Derrick Works his Magic on a Crosman 38T, Part 6

Derrick finishes up the grips.

Spotting the holes for the palm shelf with a transfer punch.
I broke down and used a walnut colored Danish oil on the entire grip. There was some hairline checking (cracking) in the wood that I didn't notice before. By the way, the wood was air-dried as opposed to kiln-dried for anyone who takes note of such things. There's now about 6 coats of oil on the grips. I did not coat the stippled areas. Although they do pick some up around the edges as well as oil from hands. I didn't set out to artificially age the grips, but they do look more appropriate on a 38T if they appear to be 25 years old. The wood color is very reminiscent of the wood Walther used on their match guns from the late 70's and early 80's.


Drilled two holes and turned them into an oval slot. Since the grip was made for my hand it needs minimal adjustment range. If this was a production grip, the slot would have to be three times as long.


I countersunk the slot on the inside of the grip for a nut with a forestner bit. Now, I just need to attach the grips to the gun and I'm ready to shoot.

Perhaps the world's only .20 caliber match gripped Crosman 38T.








Not bad for winging it. At least now, I know which parts of the grip design need to be planned in advance. Notes to self: For the future, the palm shelf attachment to the grip should be considered FIRST. Also, consider how to lock the grips together earlier, making that connection as soon as possible to work the grips essentially as a single piece.

Derrick Works his Magic on a Crosman 38T, Part 5

Now Derrick Starts on the palm shelf.

I still need to make the palm shelf for the match grip. A contour gauge will help fit the shelf to the right side.

It's just pressed against the grip and the grip's profile can be transferred.

The line transferred.

Back to the scroll saw.

Here's another piece for the scrap bin. I hated the look and found that the thickness was too difficult to fit to the grip. Nick would call this a prototype. I made several prototypes like this. None of them suited the grip in fit and aesthetics. I took the next few days off and got away from the project.

I tried a much thinner piece of walnut for the shelf this time. I'd started at 1/2" and was now using 1/4".

Cut out.

Went to a sanding drum chucked in the drill press. Just did some quick edge clean up.

You can just see some of the failed pieces on the work bench.

The 1/4" thick palm shelf will be too thin to attach directly to the right grip. I found a use for a piece of "prototype". Just a couple quick cuts to get it mostly rectangular. Not worth it (or safe) to use a power saw on a piece of wood this small.

I'll spare you the drum sanding pics. The block is flat on one side to attach to the bottom of the shelf. And flat at 90 degrees to attach to the gun. I'm not comfortable screwing pieces this thin together. Have you tried this Gorilla Glue stuff? It's stronger than the wood.

Quick eyeball test fit. You still think maybe I have a plan? Seriously, you must be new here.

Glue me baby

I still don't have a plan. Maybe tomorrow.

In a moment of profound forgetfulness of the recent past, some idiot decided that the shelf should be stippled to better match the grips.

I played with the contrast and light to give you a pic of how sharp the stippling texture really is.

I really liked the wax finish, but decided I'd better add a walnut Danish oil to the wood for better protection. This is only one (still wet) coat.

Derrick Works his Magic on a Crosman 38T, Part 4

Derrick is still coming to grips with the project...

Test fitting the two halves together.

I skipped over showing the sanding steps. Too boring. Tips: "garnet" type sandpaper is substantially better than aluminum oxide papers for wood sanding. The areas to be stippled do not need to be glass smooth. About 100 or 120 grip on those areas will be more than adequate. The non-stippled areas should be taken to about 220 grit. I don't see any real improvement going smoother.
The finish you see half-applied above is just wax from a tack cloth. I like it so much on this piece of wood, I think it's the only finish I may apply this time. I'll burnish the wax into the wood with a silicone cloth to remove the stickiness of the wax..

Stippling time. I use a Dasco Pro 7" scratch awl. Dasco model #431-0. It's heavy enough to punch the wood smartly and leave a clean impression. I've seen people use a nail and a light hammer. Too hard to juggle the grip (or stock) a nail and a hammer. A while back I also purchased a set of stippling tools that looked like a punch set with diamond-shaped serrations on the faces. All they did was smash the wood. Good stippling has a somewhat sharp texture to it. The scratch awl does needs to be re-pointed occasionally to keep it sharp.

Here goes nothing. Great care needs to be taken when working near edges as you do not want to punch through the side and have a tear out. You also don't want to punch through yourself. As I can unfortunately attest!

When working up to areas without stippling, it can be helpful to simply push the awl into the wood to create the holes and form the border.

Many, many holes make up the texture. That wax finish looks pretty good.

While I was stippling, a friend timed me at approximately four hits per second with the scratch awl. We decided that I had between 48,000 and 50,000+ punches into the wood. OCD. Carpal tunnel. Insanity. Here I come.

The right-side grip bolts to the 38T's frame. The left is attached via a metal clip to the CO2 cartridge. I'm going to lock the grips together magnetically.

test fitting

50,000 stipples......

No pics of the work. I simply spotted holes for the neodymium magnets and glued them in place. The magnets are insanely strong for their size. Now I need to remove any play in the grip halves. A couple pins should work.

Used the lathe to face off some 3/16" diameter steel rod. You can put a very square face on the rod in a single pass.

Here's the 3/16" piece that I'll make the pins from.

This looks like a good spot for a pin.

Here's another spot for a pin. Two will do it. Dilemma: How to transfer the pin holes from the right grip to the left accurately? I used a small piece of the 3/16 rod and turned a point and radius to act as a transfer punch. I lined up the left grip, pressed the grips together and the tool left a clear mark to center the pin holes.

Here's a close up of that locator. Just a simple transfer punch really.

Pins are glued into one side of the grips. They mate into the other side and have no slop in the connection. The rare earth magnets are almost too powerful. The grips don't want to come apart once attached.

I had drilled much earlier for the CO2 piercing screw hole. Extreme relief when I saw how well it lined up.

Almost home now. Just the palm shelf remains. This is clearly not a look one associates with a revolver. The ultra high-end Korth revolver served as the initial inspiration for this grip project.

I see a few spots from these pictures where I can tighten up the fit between the grip halves. Now that the pins and magnets are in place, the grip even becomes an "assembly" when it's not installed on the 38T's frame. I'll run the "assembly" across some sandpaper and close the dimensional gaps on the tops and bottoms.



More to come...

Derrick Works his Magic on a Crosman 38T, Part 3

Derrick's chronicle continues...
So my lack of a plan almost caught up with me. I "conveniently" forgot that the frame of the 38T is 3/4" thick. There would be no way to just set a pair of "match" grips onto that thick of a frame. What was I thinking? Well, I was probably thinking that when I first saw the 38T I thought how nice and easy it would be to make some exact replacement grips. Which is true. This gun would be an excellent candidate for a nice pair of custom grips with minimal inletting--Unless you decide to make target grips--Then you have to make the frame fit INTO the grips. I think I've still got enough wood here to go forward. In retrospect, I should have inletted first, THEN gone to the scroll saw. At this point, I'm forced to fit the right side grip (because it has the least amount of material in the heel) first and that will dictate the left side's profile. I would have proceeded this way regardless, but I should have thought further ahead. I think my next move is to screw through the right side grip holes into the left and work some of the external dimensions as a whole unit. I've not yet figured out how to attach the left grip to the frame. The stock grip simply clips to the CO2 cartridge.

No, that's not dykem. It's just a silver magic marker. It shows up well under the sawdust as you're cutting.

The inside won't be so pretty. I used a 30,000 rpm trim router for this.

3/8" deep routing. Test fitting looks promising. I no longer wonder why Nill-Griffe gets $250 for a pair of these. You really need a milling machine to inlet something like this. http://www.nill-griffe.com/

For the most part, the right will dictate the left. A palm shelf will come last. One bolt slot for the shelf or 2? More to ponder. And yes, I cut myself with a razor knife while scoring the walnut so the router didn't rip the corner off.

Here's my valve volume increase. Inside the valve, the sleeve serves to provide a base for the o-ring (140-058) and valve seal (38-094) to seat against. Just make this into lattice. Of special note: It's working. The pellet holes are substantially cleaner as they cut through the 10 meter targets. If I take it apart again, I'll try drilling a few more holes-- or it'll be slotted. I tried hanging a piece of tissue over the cylinder and looked for CO2 leakage at the transfer port as well as at the cylinder gap to the breech. Let's just say I've never seen a revolver so tightly fitted that it still functioned. On one hand I'm happy I was able to virtually eliminate any wasted CO2. On the other hand, it's getting harder to find any more power. I think I need to revisit that valve spring and see just how weak it'll go and still function.

Now that the right grip has been inletted to fit the 38T's frame and the mounting screws have been located and drilled on the drill press, I've screwed the two halves together to shape the common sides.

I chucked a 2" diameter sanding drum into the drill press and dropped the rpm. If you try to go too fast, you'll just burn the wood's surface. This let me sand the top, front and base as one piece. It'll fit tighter together this way and help eliminate unsightly gaps at wood to wood junctures. I used a charcoal mask while sanding. Black walnut can be an irritant to many people when inhaled.

Time to inlet the left grip. I laid the gun's frame on top and traced. Scoring the line with a razor knife helps prevent the router from ripping out more wood than you intended to remove.

More scoring.

The trim router. Categorically the most dangerous shop tool I've ever used. 30,000 rpm helps keep the blade from tearing the wood. Whatever happens to the workpiece, do not under any circumstances let go of this tool. It will jack you up. It is extremely helpful from a control standpoint to get to full depth in several increasingly deeper passes. This tool is literally a wood eraser.

Anchor the work. Go slow and easy and you can write your name into the wood.

Test fit. The inletting is, to me, the worst part of the job. It's also, unfortunately, the important part because it defines how good the project will ultimately look. I am by no means good at this. I'm learning an awful lot as I go along. It helps that I have a few airguns with adjustable match grips to compare and pick the best features from. One of the challenges with a revolver is the bore height in relation to your grip. Getting your hand higher on the gun is better for recoil control as you get less torque from the muzzle blast. A non-issue here, but the lower sighting plane feels more natural. The "wing" at the top of the grip will be necessary once the adjustable palm shelf gets added later. The goal with a match grip is to envelope the hand and provide outstanding ergonomics for both sighting and control.

Back to the sanding drum. I used several smaller diameter drums to make the corners disappear and round the overall profile. Constant transfer to your gun hand ensures that it fits you. It's customary on the firing line to see match guns with wood putty, rasp marks and skateboard deck tape on the grips. Just making the tool fit.

Roughed to shape.

Left grip roughed to shape. Far less to do to this side.

Slightly further along on the right grip. The finger notches are starting to show more definition.

Derrick Works his Magic on a Crosman 38T, Part 2

Derrick's chronicle continues...

Left side: Original .177 cal pellet cylinder. Center rotation hole is 1/8" dia. Right side: Ebay purchased. Bored out for .20 cal pellets. Center hole is 13/64".

Need to either bore the original cylinder out to .20 cal or make a bushing for the replacement cylinder. I'll try the bushing route first.
First, I turned down a piece of round brass stock to fit the bored out cylinder.

Facing off a brass rod. Yeah, I know there's other tools for this. It was already in the tool post and it cuts like a laser beam. I made the tool to crown barrels.

A slightly blurry pic of the drill at work. Is there an easier way to drill holes in the center or round stock? Nyet.

Bushing installed. It was a snug fit to start, so I added a little super glue just for overkill. It's not going anywhere. The pin keeps it captive as there's not enough room for it to back out.

The 38T's new .20 cal barrel cut to final length and a target crown.

Oh dear God, what am I getting into? I've got minimal woodworking ability. Wait. I've just got minimal ability.

Everybody was kung-fu scroll sawing. It can (will) only go downhill from here. It was a perfectly good walnut board until I got hold of it.

Thick and chunky! You'd probably think I had a plan before I wasted $12 worth of walnut and precious time on a gun that doesn't shoot fast enough (yet) to cut clean scoring holes in a 10 meter target. Well, you'd think....

Derrick Works his Magic on a Crosman 38T, Part 1

Derrick, our Ohio correspondent, is at it again, modifying a Crosman 38T.

Self-centering. Not the stock cylinder. Ebay! Nobody named Derrick noticed the big hole in the middle of the cylinder till later. I had no idea that Crosman used two different cylinders in 38Ts. They both started as .177 cylinders. Just over 1/16" in hole diameter difference. This one is too loose on the pin. Need to turn a bushing later.

Brass Crosman SSP 250 barrel in .20 cal.

Holy cow! Udder madness. The inside of the shroud tapers? I think they were trying to put weight (metal) at the muzzle without using a heavy barrel. I bored the muzzle end out to 7/16"--to match the OD of the new barrel.

Taig time. Crowning the .20 cal bbl. Also cut the breech with a small taper to guide the pellet into the rifling. Notice that I re-faced my 3-jaw chuck faces. There was some kind of industrial accident that had previously rendered them "gouged". Also cleaned up the business ends.

I like the recessed target crown. It adds a bit of extra visual appeal for an extra minute or two of time. I've found that it's essential when finishing the crown's bevel to start from the center and work towards the outer edge. So many simple things that I have to figure out for myself. I'd never thought about how the metal pulls in the direction that you're cutting.

Groovy. The o-rings provide a press fit into the shroud's varying ID and effectively centers the barrel. 2 steps at the breech. I'm not sure why. I think I was going in a different design direction and made a change. The barrel is about 2" too long. Left extra length to allow fitting at the cylinder.

Much more to come...