ORIGINAL: gixxer6bb
Today I was out siting my scope in for my mossberg 835 . I have a fully rifled barrel on it. I started shooting Brennekes to sight my scope in since they are cheap slugs. Once I got it sighted in I shot some leftover remington sluggers. I had bought a case of Remingtons new copper sabot slugs. I decided just to shoot one of these since they were so expensive. I figured I would use these for the coming deer season. I shot one and completley missed the target ( I was shooting a trash barrel with a target on it at 75 yards. ) So i figured I f'd something up so i reloaded one shot again and completley missed the target. At this point I stopped figured I maybe had wrong ammo. It was ammo for a fully rifled 12 gauge barrel which is what I have. Why would this shoot so completley different?
The problem could come from your having leaded up the bore shooting those cheapie lead slugs before you tried the good ones. But in all probability, it happened because the gun shoots the sabot bullets entirely differently than it does those lead slugs. If you intend to use those expensive sabot rounds for hunting, get a big target, set it up at 25 yards, and zero with those slugs. Then move out to 50, shoot to see where it hits, make corrections if necessary, then move to 75. You should not have to fire more than six or eight shots total to do this. But you MUST USE the load you are going to hunt with. There's no cheap way out of this problem.
Brennekes are real killers. If your gun shoots them well, use them for hunting. I would not use the Remington "sluggers", as they are pretty crappy loads.