For a new variable power scope on a AR flat top receiver, do you pre-sight in (to get close) at home before going to the range and do you use a boresighter or other method at home?
Scope user manual suggested separating upper and lower, steadying the upper, remove the BCG and charging handle and then sighting the target thru the bore, and then adjusting the crosshairs to the target center.   

For a new variable power scope on a AR flat top receiver, do you pre-sight in (to get close) at home before going to the range and do you use a boresighter or other method at home?
Scope user manual suggested separating upper and lower, steadying the upper, remove the BCG and charging handle and then sighting the target thru the bore, and then adjusting the crosshairs to the target center.

you got it

Boresighting is a free and completely practical way to get on-paper before you ever shoot a round. 

For a new variable power scope on a AR flat top receiver, do you pre-sight in (to get close) at home before going to the range and do you use a boresighter or other method at home?
Scope user manual suggested separating upper and lower, steadying the upper, remove the BCG and charging handle and then sighting the target thru the bore, and then adjusting the crosshairs to the target center.

i have a laser boresighter
if you like borrow, send a pm

you got it

I've been fortunate to have rifles that allow me to look through the bore without interference and getting the sights on paper at 50 yards. It takes a little practice but once you get the hang of it, it works. Just sight it in at the range. You don't need to pre-sight the rifle at home.

I use these for sight ins






Fraser Boresight








Eliraz Israeli surplus

I use a laserlyte boresighter at home first. Super easy.  I'd buy it again for the time / ammo / frame damage it saves at the range.

Thanks guys for all the feedback.  The scope was already centered by the factory out of the box and came in quickly with the method suggested in the user manual.   Last week I tried sighting in at the range and could barely hit paper at 50 and 100 yards, even using the irons was more accurate than the scope(LOL).
 I had previously tried to sight in with an older SL boresighter at home and had to make a lot of elevation and some windage adjustments to get the reticle close to the laser.   For me, lessons learned, do not overly adjust the scope from factory centering before going to the range.  Luckily the manual also describes how to reset elevation and windage back to factory centering.   This boresighter has worked well with little adjustments for red dots before.   Going to the range next week to try again. 
That Fraser looks like a big bucks piece of equipment.

Uncle Sam pays about $2K a piece for them.
The IDF version in the 80s were $1500.

On the surplus market they go for about $300-$500 if you can find them.

Laserlyte and a target at 25 yards or so.  You can adjust elevation later depending on how you want your zero set, but this gets the windage dialed in.

Boresighting is a free and completely practical way to get on-paper before you ever shoot a round.

Agreed. There's some math involved but you can boresight even at a close distance. I did my AR in my condo and was on paper right away at 50 yards when I went to koko head.

All you need is a ruler and piece of paper.

Agreed. There's some math involved but you can boresight even at a close distance. I did my AR in my condo and was on paper right away at 50 yards when I went to koko head.

All you need is a ruler and piece of paper.

S197 how does your process work (with the math)?

Really, just look through the bbl and make the crosshairs match.
Then pick a spot on the berm at 100 yds and take a shot.
See where the dirt flies and make rough adjustment.
Then shoot paper.

Just look though the bore.  it's free.  Place your eye far away from the bore, line up the edge of the chamber, center of the bore, then the center of the target, than match crosshairs to that.  You should be on paper at 50.

I have an orange dot on my wall in my garage that is there for just this reason. I look through the barrel and get it on the orange dot then look through my scope and move the crosshairs until they are on the orange dot. Gets me on paper and rather close to POA in most cases. Otherwise I do what Oldfart does. See his post above.

I use a laser boresighter.  It installs in the muzzle of the rifle with O-rings to make up the difference in bore size.  I measure the bore to scope offset and set the POI that many inches below the POA. 

This is enough for me to get on paper at the range.

I use a laser boresighter.  It installs in the muzzle of the rifle with O-rings to make up the difference in bore size.  I measure the bore to scope offset and set the POI that many inches below the POA. 

This is enough for me to get on paper at the range.

I found this one to be the best for me, both for ease of use and universal fit.  No buying multiple lasers or arbors for various calibers.  The magnet attaches to the muzzle (which ought to be perpendicular to the bore axis). 

The green laser is more visible at longer ranges and bright light, but the red laser saves money.

http://www.amazon.com/exec/obidos/ASIN/B007WQJCWC/?tag=2ahawaii-20

i have used laser bore sighter.  works well.

also did the look thru the bore way too, my friend adjusted the scope elevation and windage as I looked through so i wouldn't have to go back and forth looking and adjusting
went really quick
hit paper fist shot

I used the look thru the bore method after the range fiasco and it adjusted quickly to the test target on a hallway door about 27' away.   The only positive of that range trip was my reloads all fired, cycled the bolt and ejected properly with no high pressure indicators on cases.  My first 300 BLKOUT reloads.
 I have an old SL-100 laser sighter, but sighting in thru the bore is faster and don't eat up batteries.  Mahalo guys for all your replies.