What is the twist rate for a bushmaster

Pretty sure its 1:9 for the m4 type barrels

If u are zeroing irons at 50 and aren't grouping with 55gr ammo, I'd let a another ar owner give it a shot. Or you shoot a buddy's zeroed ar. If ur sights are on right, I'm thinking your sight picture is not consistent.  If you are experienced with AR irons then you could: do a quick bullet test / check crown, try different ammo, check barrel nut torque....

 

BTW, if using a2 rear I use 55g fmj and Improved battle sight zero for 50yds.  works great.

According to the website, their barrels are all either 1:9 or 1:8.  Both are intended for heavier bullets.

What type of BUIS are you using? Not sure if this has anything to do with the issue your having but I zeroed my Magpul sights and they were way off out the box, about 6 to 8" high.

I sympathise.  I tried to sight my M4gery in using the regular "carry handle" sights and the regular military instructions for the M4 --run base down to zero elevation, move up to thus-and-so markings, blah blah blah.

No go.

I finally broke down and put a scope on it.

No wonder they call them "BUIs"  --"Back-Up iron sights."



However, I have little love for the AR platform, so maybe there were unconscious negative factors operating.  I only bought one to see what all the fuss was about.  I especially dislike the way the front sight operates.  Shloppier than sh.  So is the rear sight.  Go ahead, wiggle them.  You'll see.

I had to get an extended front sight post to bring it anywhere near the zero required, since DPMS put an AR Rifle front sight on the carbine barrel.  Jeeze, didn't anyone learn basic geometry at DPMS? However, apparently a lot of mfrs do that, which is why they sell extended front sight posts in the first place.

I'm not signing this one so nobody will know who posted it.

Free zeroing in your scope at X-Ring for 2A members. Saves Ammo....

As long as they not busy.

I wasted 150 rounds of M1 carbine and was all over the paper. Never again. Laser Bore Sight it first!!!

Took advantage of your offer.  Thanks X-Ring!

Thanks for the input guys.  I'm planning to the range to re zero my AR, let me know if anyone wants to meet up. 

What is the twist rate for a bushmaster

can be anything.  Look at the top front of the barrel should be stamped on there......

Sorry to mention it guys I'm just zeroing in the iron sights.  I shoot 3 rounds then adjust from that.

I would suggest moving to a 5 shot pattern before adjusting.  Make sure you sandbag both the front and rear of the rifle. 

Other than this, it's tough to figure out what the issue is unless you have a specific plan you go with to sight in.  Also you have the manufacturer of the ammo listed?/bullet weight?

Free zeroing in your scope at X-Ring for 2A members. Saves Ammo....

As long as they not busy.

I wasted 150 rounds of M1 carbine and was all over the paper. Never again. Laser Bore Sight it first!!!

Haha i might have to take them up on that too.  Not having a spotting scope sucks.  When i first sighted in my ar, it took like 20 shots before i saw a single hole on my target.  Then when i went to check it, there were holes all over, but i couldn't see it with my shitty bino's. 

Haha i might have to take them up on that too.  Not having a spotting scope sucks.  When i first sighted in my ar, it took like 20 shots before i saw a single hole on my target.  Then when i went to check it, there were holes all over, but i couldn't see it with my shitty bino's. 

A decent spotting scope is key in sighting in, unless you a private range all to yourself where you can check the target after each string.  Even then, I would still use a spotting scope since I am WAY too lazy to walk back and forth that many times. 

You can always boresight by looking down the barrel as long as you have a stable base to support the upper.  I have a decent laser bore sighter, but my condo is so small that I just get ok results from it.  I could use the hallway, but my neighbors probably wouldn't like coming out of their unit with a laser on them and looking up and seeing the barrel of a gun. 

I do an initial bore sighting in my hallway. About 15 yards long.  Use a black circle.  Select a diameter that appears to fill 1/2 of the bore when you look through. Have the upper secured some way so it doesn't move. Then position your head in the same place the stock would be and adjust your sights to your prefferd hold, 6 o'clock, center, or what ever. Just make sure your sights are aligned and looking through the bore. You can do this with an optic sight as well. Don't cheat by moving your head around to line up the sights. Adjust the with your noggin in the same place it would be as if the stock was attached.  Next thing, go on the internet and print out a target circle, with an aiming black, about 5.5-6" in diameter, or get some shoot and see targets if you have a hard time seeing the hits. Also, put it on a brand new cardboard with no holes in it.  That will make this task a hundred times more easy.  Take it out to the range and place it at 50 yards. Crack open the back pin, open up the upper, and sight through the bore with the rifle well supported.  Center up the black in the bore, the sights should be pretty close already. If not make minor adjustments.
Find out and know how much 1 click value is worth on your sights. That means if your irons are 1MOA per click, that will translate to 1/2" at 50 yards, or 1" @ 100,  2" @200, etc.
At this point you should be on paper and you can find tune your sights with 3 round groups.

If you are not on paper something is wrong with the gun, sights, ammo, or that nut that is behind the butt stock may be loose.

I have never used a bore sighter, and have had great success using this method. As long as you can see down the bore, you should have no problem sighting in.

I used the bushnell laser bore device on a customers ar and took it to the range sunday. The gun was not even broken in. In fact it was her maiden voyage. All shots were dead on at 100 yards.

One thing i learned about the bushnell is you have to screw it all the way down. We checked this in a lathe and it was perfect at 50'

When i first got it i was rotating it in the bore and it was moving up and down 1" at 30'. It was my fault since i was stopping as soon as the laser went on.

At the shop we can only sight it in at 25' but we do it free so you get what you pay for? But so far everyone said we were close enough.