View Full Version : Chronograph alignment using Laser Bore Sighter

El Paso Mark
01-18-2010, 05:28 PM
Greetings all. I’m sure this has been thought of/discussed before, but I just thought of it a few months ago- Using a Laser Bore Sighter to aid in Chronograph set up & alignment.

I have my first chronograph (CED M2) and I must admit I’m rather clumsy/unskilled when it comes to setting it up and aligning it. I thought- “There’s got to be a better way” and I gave it a bit of thought. Then it struck me- How about one of those laser bore sighters? I did a little research on them at the Midway site and found one from Aimshot/Osprey that claimed “Visible to 25 yards outdoors.” I figured I only needed to see it out to 15 – 18 feet or so (5 – 6 yards) so it sounded like just the thing. I didn’t get around to ordering one until about 2 weeks ago, and didn’t test it out until today. It works.

I took a couple used targets and with binder clips and tape attached them to the chronograph “Arms” and sensor body. To get proper alignment I cut a hole (.223 is about right) in the first (Front) paper so the laser would, when properly aligned, go through the hole and paint on the back paper. If alignment was off in any way (Up, down, cocked, left, right) I could see the laser on the front paper and make adjustments to get it through the hole. When the laser shot through the hole and painted on the rear I knew everything was aligned properly.

Here are a few pictures from the “Driveway test” I did today in full sun about 11:00. If the weather cooperates I’m going to the range tomorrow to test ammo and will try this in a “Real world environment.” Meanwhile:

Bore sighter set up on the reloading bench (Simulating rifle in rest on bench {Had to add the ammo boxes to get enough height})-


Chronograph set up on tripod-


Front paper showing laser and hole (Look between the shadowed “V” of the arms between the 3 & 4)-


Rear paper showing laser paint (Middle of “V” to the 4 o’clock from the 3)-


Maybe not the slickest set up (Using old targets) so I’ll leave it to someone else to make refinements (Thought about maybe using a plexiglass front). The laser is a .223 diode module and you have to buy inserts for different calibers. Alas, they don’t make sleeves for the “Custom” benchrest calibers (6 class, 6.5, etc.) but I’m thinking until they do if you cut off the head (Base) of an old piece of brass to use as a sleeve it should work (Will have to try that).

Will post an update and pictures from the range session.



01-18-2010, 05:51 PM
Good Idea,

I usually just look throught the bore to get the rifle aimed on target, then look along the left and right side of the barrel to make sure I am in the (middle) of the sky screens. At the same time it's important for the screens to be on the same plane as the bore of the rifle. At 100 yards our target is downhill quite a bit so we have to tilt the screens downhill as well. A second person, one at the bench, and one at the Tripod makes this an easy job. With only one person it can be a bit of the runaround (back and forth from the bench). I can see how this lazer Idea would work well. Do you intend on inserting the lazer in the bore of the rifle being tested? That would require a lazer for every caliber wouldn't it? For us Benchrest shooters and wildcatters that could get pricey. unless I could find a lazer for .22 rimfire or something small like that and them make brass, bronze, aluminum, or delrin adapters for each cartridge, that would hold the rimfire lazer.


01-18-2010, 07:35 PM
Mark, had the very same idea myself some time ago but procrastination got the better of me. Glad to see someone took the initiative to actually do it. I've got the same chronograph as you and thought of using a larger hole on the front screen. I've got one of those laser boresighters that inserts into the muzzle of the rifle. Now I've got no excuse to not do it.

01-18-2010, 08:36 PM
I just place a piece of masking tape across the arms, four inches up from the sensor, position the rifle so the scope cross hairs are center on impac point, remove the bolt, look down the bore until and position the chrony so I see the tape.

I guess, if you're not shooting a bolt action, this could be a little difficult though.

Boyd Allen
01-18-2010, 08:48 PM
I pull the bolt, sight the rifle on the middle of the target, (using the scope) and then, standing just in front of the skyscreen nearest the target, lower my eye till I can see light through the barrel. Without moving my eye, I adjust the skyscreens till they are aligned with my line of sight. It helps to have something light colored behind the action. It works pretty well. Obviously, it requires a rest setup that will hold the rifle securely during the process.

El Paso Mark
01-18-2010, 09:11 PM
Paul- Yes, at the range I'll insert it into the bore. I didn't want to set up the rifle to test here at home and possibly freak out the neighbors. They (Osprey) make inserts for the different calibers, so you only have to buy the .223 diode and then whatever caliber insert you need. As I say though, they don't make inserts for the 6mm series, 6.5 mm, or 22 PPC benchrest calibers. I think an old case with the base cut off should work though.

Jerry- I thought I'd need a bigger hole but the laser beam dosen't disperse/enlarge as much as I thought it would. A larger hole, maybe penny sized (?), would be less fussy to align but would still be small enough I think to achieve the desired end.

Ben & Boyd- That's the problem I had, trying to eyeball it down the bore (Bolt action) or over the top or off to the side of the barrel and get it aligned/centered through the "V". I never did get it right (Operator error), and trying to do it by yourself is tough.



Boyd Allen
01-18-2010, 09:20 PM
I am talking about putting your eye in front of the front sky screen, and looking over the screens,(through the Vs), and back down through the barrel, from the muzzle end. If you can see the full circle of light, through the barrel, your eye is where the bullet will be. It's really easy.

ray porter
01-18-2010, 10:17 PM
most any cheap laser pointer will lay in place of the bolt and shine right down the barrel. set the rifle up in the bags and aim at the target then lay the laser in and use your hand to spot the laser between the screens.
on the kind that goes in the muzzle-you dont have to insert anything into your muzzle. they are just the right diameter to fit in inplace of the bolt and shine right down the barrel. if you do insert it in the muzzle DONT FORGET to remove it.

El Paso Mark
01-19-2010, 07:55 AM
I am talking about putting your eye in front of the front sky screen, and looking over the screens,(through the Vs), and back down through the barrel, from the muzzle end. If you can see the full circle of light, through the barrel, your eye is where the bullet will be. It's really easy.

Okay, I understand now. Will give that a try.

Ray- "most any cheap laser pointer will lay in place of the bolt and shine right down the barrel." Now why didn't I think of that :rolleyes: I could have saved a few bucks.

Conditions (Wind) aren't looking good today for testing ammo so will have to put this off 'till the weekend.



01-19-2010, 05:13 PM
I do like Boyd says.... and if I'm having trouble seeing through the bore, like if it's very bright outside and my shooting room is dark and comfy, :D then I'll stick a little bendy borelight into the chamber. I've done as many as three in a row this way and haven't had any problems. I have an acquaintance that always looked back through the SCOPE .... until he scope-aligned an AR-15 and stuck the first shot thru the chrono. Ranged that bad boy end to end.


David S
01-19-2010, 06:08 PM
I also use Boyd's method. Have been for about 15 years since I got my chrono. Must work since I haven't shot the screens yet on my Oehler 35P or the Shooting Chronies I had before that.

01-19-2010, 08:35 PM
I think the precision of it comes down to need.
If your chrono is only needed for ES/SD, then somewhere close works. But if you want actual velocity(as close as you can get) the screens need to be setup with very little tolerance per axis.

~6-7yrs ago I used a cheap plastic muzzle loaded boresighter. I still use one, only better quality.
With gun on target, I put a hand, middle fingers to the optical sensor(Oehler), and adjust the screens for the dot centered in my palm.

But within 6mos of using(the cheap laser), I did the incredibly stupid and 'highly modified' a muzzle by firing with the laser installed..
One of those wind blows over a screen mid group kinda days, that led to worse recovery....

I use 20' screen spacing and there is just no other way I know of to do it as portable -without a laser.
So I picked up another one(nicer) and modified it with a cable attached aluminum chamber plug.
http://img130.imageshack.us/img130/8825/79520128.th.jpg (http://img130.imageshack.us/my.php?image=79520128.jpg)

So I don't do this:
http://img130.imageshack.us/img130/2179/blewit.th.jpg (http://img130.imageshack.us/my.php?image=blewit.jpg)
With this:
http://img130.imageshack.us/img130/8090/blewit2.th.jpg (http://img130.imageshack.us/my.php?image=blewit2.jpg)

This wasn't me by the way.
Be careful