[cajungeo]

I made this adjustable tuner for my Fajun Silhouette Stock and fluted A&B barrel. I also made another for my Fajun Sporter Stock and GM barrel. Your stock thickness/screw length may vary!

Tun1 shows parts used. #8-32x3/4" Stainless Allen head screw, #8 Stainless locking nut, and a spent 22 LR case. Total cost was 65 cents!

Tun2 shows tools used: Drill motor, Allen wrench, drill bits: (1/8", 13/64", 5/16" dagger, 7/16" dagger), Acraglas or 5 min epoxy, acid brush, straightened paper clip, masking tape, alum duct tape, Tru-oil (for stock touch up).

Marked the place to drill on the outside of stock 1 1/4" from end of stock, centered (this is where my sweet spot was located). Pressed down a strip of alum. ducting tape on inside of stock to keep it from splintering. Drilled 1/8" pilot hole thru stock. (Caution twist drills can pull you in deep quick, use light pressure!). Used 5/16" dagger drill to counterbore outside hole to a depth of .375" (ref tun3). Used 7/16" dagger to counterbore inside hole to a depth of .420" (ref. tun4). Open pilot hole up with the 13/64" drill.

Tip: Use masking tape as a drill stop by wrapping drill bit where you want to stop, so you won't go too deep. 6 wraps should do it.

 

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Assemble screw, and lock nut in stock. Tighten; wedge a small knife blade to hold nut. Check thread protrusion, and make necessary tweeks (ref. pic tun5) . If it looks good, disassemble. Clean dust from hole, re-tape, apply release agent to screw, and 22 case, let dry. Use alcohol to degrease nut. Reassemble with 22 case over screw threads. (ref pic tun6) .

Pot with acraglas or 5 min epoxy. Force out all air from around nut with straightened paper clip. Let cure over night.

Remove screw, 22 case, and clean flush to stock! Use dial calipers butt end as a depth gauge, and measure nut hole depth to top of nut, with caliper butt parallel to bore channel. Now measure, and cut the 22 case so to nest just below surface. Radius the potting so the 22 rim will seat below surface. In case you haven't figured it out yet I used the 22 case as a pressure pad so the softer brass will not scratch the barrel. (If you aren't as picky, at least smooth the screw end with 320-sand paper). (ref pic tun7) .

Use Tru-oil with a little mineral sprits to thin a bit, touch up any exposed wood to seal. Also use a Q-tip to seal screw hole against moisture. Let dry over night.

 

[cajungeo]

Finished product, at net adjustment is flush on both sides.

 

[cajungeo]

To adjust: turn adjustment screw until it just touches barrel. Put Allen wrench at a parallel or perpendicular position. Remember location or better yet a spot of paint on one side of the adjust screw head to use as an index point. Shoot 5 shot groups/turn screw 90 degrees till group improves, note on a logbook beginning of sweet spot. Repeat till groups start to open up, note index position in logbook. Set adjust screw in the middle of the sweet spot so weather changes will have a minimal effect.

With this adjustable tuner, I can tune to match different ammo. By using a logbook I can note how many turns, or fraction of turns to quickly tune for any ammo I use.

The only down side is when disassembling, don't loose the little 22 case cap!

I had fun coming up with this little project, now I will build another for my target 10/22. It sure looks better than the cardboard I had before.

 

[cajungeo]

Ok this is a Quick & Dirty Tuner, (pressure pad) for those who like things simple.

(1) Go to the range with your 10/22, favorite ammo, and a few strips of thin cardboard, such as an ammo box. By experimenting with layers of card stock placed under the barrel and forestock tip until best group is obtained.
(2) Take this home, and measure thickness of cardboard build-up with your calipers. Now all you need is an empty bleach bottle, cut out strips of this flexible plastic to build-up to match cardboard thickness.
(3) Trim strips so it is not seen with barrel in place.
(4) Use contact cement, Fast Tack or other adhesive to attach build-up to your stock. Clean up access. Reassemble Rifle. This will keep stack-up in place till it cures. By using the contact type adhesive you can easily remove it later.
(5) Let cure. You’re done. Good shooting.