that's a bit of a bummer so hopefully there's something I'm not thinking of that's correctable. Thanks for any suggestions.