Tac 7/22 TDR (take down rifle)

3/31/09 This section will allow you to follow the progress of this gun from concept through the complete build.

I had this idea while recuperating from a recent surgery. The goal is a small, carbine sized, light weight
action with removable air tubes, adjustable stock, and take down capability so the entire thing can be
stored in a small case. The illustration above was created over a photo of the actual action pieces
below, and is therefore pretty much to scale. The grid is scaled to 1 inch per small box, with the bold lines
every 12 inches.

Let the work begin...

What we have here is basically two complete action prototypes. Both are barreled in .22. The top uses
a Webley barrel, the bottom a BSA barrel. I simply used what I had laying around to start with. The air tubes
use a foot valve to close off the air flow when the tubes are unscrewed from the action. The valve bodies
incorporate a pin valve to open the foot valve when the tubes are then screwed on the action. One of the
actions has a pension for cutting the O-ring on the tube every 4th or 5th time the tube is screwed on, so I
will need to get that figured out. I think a bit more of a chamfer on the throat of the valve body will take care
of that though...

The bottom action, being the more complete, is now functional. I took about 50 shots with it the other
day, and would report the power to be at approximately 18-20 ft/lbs. Still working on parts, I could feel
the striker being dragged along the top of the trigger sear, which made both cocking and shooting
a bit on the rough side. I have since re contoured both the sear, and bottom of the striker, and things
are much smoother. A different valve spring brought the power up significantly, and I think it is close
to the 25-30 ft/lbs I am after. With replaceable air tubes, shot count isn't an issue at this point. The air
tubes measure 12 inches in body length (not including the fill valve and foot valve).

A closer look at the breech area.  The separate loading probe, and cocking knob will allow a pellet to
be chambered without cocking the action. Good for the way I like to hunt. Just barely visible is the little
trigger unit I designed for this action. It is two stage, and completely adjustable. The screw protruding
is actually inserted into the first stage length adjustment hole, and will be replaced with a trigger blade
that will have a through hole to allow access to the adjustment. I just needed something to pull on to set the
trigger weight, and test fire... This fit the bill without having to make the blade yet. I already know that
I will be making new sear arms with a different leading edge shape, to ease cocking effort. I will want
the beginnings of the stock and grip roughed out prior to cutting a trigger blade so that I can taylor
it's placement to my liking rather than try to shape the other parts to fit around the blade. Less work...

The few things I did concentrate on for this build didn't change the way things look, so no new
pictures just yet. I spent some time firing the prototype action. After trying bunches of springs,
I decided on one particular striker spring. I then played with fine tuning the spring spacing and pre load.
I actually spent a good deal of time trying very small changes in this area, and noting the results.
Good thing it's been staying light later into the evenings!

I also redesigned and cut the foot valve assembly for the air tubes. The first ones I made used
a small o-ring to help seal the tubes when they were removed from the action. I found that the
o-ring would occasionally stick to the exit port (maybe once every 20-40 times), and prevent the
action from charging when the tube was screwed on. Normally backing the tube out, and screwing
it back in would solve the problem. Yes, the o-ring sits in a groove, and yes, I tried lubing the ring.
I also tried several different sizes and types of o-rings, with similar results - for those that may be
wondering. The other issue I had with the design was that when the action was charged the valve
stem of the air tube could be heard rattling back and forth if the action was shaken. I didn't think
either of these conditions would win many fans, hence the re-design.The new assembly doesn't use
an o-ring, and utilizes a spring to hold the stem in place when the action is charged.

Last area of attention this week has been the trigger sear.  I re cut several and am waiting
for some new springs to arrive to test them. My main concern in the re-design was the feel
during cocking the action. My original design on the sear left a slight hiccup in the stroke just as the sear
was about to engage the striker. I've cut a couple of different leading edges on the sear to test.
The goal is to smooth it out...

It is one thing to pick a gun up, and go out and shoot it. It is a whole nother ball game to
not only be able to decide what every aspect of that gun is, but then try to figure out exactly how
to go about making it work the way I want it too. Good thing I am stubborn!

4/4/09 - A bit of frustration has crept it's way into this build. When I originally cut the trigger
units for these actions, I did so without a striker spring, nor any trigger component springs
in the action. The pieces all look like they should work together, and they do... At least on the
one action I have functional. After assembling the first action, I have a fair number of springs
to choose from for the striker, and a fair number of springs for a trigger unit. But, after putting
this one together and testing, it became clear right away that I was going to need a stiffer
trigger spring. I scoured my shop, and found one that works perfectly. Only problem is that it
came from an aftermarket carb jet kit for a Kehin FCR carb off my motorcycle. And ... I only have one.
The feel is good, the release is clean, and the weight is adjustable down to a decently light feel.
I really like it!

I ordered a bunch of springs that I thought would be close to what I needed, but none of them
worked. I found a few more to try that should be here early next week, and jeez are they
expensive - just to try. If they don't work it may lead me to designing and cutting a different
trigger unit for these actions. While unable to go to sleep last night thinking about this problem
I drew up a new design. It will change the lever configuration and leverage ratios. But,
will also relocate the trigger blades placement below the action. Something I am hoping
to avoid.  I'm not an engineer, mathematician, or technical wizard with a wealth of experience
under my belt. Most of what I do is trial and error, with the emphasis on the error part...
I get that if I keep at it, a year from now I will know a great deal more than I do right now,
but, this learning procedure can be a pain while in the midst of it!

I was able to get a few more parts started for the rest of the build, such as the parts
for the main beam of the rear stock assembly, and the shell for the silencer unit. The
problem with the trigger unit tempered my enthusiasm though...

On the bright side, the one action I do have shooting is working pretty well. I probably have
a couple of hundred shots through it already. Loading a pellet is smooth. I do like the
trigger feel on this one. While I don't really have a grip to hold onto as of yet, just pointing the
action seems to place the pellet in a predictable location down range. I've been using a set
screw in the top of the breech to align the barrel end with, while giving me a rough aim on target.
The discharge sound seems consistent. While not being an accurate measure of performance,
it does give me hope that I am at least in the ballpark.

4/8/09 - Several samples of small springs showed up yesterday. I took a few minutes during
the day to at least try installing them into the trigger units to test, and found a few combos that
seem to work.  New trigger sears are in order though... There was still a decent hiccup in the cocking
stroke as the sears clear a lip in the striker.

Early this morning I cut a couple of new sear arms to test, altering the shape of the leading edge.
I had basically convinced myself that these trigger units are not going to work, and that I am going to
have to return to the drawing board to solve the problems I am experiencing with them. That is
until I installed a new sear arm. I stumbled upon pay dirt. The cocking stroke is now nice and smooth.
Sear engagement is nice and positive, and the trigger can be adjusted down to a light, crisp release.

So, at least now I have a trigger group to work with. There are however a few other things that I have
been struggling with that keep this build on the frustrating side. I am still trying several different
alternatives for the foot valve assembly, and have thus far met with some pretty disappointing
failures. I am going to ponder this problem for a while before attempting another alternative.
This means that for the time being, I am going to build up one of the actions with an air tube that
won't be removable. I'll come back to this problem at another time... and concentrate on the rest
of the gun for now.

In order to pull off the complete build as I originally planed will require the design and execution
of many pieces I have yet to design. To do the furniture, I will be making mock ups, and creating
molds to cast synthetic grip and fore arm components, along with a cheek piece. I also want to
make the action removable from the stock, much the way a shotgun fore arm is removable.
Push button, and click type arrangement, so that take down will indeed make for some small
components.

I am not real sure I have the patience to wait till I have the time to figure out, and build all
this stuff to start shooting the gun, so I for sure will build up one of the prototypes in a simplified
manner so that at least I have something to continue shot testing with... I will probably come up with some
sort of a stock to drop the action in, so that it will be a complete, usable alternative to what I originally
envisioned in the illustration at the top of this page.

I completed the majority of the machine work for the removable but stocks for the two prototype
actions. Length of pull is adjustable by pressing the brass button and sliding in or out. Adjustments
are in .375" increments from about 12.5 - 15.5"  - roughly. I haven't really measured yet... I will be
designing and making a new pad assembly. I used one of my standard set ups to get the ball
rolling. I want to make something a bit more tactical in appearance, with some more angular
contours. I will need to make a new mold for the pad, so look for that in the near future.
I also want to make the "wiper" at the front of the outer tube from a hard durometer rubber.
This will help to keep any wiggle in the assembly down to a minimum, while also preventing
scuffing of the final finish along the adjustment area. A mold will be made for the "wiper" as well...

4/21/09 - I had the opportunity the last couple of evenings to start roughing out the stock pieces.

At least now the gun is starting to look more like the original concept illustrated at the top. Those that
are good at looking at things the way they will be when finished, will be able to see just how close it is
to the original idea I had. The stock pieces are made out of walnut scraps salvaged off the shop floor
that had accumulated over the winter. Once I am satisfied with the the shape, fit, and detail involved
in the pieces, I will need to make molds out of them for producing synthetic parts using a two part
urethane resin. The parts will be coated with a textured finish prior to the mold making process,
which will impart a good textured finish on the cast pieces. The ridges will also be added to the
fore arm piece prior to texturizing and making the mold. The easiest way to do it is by simply
gluing strips of cardboard to the wood with crazy glue, and because is looks like hell, I will wait
till I am closer to the mold making point to do so...

Other tid bits still being worked on and tested are trigger sears. I have been tempted a couple
of times to scrap this trigger unit, and design something new. Every time I get close to that point
I try a different sear angle, or shape, or length, etc... which breaths new life into the unit.  Note: I am
still using the screw sticking down as a trigger blade...

To understand why I contemplate changing the trigger unit,
you need to understand how picky I am about triggers. Everything I have tried so far has worked.
Some have been quite decent, but I feel it can still be better. I am so far satisfied with the unit
I now have working in this prototype.

I am also working on a few pieces that will make the action
itself easily removable from the stock with the press or pull of a spring loaded lever, and latch system.
I currently have the pieces mounted on the other action. When I have them all figured out
and working properly I'll get a set cut and fitted to the stock, and this prototype.

I've been plinking a bit with this action with just a red dot sight mounted on the scope rail,
and will say that I am so far pleased with the way the gun loads, cocks, and shoots. Overall
length, with the length of pull set at 14.5 inches, is 31 inches from the curve of the pad
to the tip of the muzzle.

4/23/09 I did a bit more work on the furniture parts...

Making molds is difficult. Everything will show up in a mold. A hair, sanding marks, even finger prints
 will easily be captured in the resins used to create a mold. So, goes without saying that there will
need to be plenty of work done to the various parts prior to the mold making process. There can be
no sign or trace of grain left on the wood, or it will appear in the final cast pieces. I'll get back to that
at a later time, as my goal now is to just get the gun shoot able/usable. Which it basically is now.

I took approximately 150 shots today with the 4X12 scope mounted in the picture. I started with
a 4X scope, but it was difficult to see where the pellets where hitting at 50 plus yards, after doing
a 30 yard zero, so I switched out to the 4X12. Accuracy at 30 yards seems to be what I expected out
of the BSA barrel with no surprise POI drama to contend with. I was easily getting somewhere
around 20 - 24 shots off a 2700 psi fill, no problem. More testing will be done as things come together
more. For the most part, I think the performance is right where I expected everything to be.

I tried a different breech seal method on this action, with no seal on the pellet probe itself.
I also wanted to keep the seal easy to replace in the event of failure. I am for sure getting a little
blow by out of the arrangement, so will need to redesign that set up. Worst case I will simply
add a seal to the probe, and go for a traditional set up there.

Last thing I will look at in the next few days is the trigger, again. I have just the slightest
hiccup in the first stage travel to address. Second stage seems to be pretty good, and let off is
real close to what I am looking for. The hiccup could just be some dirt or debris in the assembly.
There's plenty of dust and grit on the work bench, and I am constantly having to clean the
actions out... Now that the weather is coming around I can get the shop door opened up
and get a good spring cleaning done...

Prior to making molds for all the pieces I will need to produce any more of this action
I am going to dress one of my prototypes in a charcoal laminate stock with ebony accents.
The action will be finished off gloss black with polished aluminum bits for accents. The other
action will go into either a walnut one piece, or perhaps a two tone walnut finished unit, the
action black and gold as in the original illustration.

4/24/09 - I think this pict kind of says everything that needs saying...

 I spent 20 - 30 minutes walking around on the hill out behind the house, and this was the result
of the shot testing I did up there. I would have to conclude that it works pretty good. I will need to
get a real trigger blade cut and mounted before I go again. That screw hanging down works, but
leaves plenty to be desired! Also, the shroud work comes next, as this little sucker is loud.

4/29/09 - Enough beating a dead horse... I recut trigger units for the prototypes.

The one on the bottom was the original. So of course the one on the action, as well as the unit
just below it are the newer ones. While the original unit worked, it was finicky, and somewhat
inconsistent. One day it worked great, the next it hiccuped. One day it would handle bumping
(actually smacking) the action, the next day no matter how firm I made the adjustment, it would
misfire when bumped... So, a new grouping now rides the bottom of the action. I am much
happier with this unit. One additional lever, as well as longer length with more leverage and
adjustment range makes for a nice trigger feel. Glad I finally decided to do it!

I also reworked the furniture... Which is still raw and unfinished in the pict below.

I did dye the main beam of the stock with a transparent ebony dye, which allows the grain
to still show through, but adds a color difference between it and the other pieces. With a black
action sitting in it, I think it's gonna look pretty cool. The cheek piece was reshaped as compared to
the first one I did. This allowed me to switch from high mounts, to low mounts for the scope. I
also reworked the breech/probe seal arrangement, which eliminated any blow by.

With the changes to the wood, and the new trigger group, the gun is shooting quite well now.
Next will be the shroud work, a dust cap for the fill nipple and a trigger guard. This will pretty much
wrap up all the major design and development work involved with this project.
With some additional testing I would expect to start building more of these and the
Bullhead LRP pretty soon.

If you've made it this far down the page, you must still be interested. Pricing isn't firm yet, and will depend
on several options, including caliber, stock material and degree of take down options, as well as type of finish.
I will be making some of these with non removable air tubes (somewhere between 14 -16"),
some with removable air tubes (12"), and some with quick detachable stocks.

I am not taking orders for these, just trying to judge interest, and get an idea of what to build.
If you think  you may be interested in purchasing one of these custom pieces, give us a call and we can
talk about it a bit 304-273-0937, after 6pm est.

5/1/09  New trigger = Gooooood! I like it.

This little fellow made the mistake of making himself visible about 37 yards outside of the
shop door, while I was working on a trigger guard for the action.

Shot was taken off hand. This little action has turned out to be 35.5" of absolute joy to shoot.
At 48 yards with the gun rested on a jug sitting on the table of my band saw, the gun is
producing tight little clover leaf groups, with hardly a "pu-phoooot" type sound. The pellet
strike is noticeably louder than the discharge sound, at this point.

I carefully stoned and polished, as well as lubricated all the trigger components, as up to
this time I have been using the action with pieces fresh from machining. Cleaning and dressing
everything has made an awesome difference in the feel, and it is just what I was looking for.

I got an itch, and have decided to make one of these actions in 9 mm, just for kicks.
The air tube will not be removable, and the overall length of the tube will be about 2.5 inches longer
than what I have now.  Stay tuned....

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