Glock 17 Magazine Block

The Glock 17 usually comes with a 17 round magazine.  Well, in New Jersey you are limited to a maximum of 15 rounds.  Since NJ is the only state with that odd number as a limit, 15 round magazines are difficult to find for any firearm.  As a result, the Glock 17 ships with 10 round magazines in NJ.  Now I can live with giving up 2 rounds, but not 7!  Nobody makes a 15 round magazine for the Glock 17 (and no, the 15 round Glock 19 magazine does not fit the Glock 17).  So, I designed this magazine block to limit the standard 17 round magazine to a maximum of 15 rounds .

Magazine Block

The block fits between the floor plate and the magazine insert; keeping the internal design of the magazine unchanged.  Magazine function and reliability are completely unaffected.

Here is how to legally convert a 17 round Glock 17 magazine to hold 15 rounds.  All of this must take place in a state where 17 round magazines are legal.

1.  Go to Shapeways and order the magazine block.

2.  Get yourself some epoxy.  I use JB Weld.  Crazy Glue won't cut it; it is too easy to pull the pieces apart.

3.  Drive to a free state and purchase a 17 round Glock 17 magazine.  Bring the block and epoxy with you.

4.  While still in a free state, disassemble the magazine.  Check to make sure the block fits in your magazine. It should be a tight fit.

5.  Swab the inside of the magazine, insert, base plate, and block with alcohol to remove any oil and/or dirt.

6.  Apply epoxy to the bottom of the magazine insert and set it on the magazine block.

7.  Apply epoxy to the sides of the magazine block and slide it in place.  Make sure not to insert it too far.

8.  Apply epoxy to the bottom of the magazine block and slide the base plate back on.  (It may be necessary to load 15 rounds to fully seat the magazine block down against the base plate.)

9.  Wipe off excess epoxy.  Keep the magazine vertical so that any excess epoxy runs down towards the base plate, not into the magazine.  Stay in the free state until the epoxy sets!

10.  Return home and enjoy 50% more ammo in your Glock 17.

Now the magazine is permanently converted to 15 rounds.  I am not an attorney, but according to attorney and firearms law expert Evan Nappen a blocked large capacity magazine is legal "as long as it is permanently blocked".  By epoxying all of the parts together you cannot take the magazine apart and convert it back to 17 rounds without destroying it.  DO NOT INSERT THE BLOCK WITHOUT EPOXYING IT IN!!!  That is not permanent.  You will be in possession of a banned magazine; committing a fourth degree crime punishable by up to 18 months in jail and a fine of $10,000.

Click here to order.

High Standard Recoil Pad

new recoil pad installed

The original recoil pad on this High Standard Flite King shotgun was dry rotted and rock hard. It made for some pretty uncomfortable shooting. I could not find a High Standard replacement piece, so I ordered a Pachmayr #325 Deluxe Skeet replacement pad. It's not an exact match but the Pachmayr pad resembles the original.

original recoil pad

The details of the installation are the same as in this post. This time however, I remembered to follow the angle of the toe line on the stock. This pad was a little tricky to install because the vertical lines on the pad exaggerate any uneven sanding on the pad. The pad will look off-center unless each side of the pad is shaped exactly the same.

vertical lines require careful shaping

proper toe angle

The fit came out nearly perfect, nice and flush to the stock. The Pachmayr pad is nice and soft, recoil will not be an issue. This shotgun is ready to return to the field.

pad is even with stock

Hammerli 850 Cheek Rest

elevated cheek rest

Lately I've been busy improving my Hammerli 850 air rifle.  With the new trigger job, this rifle is quickly becoming one of my favorites.  The next problem to tackle is the height of the cheekpiece on the stock.  It is too low for my scope.  For best accuracy your cheek should be pressed firmly against the stock with your eye perfectly centered in the eyepiece.  To see through my scope, I must lift my cheek off of the stock.  Not comfortable and bad for accuracy.  Good target stocks will have an adjustable cheek piece.  If this were a wooden stock, I could just cut it and install a mechanism to raise it.  Not so easy with a hollow plastic stock; so I decided to make a new cheek rest.

kydex formed to stock

I purchased a sheet of kydex  from Amazon.  I went with a thick piece (0.118") for the extra strength.  Next I cut the kydex sheet in half (6" x 12") with a pair of sheet metal shears.  Then I preheated the oven to 350 degrees and placed the kydex in a Pyrex dish for three minutes.  I checked the sheet with a spatula to make sure it was very pliable.  Then I scooped it up and placed it on the stock folding it over the cheek piece with gloved hands.  I quickly got the alignment just right and held the kydex tight against the stock as it cooled.  In about 5 minutes the kydex had cooled and was rigid.  It formed perfectly to the shape of the stock and the pattern and color even matched the stock.

tracing the pattern

To make a pattern, I wrapped a piece of paper over the stock.  Then I traced the edges of the cheek swell with a scrap of aluminum sheet.  The aluminum worked really well, cleanly marking only the edge.  I carefully cut the pattern out with an x-acto knife.  I placed it back on the stock and drew some witness marks on the paper and stock so I could lines things up later.  Finally, I cut the pattern in half.

spacer taped to stock

The next step was finding the correct height for the new cheek rest.  I experimented by placing pieces of rod under the cheek rest until my eye was perfectly aligned with the scope.  Turns out a 1" rod and a Bic pen tube provided the perfect height (1.319").  I taped the spacer to the stock and put the kydex over it to test.  Perfect.  Now to make the bottom of the new cheek rest match the contour of the stock.  I coated the back of the pattern pieces with spray glue.  Then using the witness marks, I lined each pattern up on the stock and stuck them to the kydex.

hlaf of pattern glued to kydex

The bulk the excess kydex was trimmed away with the metal shears.  Then the kydex was formed exactly to the pattern on the belt sander.  Now to attach the new cheek rest to the stock.  I was going to make the cheek rest adjustable by cutting slots in the kydex but why bother?  I only needed to set it correctly one time.  And most adjustable cheek rests have large ugly knobs on one side to tighten the bolts.  I wanted a cleaner look.  So I carefully laid out the position of the screws and drilled two 3/32" pilot holes through the kydex and into the stock on each side.  I then opened up the holes on the kydex to 13/64" and countersunk them so the screws would sit flush.  I enlarged the holes in the stock to #25 and tapped them for 10-24 screws.  Although the stock is hollow, it is thick enough where the cheek rest is providing plenty of threads.

screw holes in kydex

The pattern peeled off the kydex rather easily and I cleaned up any residual glue with Goo Gone.  I cleaned up any uneven spots on the belt sander and dressed the edges with 220 grit sandpaper.  Finally I screwed the new cheek rest to the stock with stainless flat head socket cap screws.  I was going to back up the screws with nuts but the plastic held the screws tight.  I added a drop of thread lock to each screw just to be sure.

finished and installed

height relative to scope

The new cheek rest is great.  It looks like a factory accessory and is rock solid.  Now that I don't have to move my head around looking for the eyepiece, I can get on target much faster.

PS - If you are cutting kydex on a scroll saw, I found that a 15 tpi blade at 500 rpm gave a very clean cut.  No melting and minimal saw marks.

Hammerli 850 Trigger Job

The Hammerli 850 is a great air rifle nearly ruined by a god-awful trigger.  Previously I posted about making a steel trigger for this rifle.  That was all about personal preference; it did nothing to improve the trigger pull.  The stock trigger pull isn't that heavy, it breaks at a reasonable 2.25 lbs.  But the pull is a very long and very mushy single stage that feels much heavier.  Mine was adjusted with no pre-travel, followed by 4 mm of movement that felt like you were pulling the trigger through chewing gum, and then another 11 mm of over-travel after the sear released.  There was absolutely no indication when the sear would release making the trigger very unpredictable and distracting.  And the over-travel essentially guaranteed that you jerked the trigger every time.  There is a useless adjustment screw but it only changes the amount of pre-travel.  It does nothing to change the pull weight or length of pull.  Time to work on the trigger.


Manual Safety

Before I worked on the trigger I had to do something about the safety.  It automatically engages whenever the gun is cocked.  This is not only a nuisance, but it breeds bad habits.  Engaging the safety should be a conscious decision.  Since 99.9% of the guns in the world have manual safeties, you do not want to get into the habit of assuming the safety will engage by itself.

Part that needs to be removed

Luckily this is an easy fix.  The safety block has a plastic tab that the bolt pushes on when cocking the gun.  Simply cut off the tab and you have a manual safety.

before

after

As an added bonus the bolt operates a bit more smoothly now without having to push on the safety.  Now to do something about that trigger.


Over-travel Adjustment

The worst aspect of the trigger is the over-travel.  Eleven millimeters may not sound like much, but it's huge!  To eliminate the over-travel I added a screw that limits the movement of the sear.  I drilled and tapped a hole for a 5-40 screw right where the sear spring is located.  I cut the head off the screw to make a threaded rod.  Then I carefully ground off a little bit of the screw and tested the trigger.  I repeated the grinding and testing until all of the over-travel was removed.  Then I used some Loctite to secure the screw in place.  I ended up with the screw protruding 5.5 mm above the sear.

screw added to sear

Adding a Second Stage

As I mentioned, there is 4 mm of movement needed to trip the sear.  Unfortunately, much of that movement is the sear pushing the hammer back against the hammer spring.  That accounts for most of the pull weight and trigger creep.  There is nothing that can be done about that unless you are willing to change the geometry of the sear and hammer faces.  Since they are die-cast in soft metal I didn't feel comfortable messing with that.  Luckily, someone came up with a way to add a second stage to the trigger.  What this does is, it allows you to put most of the pull weight and "mush" into the first stage, then just a little more movement is needed to trip the sear in the second stage.

I checked my supplies and found a length of 2.36 mm stainless steel drill rod.  I cut it to length and just placed in under the trigger to test it out.  It looked like it would work so I cleaned the parts in acetone and epoxied the rod to the trigger with PC7.

rod epoxied to trigger

During reassembly I burnished some molybdenum into the trigger and sear contact points and oiled the pivot pins.  The results were amazing.  Now the trigger pull is as follows.  There is no pre-travel, a very smooth 5 mm pull through the first stage, followed by a definitive stop before the second stage, then < 1 mm of movement to trip the sear with absolutely no over-travel.  Pull weight is now just 1 pound.

the finished trigger and sear

The original adjustment screw now determines how much of the trigger movement is in the second stage.  Turn the screw all the way in and you end up with a long second stage pull.  Turn the screw out and you transfer the trigger movement to the first stage.  Turn it out far enough and the sear trips in the first stage, giving you a single stage trigger again.  I have mine adjusted with the screw about one and a quarter turns out.

The trigger is so much better it makes the rifle much more enjoyable to shoot.  Now I can concentrate on the sights and not lose focus wondering when the gun is going to fire.  Don't get me wrong.  This is no match trigger, but I certainly can't blame any bad shots on the trigger anymore.

Salvaging a Marlin 336 - Part I

Marlin 336 (or at least it used to be)

A friend of mine found a bunch of old guns in an abandoned barn. Most of them looked like they had been in a fire then left outside for several years. Among them was a 1958 Marlin 336 in .35 Remington. I have always wanted a lever gun and this hot mess looked like just my kind of project. So we worked out a deal; my labor on the other guns in exchange for the lever action. The metal is rusty, pitted and charred from the fire.  The action is frozen. Stock is missing. The barrel is filled with crud. Lets see if I can bring this old classic back from the dead.

Right side.  Not pretty.

Left side.  Ugh, maybe this wasn't such a good idea.

First I drowned the entire gun in Liquid Wrench to hopefully free all of the screws. I let is sit for a few minutes and then tried to coax the action open with a rubber mallet and block of wood. No dice. Another soaking with penetrant inside the action, wait a few minutes, and we are ready to roll.

Surprisingly all of the screws came out pretty easily with the exception of the tang screw. That required some heat from a blow torch, some more Liquid Wrench, and some leverage. I ended up using a ratchet with my screwdriver bit in a 1/4" socket to get it moving. After that I was able to remove all the parts except for the bolt. That was stuck tight. So I inserted a brass rod down the barrel against the bolt face and gave it a few good whacks with a hammer. It finally started to move and I was able to push it out of the receiver. The bolt came out unscathed. The barrel unscrewed without any problem.

ready for cleaning

With everything apart I threw whatever fit into my ultrasonic cleaner with a 50% solution of Simple Green. I ran it for two heated cycles of 8 minutes each. That removed all of the crud and loose rust. For the barrel, I ran a brass bore brush through it while one end of the barrel was submerged in the Simple Green solution. Half of the barrel is actually in pretty good shape but I can feel two rusty patches in there. We'll see if I can polish those out. I hope so because, some preliminary Googling tells me that finding a new barrel isn't going to be easy. After the cleaning I sprayed everything down with a heavy coat of Ballistol and let it soak in. The parts were now clean but still ugly. Luckily it looks like most of the internals are in pretty good shape. They should clean up easily. But the receiver is going to take some serious elbow grease to make presentable.

cleaned and lubed

With everything cleaned, I took inventory and evaluated the parts. The mainspring and mainspring plate are missing. All of the springs have to be replaced. The magazine tube is bent and should probably be replaced. And there is no stock. For what this project is going to cost me in time and money I could probably buy a nice used 336 ready to shoot. But where's the fun in that? Before I drop any money on this thing, let's see if I can get the receiver back into shape. Stay tuned.

Hammerli 850 Trigger Upgrade

Original plastic trigger on left, new metal trigger on right.

Here is a project I did back in June 2008.  One of my favorite airguns is the Hammerli 850 AirMagnum.  It is a .22 caliber CO2 powered bolt action air rifle.  It holds 8 pellets in a rotary clip, has good power, and it relatively accurate.  Best of all, it is powered by an Airsource cylinder and can get around 200 shots per cylinder.

Hammerli 850 AirMagnum

While plastic stocks do not bother me, plastic triggers do.  I don't know why, it just makes the whole gun feel cheap.  So I decided to make a metal replacement trigger.  Not much to show for the build pictures. I just started with a piece of metal that was the right thickness, scribed the outline of the original trigger on it, and carefully ground, cut, milled, and filed, away the excess material down to the scribe marks.  I finished it up by polishing it with some emery paper followed by the buffing wheel on my Dremel.

left side

right side

front view (notice narrower profile of new trigger)

after bluing

I narrowed the trigger a bit to my liking.  After sanding and polishing I blued the trigger with some Berchwood Casey Perma Blue.  The new trigger works great and feels even better.

High Standard Thumb Saver

High Standard Thumb Saver

About a month ago I made a magazine catch for my High Standard Supermatic Trophy pistol by hand.  It worked well enough that I thought other High Standard owners might be interested in it.  So I decided to look into having my Thumb Saver mass produced.

I drew up a CAD model and submitted it to a plastics manufacturer to see about having the part injection molded.  While the cost per part was very low, the set up costs for making the dies was prohibitive.  I didn't think I could sell enough to ever recoup my expenses.  Plan B was to have the part 3D printed.  The cost per part is higher, but there are no set up costs.

So, I optimized the CAD model for 3D printing and ordered a sample.  I redesigned the part a few times to increase strength and minimize volume.  A few tweaks and a few samples later, I had what I was looking for.

Too small!

Note to self: check measurements carefully.  My CAD file was in centimeters.  The printing service defaulted to millimeters.  The first prototypes were just a little too small.

too weak

I had to find the right printing process with the right material.  Some plastics are too weak for anything beyond a prototype.

Too thin.

The next version was better but I felt a few areas were too thin.  So I beefed them up for greater strength.  I also removed material where it wasn't needed.

just right

rear view

The final part is printed in nylon; strong but flexible.  I think it should provide years of reliable service.  I use it  every time I shoot; it makes loading so much easier and faster.  This one is designed for the military grip models.  If there is enough interest, I may make one for the slant grip models as well.  If you would like one for your High Standard, the Thumb Saver can be ordered here.

Custom Ruger 10/22 Part IV - Troubleshooting

This was supposed to be a 5 shot group!

I finally made it out to the range to test out the custom Ruger 10/22 I built.  I just couldn't wait to see how accurate the rifle was.  Unfortunately, I never got to test the accuracy.  As soon as I started shooting, I experienced an unusually high rate of failure to fire (FTF) malfunctions.  A failure to fire is when a round is loaded into the chamber properly, the hammer drops, but the round doesn't go off.  Now it isn't unusual to get a few bad .22 rounds in a batch that won't fire, especially with bulk ammo.  But my FTF rate was about 44%, regardless of the brand of ammo!  Obviously something else was wrong.

I inspected some of the FTF rounds and noticed that the primer strike looked light.  In fact on some of the cases, it looked like the firing pin just barely nicked the outer rim of the case.  Since each round was feeding perfectly, and the bolt always closed completely, I thought the firing pin might be the problem.

I used the depth gauge on my digital calipers to measure the firing pin protrusion.  It measured 0.018".  It should be about 0.035".  The bottom of the pin also seemed to be rounded over, almost like it had been dropped or dry fired a lot.  Maybe I found the problem?  So I ordered a custom firing pin from KIDD Innovative Design.  It was specifically designed to address inconsistent ignition.

Stock Ruger firing pin in front of KIDD firing pin.  Notice the KIDD pin is longer.

The new pin was beautiful.  Well as beautiful as a piece of metal can be.  The extra quality of the KIDD pin  is plainly evident.  Installation was very easy, took just a few minutes.  With the new pin in, I measured the firing pin protrusion to be 0.036".  Much better.

After I reassembled the rifle, I loaded up a few plastic snap caps and pulled the trigger.  Rather than the rounded little dimples the original firing pin left, the new pin left a long, deep, well defined dent.  As long as it doesn't pierce the case rim, I think we're in business.  Only one thing left to do; get out to the range and shoot!

3 strikes from the old firing pin and one from the new pin.
I'll give you one guess which dent is from the new pin!

At the range I tested out some CCI Standard Velocity, CCI AR Tactical bulk, and Remington Thunderbolt bulk.  Without any regard for accuracy I just squeezed off 10 rounds in rapid succession, swapped mags, and continued until I had fired 100 rounds.

Here are the results.
CCI Standard Velocity: 10 shots, zero FTF
CCI AR Tactical: 30 shots, 2 FTF
Remington Thunderbolt: 60 shots, 3 FTF

Note that all FTFs were with bulk ammo.  Each FTF round fired when I loaded it back in the magazine and tried to reshoot it.  So, I went from a 44% FTF rate to a 5% FTF rate.  Much better and par for the course I suspect with bulk ammo.  I am guessing higher quality ammo will function 100%.  Problem solved.  Now to test for accuracy.

At the range.