I've never removed or installed a gas block so pardon my ignorance.

I've read the FAQ here and I think I can handle removing the old shaved block.

My questions are:

1.  Do I just eyeball the alignment of the YHM block and then adjust it at the shooting range if the windage is too far off?  Or is there a better way?

2.  Will the YHM leave any marks, grooves or other unsightly spots exposed on the barrel after I install it?  If so, how do I fix them or hide them or do I leave them?

3.  Are there any differences between Bushmasters and what is shown in the FAQ?

4.  Is the $20 difference between the YHM and the BMAS sight that clamps over the shaved gas block worth the difference in efffort to install?  Does the clamp-on sight work well?

Thanks in advance for your help and advice.

I just built my first AR and took of the FSB and replaced with a YHM-9394 "Front Flip Sight Tower"
and I just eyeballed it and was only 4 - 5 clicks off. Its not hard. The new FSB covers the old taper pin holes and just looks cool.

It is my understanding that most of the B.M.A.S. things Bushmaster sells are made by YHM.
If you look at the part number on the bushmaster web site some start with YHM-something.

                                 Invisiblesoul

eyeball and align the dimple on the lower side of the bbl. with the hole in the fsb.


i will say that the bushmaster gasblocks and front sights are a pain to get off if not struck hard enough since they are parked over after install.

Did you use any type of bonding agent to put the sight on, TheInvisibleSoul? YHM's manual recommends that you do it on two sights specifically, but I am not sure if it needs doing on any of their others.

Quoted: 1.  Do I just eyeball the alignment of the YHM block and then adjust it at the shooting range if the windage is too far off?  Or is there a better way?

Eyeball it.  Set your rear windage to mechanical zero.  Go zero the weapon, adjust the FSB to get it really close, then adjust rear windage to lock it down tight.

2.  Will the YHM leave any marks, grooves or other unsightly spots exposed on the barrel after I install it?

No.

3.  Are there any differences between Bushmasters and what is shown in the FAQ?

Bushy FSB's are the hardest to get off.  Just gotta support the barrel well, and pop them hard with a good hammer.

4.  Is the $20 difference between the YHM and the BMAS sight that clamps over the shaved gas block worth the difference in efffort to install?  Does the clamp-on sight work well?

It is a matter of opinion.  I like flip ups... mounted to the barrel.  PRI is the best, and the YHM is ok too.  I have a YHM on mine.... due to cost.  I wimped out.  I dont regret it.... because it is just a BUIS after all.    But damn those PRI's are cool.

If the install is a problem for you YHM usually offers free installation on most of their stuff. Then you know it's sighted in and works right when you get it back.

Quoted: If the install is a problem for you YHM usually offers free installation on most of their stuff. Then you know it's sighted in and works right when you get it back.

They do?  Wow, that's a good deal.  They even zero it, and shoot it???  That is a lot of time and expense.... I guess not too many people take them up on that.

Quoted: Quoted: If the install is a problem for you YHM usually offers free installation on most of their stuff. Then you know it's sighted in and works right when you get it back. They do?  Wow, that's a good deal.  They even zero it, and shoot it???  That is a lot of time and expense.... I guess not too many people take them up on that.

When I had them install a free-float tube for me, they made sure to remind me to include the bolt/carrier so they could shoot it.  

Don't know if they zero sights after installing a FSB.