Tuesday, May 28, 2013

Anschutz Front Sight Adapter for the Tech Force TF79 / AR2078A

Took a couple weeks off airgun posting due to increased workload at the shop.  It's a seasonal business and we're in full season.  I have been making things--but mostly machine tooling related items.  I managed to eek out a project yesterday for my TF79 target rifle.  I had already upgraded the rear target sight with a Baikal diopter, and recently found a spare Anschutz front sight in one of my parts bins.  Aside from the higher overall quality of the Anschutz unit compared to the TF sight, I've got a lot of inserts for the Anschutz, so it makes sense to get it onto the rifle.

A piece of 1" round aluminum predrilled with a 0.500" though hole will make for a good start.

The barrel OD on the Tech Force is 15mm--I don't have a 15mm bit and sorely need to buy one.  So, guess I'm doing it the hard way.

Through drilled with a 9/16" bit to provide clearance for a boring bar.

The boring bar barely fit, but that's enough.  Bored out the hole to just over 15mm.

Faced the end.

Used the compound to cut a taper.  Just eyeballed it, as there was no need for a specific angle.

With the taper done,  the piece was moved to the mill.  The card stock should help prevent marring the sides of the work from the vise jaws.  Just going to do something simple.  Again, no real measurements.  Only noted how deep the cut was.

Cut a flat.

Flipped the piece and cut a flat 180 degrees from the first.  Matched the depth of the first cut so they were equal.

A high speed pass on each side left a nice finish.

Sanded the piece to 500 grit with an oil soaked piece of emery cloth. 

The Anschutz sight still patiently waits.

Needs dovetails as well as some set screw holes for mounting to the barrel.

The Tech Force barrel had a milled flat for a set screw exactly 120mm from the muzzle.  Lacking a proper height gage, (Yes, I'm a bit under-tooled) I adjusted a surface gage to the correct height and scribed the mark.

Did some rough layout for the dovetails.  The Anschutz sight looks like it requires 60 degree angles.

This was alarmingly uneventful.

Located the hole position for the first set screw.

It was spotted and drilled.

Then tapped M5 x 0.8mm--the largest size screw that would fit in the milled pocket on the TF barrel.

Decided to add two more set screws to the adapter.  

Just needs some clean up.

Sight screwed in place.


I took some time to get the new front sight in a similar location height-wise from the bore compared to the old.  Had to do minimal rear sight adjustment to get on target.

Check back soon.