Hold on there, before we start running to a gun smith.

Let's go over the basics, before we start spending money.
It's a semi Auto. They are famous for havingdifferent points of impact from the first shot to the second and third etc.

Try this:

Clean the gun with a copper solvent and make sure it is clean. I'm not talking about looking down the barrel (put a flashlight in the open action) and saying "it looks good to me" clean. I mean pushing patch after patch of copper solvent cleaner through it until it comes out as clean as it went in. If it was my gun and I bought it used, I would then push some JB bore paste (Brownell's)through it and make sure it was clean. This will also remove some of the copper catching burrs in the barrel that exist in just about every factoryinstalled gun barrel out there.

Now, when you are sure the gun is clean put up several targets. Load the gun with one bullet only and let the action slide fully forward with all the force from the spring. Make sure the gun is pointed in a safe direction, just in case somehow you get a slam fire. I have never seen this happen with a bar, but ,,,, safety first. This will get as close as possible to the same position the bolt will be in as when the gun cycles for a second shot.

Now at one of the targets fire this round to the best of your ability. After you see where that shot went, open the bolt and hand cycle it with another round just like you loaded the first round. Fire the second round and see where that one goes. I'm guessing it will be pretty close to the first one.

Now load the gun magazine with as many as it will take. Cycle the bolt hard by hand like you did the last 2 times and fire at the first target again. You should now have a 3 shot group here.

Now, ignore that first target and fire the rest of the rounds at a second target. I will bet that the rest of the rounds will group very well. The reason for this is when the bolt cycles from the bullet firing, it has a tendency to seat the round in the chamber much harder than when you just let the bolt close on a round manually. This will often move the bullet further up in the chamber, closer to the lands, and affect the point of impact.

Try this experiment and see if the different methods of bolt closure to battery don't affect the point of impact.

Once you have that figured out, what you need to do is see which ammo will work best in that gun. Make sure that you clean the gun thoroughly when ever you switch brands of ammo and even bullet weights. Remember, when you clean the gun it will now be cooled down again and will shoot to a different POI than a warm gun. Also most guns typically throw a flyer to a different POI on the first shot after cleaning. I usually firea fouling shot after cleaning.

It's a 30-06, so a 165 grain bullet has the best BC and sectional density, and theoretically should fly the best. I don't know what the twist is in your gun, so it may actually like 180's better.

Also understand that not many people break a gun in the proper way, which is of utmost importance, even with a fine gun like the BAR. When breaking a gun in, you should at least run a patch and a bronze brush after each round for the first ten rounds. Then do same after each3 round volley, letting the gun cool between rounds. After 20 rounds this way, Clean again thoroughly and then do a thorough cleaning with the JB Bore paste. I think you will be surprised at the accuracy that can be attained from off the shelf guns, that are often shot 20 or 30 times by the first owner, and get copper fouled and are difficult to clean and people give up on them, and they end up on the second hand shelf, where I do most of my shopping!

Any rough spot along that barrel on one side or another, will collect copper and powder fouling in the burrs along the lands. This copper will build up enough to prevent the bullet from obturating and sealing the gas behind it. This can squeeeze the bullet out of shape, and you really don't want that as the bullet's concentricity is what allows it to push through the atmosphere and fly straight. The tiniest bit of out of round can put that bullet 3" off at 100 yards, let alone several hundred yards.

It sounds like a lot of work, and it is. But once you break in a barrel correctly it will clean easier and you will get more accurate rounds between cleanings, saving you time in the long run.

Have fun.