Bore sighting a 450 Bushmaster with brake installed.

[Texas Sheepdawg]

A while back, I tried boresighting my 450 Bushmaster with
a BSA collimator using the standard 45 cal bore spud and
Found it was too short due to the Izzy brake to be of
Any real help and the collimator was not tall enough.
To correct this, I purchased through Brownells, a collimator
Elevator part # 100-002-512 to address the height issue, but
Brownells quit carrying the extended 45 caliber bore stud.
I finally found these extended studs at Alley Supply in Nevada.
Here is the link.
http://www.alleysupply.com/default.asp?pc=sl
The spud is 18.50 plus 6 bucks shipping.
You can call and speak to Steve Alley and he can fix you up.
Yeah the collimator elevator is pricey, but you can use it
For any AR or other high scope mount and is adjustable to
Extremely high mounted scopes. It works great with my
BSA collimator kit. You can also get other caliber long bore
Spuds through Alley Supply.

[BD1]

Maybe I'm old fashioned, but I just pull the bolt and carrier and look down the barrel at the target
BD

[Jim in Houston]

Ditto on pulling the bolt and looking down the bore to align the barrel with the bull. Your eye naturally goes to the center of the bore. Then I lift my head and look through the scope, and dial in the scope till the cross hairs are on the bull. Then recheck with the bore and adjust the scope as necessary. You can do this off a sand bag rest. With the 450, if you are on at 50 yards, you will be on the paper at 100 yds and need just a little scope adjustment for the longer range.

I do use a laser in one of those bullet shaped collets to align my 5.56 in the home defense mode, setting the reflex sight and laser sight with the red dot coming out of the barrel so that I am on target at the length of the longest unobstructed space (a hallway in my case) in my house. This is about 50 feet, so I will be shooting a little low at closer ranges.

These laser alignment thingies don't work outdoors - the laser is not bright enough to make it to the target, unless you do it at night.

[Texas Sheepdawg]

My eyes get blurry looking down a barrel bore but that's just me.
But on my mini 14, 10/22 and a few other rifles, view down the
Bore is obstructed by the receiver. And I agree, the laser might
Work in an indoor range, but not an outdoor range and I'm not
gonna pay for a range when I have a 150 yard rifle range,
40 yard pistol range and a 60 yard archery range on my property.

[wildcatter]

I myself am too lazy or is it I just love the act of burning cordite, but I just sight in at 25yds and then retire to longer ranges, of say 100 to 400yds for the rest of it. Using a ballistics calculator will tell you how high to have the bullet strike, at 25yds, and be able to hit a target your follow-up ranges. The 25yd sight and using a ballistics calculator, will even put you on the paper much farther ranges than I normally use, final tweaking will be necessary, at your chosen final range. This all takes less than a half dozen rounds, if a tape measure is also used.

Why a tape measure? Using a ballistics calculator will tell you how high the 25yd group needs to be, to be able to hit paper, at let's say 400yds. Accurately measuring the initial 25yd group, you'll need to adjust the group to the chosen spot on the target, to hit paper at the longer range. You must accurately (with-in an eighth of an in) measure. Remember, our scopes, for the most part, have 1/4MOA clicks, which at 25yds, requires 4x the clicks we use at 100yds, which means you'll need 16 clicks to move the bullet strike one inch, at 25yds.

Having said all this, I just scored a super deal on a laser ($10), installed in a 223 dummy cartridge (http://www.opticsbestbuy.com/SIGHTMARK- ... 39001.html). As the various laser companies do not have one of these in a 450b yet. I plan to fill a 450b case with Devcon and then ream a 223 chamber into the bottom of the case, all to be able to use the 223 laser in the 450b. I hope the laser beam, will travel the center of the bore and to be able to see the laser dot at 25yds, if these two requirements happen, then the 25yd sight in wont take any rounds at all, to be able to hit paper at the longer ranges..t

[Jim in Houston]

My range won't allow anything above a 22 at 25 yds, so I have to go to the fifty yard for the initial sight in.

I agree you could use the ballistic tables to set up the scope in advance, but if you are on at 50, you are on the paper at 100 and can make the adjustments ad hoc.

Of course, if your only option is to sight in at 25 and you don't have longer distances available, then you will have to make table adjustments for what you expect to get at 100 yards or longer.

[BillytheKid]

My brother has a 45/70 laser bore sight that we used. It didn't fit all the way into the chamber, but well enough that it got us on paper at 25 yards, and we sighted in from there.

Bill

[BD1]

"I myself am too lazy or is it I just love the act of burning cordite,"

Hey Wildcatter, if you're down to pulling surplus .303 to keep your self in .450B's I'll try and send out a WC297 "care package"

BD

[MOUNTIN DU]

my izzy comes off so easily that i just set the bore sighter without it on... then replaced it

[wildcatter]

My range won't allow anything above a 22 at 25 yds, so I have to go to the fifty yard for the initial sight in.

I agree you could use the ballistic tables to set up the scope in advance, but if you are on at 50, you are on the paper at 100 and can make the adjustments ad hoc.

Of course, if your only option is to sight in at 25 and you don't have longer distances available, then you will have to make table adjustments for what you expect to get at 100 yards or longer.

James, maybe you cold shoot at 25yds on the 50yd range. If it's outside, I often use a Realty Sign for target backers. They just push into the ground. Just thinking here..t