How would you do this?

[AccelR8]

I have to install a front sight ramp on a barrel that already has a rear sight mounted. The ramp is attached with a single screw. I need to get the front ramp aligned with the rear sight so that it doesn't use up a lot of the rear sight's windage adjustment.

My plan is to center the rear sight for windage adjustment, put the barrel between centers in the lathe, put a scribe in the QCTP and adjust it's height so the point of the scribe is in the notch. Then move the carriage down to the muzzle end and use the scribe in the QCTP to mark a line to locate the hole for the front sight ramp. Next, move the barrel to either the mill or the drill press with an X-Y vice and using an edge finder position the center or the barrel precisely under the quill. Then using eyeballs and strong magnification, rotate the barrel so that the scribed line is right where a small center drill in the chuck will contact the barrel...does my explanation make sense?

The other possibility is to use a level on the top of the rear leaf and edge finder-and center the muzzle end under the quill. Not sure which method would be better.

Advice?

 

[shortgrass]

I would use my Forester site mounting jig with the (front site barrel) extension. OK, you don't have one. What receiver is this barrel mounted on? Sounds like you're making an easy job hard....

 

[AccelR8]

I would use my Forester site mounting jig with the (front site barrel) extension. OK, you don't have one. What receiver is this barrel mounted on? Sounds like you're making an easy job hard....

CZ455 22LR so two screws and the barre pulls out of the receiver.

 

[shortgrass]

Leave the barrel in the receiver, don't remove it. On the bottom of the receiver there will be some place to use as your reference. A flat, the edges across the loading port, some straight line that is 90 deg to the sites. If I did not have site mounting jigs, I'd use a ground tool bit to locate from there on the mill table. After you get there, shim the action so its level (as close as possible), and fasten it down (your choice how). Support under the area where you want to drill so it doesn't spring away. Use an edge finder to find center and drill the hole. For ease, I locate the receiver straight using a table slot before I fastened the barreled action to the table. I'd try to start the tap from the drill chuck by hand so it was straight to the hole. It's a straight forward machine set-up 101.

 

[Dusty Stevens]

Id definitely sweep in your mill- every part of it then check whatever devices youll be holding your work with. You cant get too precise with something 15”+ away from your reference point

 

[kendog]

Set it to mechanical wind zero of the existing rear sight with a GOOD collimator. Clamp it or set it using a little bit of crazy glue and locate your hole(s). I use a Sweany Sight-A-Line with a bullseye feature rather than the more common grid. The rings subtend to 4 MOA and it is very easy to locate a sight where I want it. It has never let me down. Can get to well within 1 MOA of Mech zero with it. I have a Forster jig and a 9 X 42 mill, but this method gives better results.

 

[buckhunter62]

Set it to mechanical wind zero of the existing rear sight with a GOOD collimator. Clamp it or set it using a little bit of crazy glue and locate your hole(s). I use a Sweany Sight-A-Line with a bullseye feature rather than the more common grid. The rings subtend to 4 MOA and it is very easy to locate a sight where I want it. It has never let me down. Can get to well within 1 MOA of Mech zero with it. I have a Forster jig and a 9 X 42 mill, but this method gives better results.

Your method of lining it up on the lathe sounds good to me. Cheap & easy way of doing it. You won't need any special tooling.

 

[AccelR8]

Thanks for the replies. You know, many times over the years I have considered buying a collimator but always concluded that for me it wouldn't be worth it. Then, I wind up mounting scopes at least several times a year, bore sighting by eye and then zeroing at the range. Had I bought a collimator years ago it no doubt would have paid for itself in ammo savings.

I actually have a question about collimator usage; something I do not understand but I don;t want to go off on that tangent now.

Years ago I did buy a well known brand of laser bore sighter set at a local retailer. I used it one time and the next time I tried to use it it quit in the middle of the job. The short story is, the retailer and the “manufacturer” both told me, though luck warranty period as expired. I won't be buying another.

This particular job is a new challenge for me as I've not done it before and wanted to seek advice before jumping in.