Do I need a taller front sight post? [Archive]

SoDak

03-21-09, 11:47

I've been trying to sight in my bushy dissipator(A2 upper) and the gun shoots high(about 3 or so inches at 50yds). I've got the front sight elevated to the point I can see daylight between the base of the sight tower and the adjustment disk of the sight post. Do I need to look at getting a taller front sight post or am I doing something weird with my sight alignment?

markm

03-21-09, 12:32

That's unusual. Is this a flat top? If I remember right, Bushmaster only uses standard FSBs... even on their flat tops. Is this a factory assembled upper?

More facts please....

SoDak

03-21-09, 12:40

Sure. This was a factory built rifle from 2005-2006(don't remember the exact year) using an A2 upper receiver. One other thing that I forgot to mention was that I was using the small aperture. Might that account for some of the problem?

warpigM-4

03-21-09, 13:43

I would not think so ,during training we always used the small aperture .Bushmaster makes a taller front sight post for use with flattops .I would try and compare your front sight post to another if possible.could be a bad post:confused:

ST911

03-21-09, 18:00

I've been trying to sight in my bushy dissipator(A2 upper) and the gun shoots high(about 3 or so inches at 50yds). I've got the front sight elevated to the point I can see daylight between the base of the sight tower and the adjustment disk of the sight post. Do I need to look at getting a taller front sight post or am I doing something weird with my sight alignment?

Sounds like you need a taller FSP. Have your ser# handy, call Bushmaster, and they'll send one out. In such a case, it should be gratis.

carbinero

03-21-09, 20:24

I had a CMMG (now returned with money back, thank goodness) which shot high like that, and the post was adjusted even higher than the protective wings. If that's the case with yours, a taller post won't help. In that case, perhaps a quality shop like SAW could fix it, or maybe it's a good candidate for a FSB shave and a rail. Hope it's the easy fix.

bkb0000

03-21-09, 20:32

waiwaiwait- i've seen guys with their elevation knobs twisted UP to "z" instead of bottomed out on "z"- is your knob bottomed out?

Gramps

03-21-09, 21:52

waiwaiwait- i've seen guys with their elevation knobs twisted UP to "z" instead of bottomed out on "z"- is your knob bottomed out?

IE: The rear sight? Sounds correct to me. I'd check that first too.

warpigM-4

03-21-09, 22:40

waiwaiwait- i've seen guys with their elevation knobs twisted UP to "z" instead of bottomed out on "z"- is your knob bottomed out?

bingo !!I did even think of that check that first

SoDak

03-22-09, 21:19

Dumb question time. What do you mean bottomed out at "z"? Is that the same as the 8/3 on the drumb? As far as I know the rear sight should have been bottomed out, but I can't confirm right now since I'll be away from home for a while. I never tinkered much with this gun, but it seems like it always had this elevation issue. If I had the money, I'd make the thing a flattop, stick a scope on it, and not have to deal with this, but I'm trying to save my money and make do with what I have. I might have to contact bushmaster and see about getting a taller front sight post.

scottryan

03-22-09, 21:50

If a bushmaster carry handle is being used, it is commercial height and a taller front sight post (military height) is not the solution to this problem.

bkb0000

03-22-09, 23:29

Dumb question time. What do you mean bottomed out at "z"? Is that the same as the 8/3 on the drumb? As far as I know the rear sight should have been bottomed out, but I can't confirm right now since I'll be away from home for a while. I never tinkered much with this gun, but it seems like it always had this elevation issue. If I had the money, I'd make the thing a flattop, stick a scope on it, and not have to deal with this, but I'm trying to save my money and make do with what I have. I might have to contact bushmaster and see about getting a taller front sight post.

you simply twist it all the way down, then back it up a few clicks to "z" to zero the weapon. generally when guys cant get their FSP high enough when trying to zero, it's because they have their knob twisted UP to "z" instead of down to "z"