450Bushmaster.net

I took my new 450 Bushmaster out to a range and attempted to zero it with a knock-off EOTech sight. No luck, it kept hitting way left and and the battery compartment kept coming open.

I bought a set of UTG iron sights (for now). I went to the range again. Same thing happened, I kept hitting to the left.

I sent the upper back to Bushmaster and they say it is fine.

I went to the range again. I hit two rounds about 2 inches left of aim at 10 yards and then my rifle stopped ejecting cartridges. I have a new ejector and hope to have it installed this week.

I must be doing something wrong, but I can't imagine what it is. Any ideas? Suggestions?

My first guess would be that the front sight was not centered correctly, but these don't come with a front sight so I'm kinda at a loss.

Let me think on it and I'm sure other will chime in with their ideas soon.

Just a shot in the dark, Maybe take a look at the gas block? Is it installed correctly? Sounds like the begining of a previous problem.

Where did you get the knock off eotech from(there are good knock offs and bad ones)? I had the same thing happen to me so I dumped the knock off for a real 557. I guess it can't be that if it is doing it with the BUIS. Can we get some info on the rifle and what modifications it has? What did it do in specific when it stopped ejecting? What mag are you using? Which UTG sight and is it a knock off too?

The rifle has no modifications to it other than to add a sling. It is straight out of the box.

The gas block was adjusted when it went back to Bushmaster, sxo i assume that is correct.

I am using a generic AR-15 (.223) 30 round magazine with the blue follower inserted so that i have a 9 round magaizne.

I feel confident that I will get the feeding thing striahgt. It is the bullet placement that is making me pull my hair out.

The UTG sights are are real UTG sight from purchased through Amazon.com.

I had the initial problem of having the scope dead on at one range and then at another range it was 3 inches to the left. This may sound goofy -- but I traced the problem to how I was positioning the rifle at the bench. One range I was fairly comfortable, with the recoil coming straight back and the other range had very high benches that were causing me to grip the rifle differently and torque it to the upper left during recoil. How the grip is grasped on an AR also effects where the bullet goes. We also have the effect of a scope that is 2.5 inches above the bore -- not the usual 1 to 1 1/2 inches. Not having the rifle absolutely level for each shot can cause some horizontal displacement. I have since used a level on the Picatinny rail when shooting off the bench.

Is this a carbine? If your front sight is mounted to the gas block, your gas block could be moving. I learned not so long ago, that if you remove one of the gas block set screws(at the bottom of the gas block) and inspect with a good flashlight, you can tell if it is lined up with the set screw hole. If it is off to one side, it could cause the problem with zero, and ejection that you describe. It was recommended by bushmaster to use some lock-tite when replacing the set screws, which makes me wonder why they don't use it from the factory .

Two interesting possibilities. I will investigate when I can get back to the range.

Perhaps the gas block & sight issue should be added to the knowledge base.