July 24/05 Last Revised 1/17/2006
Accurizing the Handi Rifle
Accurizing the Handi Rifle
To eliminate barrel, action or any other vibration is not possible, we can only reduce or minimize the amplitude and try to make the vibrations as uniform as possible. With the barrel separated from the action and a marginal lockup as in a Handi rifle the task is not easy.? Besides we have a loose hinge and a loose forearm or rather a disconnected forearm.? There are six separate areas that I can identify that need to be addressed to create a more connected unit. There are many more vibrations but most of them are benign or rather inconsequential to the accuracy of a Handi rifle.
These are 1. The barrel face and standing breech, 2 The Underlug,? 3. The barrel section behind the hinge pin,? 4. The hinge piece on the forearm,? 5. The barrel lug and screw holding the forearm.? 6 The forearm tip.
We are dealing with three separate vibrations producing items, first the longitudinal vibration from end to end and its amplitude. Next are radial vibrations or torque caused by the bullet forced to rotate by the barrel twist. Third is the time the bullet is in the barrel. The last one is easy to address by load development and accuracy hand loading.
Starting with item 1. The barrel face and standing breech
It is of utmost importance that the barrel and the standing breech fit tight together when the action is fully closed. Absolutely no gap is what we are looking for. If there is a gap you need to shim the hinge pin seat, or build up the seat with weld and refit. Shimming with steel shims is easy to do. It is expected that the barrel latch make
?full and solid contact with the latch seat.
Item, 2 The Underlug side Shims,
When the standing breech has full contact with the chamber end of the barrel, it is assumed that the hinge pin seat is aligned with the breech. Since the underlug has no contact with the action well, the torque of the bullet will rotate the whole barrel as far as the hinge pin will allow, causing excessive radial vibrations.
There are four raised portions in the action well casting that supposed to provide contact with the under lug.? Clearance in these four aries is too large to provide a rotational stop or restrainment for the underlug.
Remedy is to fit four shims two in front and two in the back by either soldering or glue them in place with J-B Weld. Do the rear ones first fit one side and then the other. You get the thickness size of shim by taking measurement between the raised lumps in the action and the under lug divide the difference by two.? Fitting is slow and care must be taken not to force the barrel to one side. Lipstick works well to see where you need to hone the shim.
Item 3. The barrel section bedding behind the hinge pin,
Together with the under-lug shims bedding this barrel section in the action aria will provide a connected unit and enhance the rigidity of the lock up
The material I used is called Devcon Steel Putty it is a very stiff mix and does not flow. It has poor adhesion on smooth steel.
The mix is 1:2.5 Resin hardeners/steel putty. This mix is nonshrink and can be machined.
To get good adhesion the inside of the receiver has to be sanded and all bluing removed where the bedding goes only the upper radius part is bedded. Best adhesion is achieved with an epoxy primer coat, which is applied to the steel with a q-tip. The primer is made from 51Cure industrial epoxy mixed at a ratio 1:5 hardeners to resin.
I use STP as a release agent on the barrel, barrel face and standing breech for this type of application. The STP is applied as thin as you can with a q-tip.
The mixed steel putty is rolled out to a 1/4" roll or so to fit between the hinge pin and the standing breech face, but a 1/4" away from the face so no putty gets between the barrel and the face
To get the right amount of steel putty and exactly where to put it I used a roll of modeling clay and squeezed it in like I would the steel putty.
It is vital and important that no epoxy putty gets down in between the underlug, or the barrel and action may get stuck together.? Bad news!
Needless to say all surfaces to receive the bedding are cleaned and washed with acetone. Be careful not to get any STP on you hands and the steel bedding area.
Hold the action in a vise so you have both hands to hook in the barrel without touching the putty, and then ease down the barrel into battery by tapping and pushing very slowly, no retraction is allowed. . The barrel is the tapped down with a wood block until the latch fully engages.
Remove excess putty on top with sharpened piece of wood. Clean the wood and dip in water and trowel?? for a nice smooth finish on the exposed putty.
51CURE will harden in 12 hours the putty takes a bit longer depending on room temperature. Keep a test sample with the action to monitor the setting of the putty.
When the putty is hard but not fully cured, put the action into a vise wrap the barrel with a rag. Tape down the barrel latch lever and give the barrel a couple of good whacks with a piece of 2x4 or a rubber hammer to brake the bond. Remove the barrel and clean up inside the action apply some oil to the barrel and put the barrel back together. Tap down the top again making sure the action is fully closed and let the putty cure for a week.
Item 4 and 5. The hinge piece on the forearm,
Remove the two wood screws from the hinge piece and fit it perfectly to the action using lipstick and scrape away any high spots. Once you have perfect fit glue in the screw holes with two small dowels and cut them flush. Remove a little wood with a round file on the rearward side of the forearm stud hole.? Hold the hinge piece in place and snug on the forearm with the o-ring in place. Make four thin wedges and tap them in between the wood and hinge piece with glue on the wood side only and line thing up all around and wedge the hinge piece tight against the receiver.
With the glue solid on the small wedges, remove the forearm and the hinge piece. Rough up the back of the hinge piece and mix up some Brownell steel bed and fill in between the hinge piece and the forearm without disturbing the wedges. Reinstall the forearm, line up the hinge piece and tighten the barrel lug screw on the forearm. The bevel on the screw will shove the forearm back for a good compression fit against the receiver since we relieved the screw hole a bit. After the steel bed set you reinstall the two wood screws in the hinge piece.
Next we bed the barrel solid into the hinge piece and a 1/2" of the wood with steel bed and the o-ring compressed tight.
The wedges will push the hinge piece
against the receiver and the stud bolt and is allowed to set up
in this position.
The stud bolt is tight against the rearward edge at this point and counter sunk bevel is above the screw seat and off toward the hinge. When later the bolt is tightened the bevel of the bolt will force the forearm against the hinge radius when fully seated in the beveled countersink. ?Hence a very tight connection the rifle will not fall open. A tab of Molyslide will lube the hinge action.
The treatment of the hinge piece and the
bedding of the barrel at the hinge piece weren't meant to resist
rotational forces or torque. But act as a cantilever support when
you put 15lbs of pressure against the barrel at the forearm tip.
Since the bolt is near the center of the forearm the forward
pressure is transferred to the hinge piece, which in turn will
create uplift on the hinge pin.
All this unifies the system and dampens vibrations. Since I don't have any vibration measuring equipment I can only judge by performance in use. The system as described has been very positive in responding to say the least.
At a later date I will add a 1/2" threaded brass insert for the forearm screw with a recess for the o-ring. The insert will set in steel bed. This will further unify the setup. LM. McPherson describes it in his book, only he uses Steel Bed to make the pillar.
Added 1/17/2006 The latest I have done is
open the stud hole in the forearm with a ? N course tap and
made a pillar from
Item 6. The forearm tip.
We have three options. To leave as is free floated.? Glue in a wood wedge and apply 10-15 lbs uplift (my preference) and fill the void with Dow Foam, or install an adjustable barrel tuner with a nylon plunger in the tip, with which you can vary the uplift pressure from 0 to whatever. Next winter I make a couple of them. Added 1/17/2006. You can solid bed the tip ? and tighten the forearm screw to put uplift on both the hinge and the tip. This works really well when the free floated part is filled with silicone caulking .
Handi ejector tuning.
Remove the ejector from the breech. Leave the ejector spring stop-pin in place. When taking out the two other pins put the barrel end in a plastic bag so you don't have stuff taking off into orbit and never to be found again. Watch out for that little plunger spring and the wee plunger.
Once the springs are out check the seat to make sure the ejector is not sticking out past the barrel face,
Take a stone and break all the edges. Place a piece of fine 800grit wet and dry paper on a flat steel plate or a thick piece of glass and rub all three sides and the up stand face that fits against the standing breech nice and smooth.
Now you need a high speed buffer and polish all the flats to a mirror finish. I use a buffing wheel on my bench grinder coated with Alo Sheen an Aluminum oxide buffing compound.
Get two flat wood tongue depressors or the wood ice cream sticks and cut them 0.300 wide. Glue a strip 800-grit paper on one side and a 1200 grit paper on the other side. And polish the inside of the ejector race way top and bottom, not much is needed.
The main spring can be beefed up by placing a smaller spring inside the big one if you can find one. Or you can reduce the compression space of 0.828" at ejection. The compressed spring can't exceed 0.633".
A small piece of wood or a steel pellet can be used to give the spring some more compression. Check to make sure the ejector goes in flush with the spring in place. Do that before you put the pins back in.
Hand Loading for the Handi Rifle
Especially for the high-pressure cartridges it is advised to full-length size with the dies set to produce 2-3 thou headspace.
Handi's have springy action and if the shoulder is not set back each time the action will not fully close. Setting the shoulders back each time you reload, case life is reduced. So watch for case-head separations after 8-9 reloads.
Uniformity and concentricity in hand loading is the name of the game, you can never have too much of it.
I do the following with all my brass. Trim cases to the same length each time you reload them. Uniform the primer pocket depth. Re-drill all the flash holes to the largest hole size about 0.081". Outside neck ream 75% of the case necks perimeter.
Remove the burrs on the inside of the flash hole, which are inside the case. Clean cases and the insides of the neck.? Produce loads that have the least velocity variation.
PS. Handi's are not overly friendly to maximum reloads. Further tweaking instructions can be found on another one of my other web pages. Some detailed pictures can be found on these pages. At present I don't have a camera to take real small detailed close range pictures. I am working on another Handi Conversion a 6x47 (6mmx222Rem Mag.) the details will be available on a new page. This is a very mild short range varmint cartridge.
The hammer spring is not up to the task of firing the CCI small match and magnum primers. I hope a new hammer spring will cure it. These primers also gave trouble in the Viper BR action.
Note: Jan19/06. I have installed a new hammer spring and solved the problem of the non fire CCI small match primers. They fire well now. Hammer springs don't seam to last very long? The two Handi's have now new hammer springs. Keep spare ones handy.Good ignition is very important for consistant accuracy.
Fred The Reloader and Wildcatter