Hudson H9 Review

Review of Hudson H9, sn: H043xx

First impressions:
The Hudson H9 appears to be very well made, with the kind of niceties of high-end firearms: an absence of sharp edges, and excellent fit and finish. It’s not as ugly as it looked in some of the photos.

Of course its claim to fame is that the recoil mechanism is in front of the trigger guard, rather than above it.  This, in theory, should reduce muzzle flip by getting the bore lower to axis of rotation (the shooter’s wrist).

Hudson H9

The Hudson H9 and three factory mags that came with it.

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Completing an “80%” 1911 frame.

A sort of odd byproduct of bizarre firearms laws is the “80% kit”. Just to be on the smart side, you should understand that “80%” has no meaning beyond “some of the work has been done for you”. From a legal perspective, a piece of metal either is a firearm, or isn’t. The U.S. government (BATFE) doesn’t recognize anything as being “80% complete” – they only acknowledge that some piece of metal has had insufficient work done to it to be considered a firearm.

In this article, I’ll go over the steps necessary to complete an “80%” 1911 frame from Tactical Machining. I purchased two of these kits and they seem to be a nicely machined start to a standard 1911. Of course it’s hard to know the true quality of the thing until it’s either been fully measured (not gonna happen!) or built.

The work to do looks to involve the following:
1. Cut the slide rails.
2. Cut the barrel seat.
3. Drill the hammer and sear/disconnector pin holes (and countersink).
4. Install the ejector.
5. Install the spring plunger tube.
6. A surprise bit of machining…

The ejector and spring plunger tube aren’t really part of the frame, but since they’re more or less permanent attachments, and each is relevant to this discussion, I’ll include them here.

This article will cover how I go about completing one of these, using a mill and none of the purpose-built fixtures sold for finishing a 1911.

I’ll start with steps one and two, as they can both be done on the mill in the same setup (position). Because this is a great project for someone relatively new to building firearms, I’ll try to include a little extra detail. In any manner of machining there are multiple ways to do something. This is only one, and may not be the best for you if your equipment is different. It’s the best I could come up with, given the tools I have.

Mount an angle plate to the mill table. This will provide a vertical surface on which to attach the frame-to-be. I dial the angle plate in just as I would align the vise, so that it’s face is closely parallel to the mill’s X-axis.

Clamp the piece to the face of the angle plate, using another plate to spread the load across the workpiece to avoid crushing any of its thin cross-sections. Be sure to clamp on parts of the plate that have part of the work under them. I’m going to use a level to get the piece close before refining the position. That only works if the mill table is level, so check that first.

I then use a Dial Test Indicator (DTI) and move back and forth across the piece until the top surface is level. As it gets close, I snug the clamps tighter. I like to use a two pound lead sinker to tap stuff around in clamps or the vise for alignment. It provides a dead blow and won’t mar most workpieces. Once it’s aligned and the clamps are tight, I measure yet again to make sure nothing has moved while clamping.

Next, I will find the sides of the piece, and therefore know the centerline.

My workpiece came in at 0.754″ wide, which is a neat 0.003″ larger than spec – just enough extra for fitting, if desired. So my centerline is at 0.377″.

The rail starts at 0.1″ below the top of the frame and is nominally 0.119″ ‘tall’. A good sanity check is that the cutter should be basically even with the dustcover at its lowest position. To start, I will find the top of the workpiece, with the bottom of the cutter. I use a piece of cigarette rolling paper. Being about 0.001″ thick it’s about as close as you can get without touching the workpiece. I’ll wet it with a little WD-40, so it’s not sticking up, and then slowly raise the mill table until the paper is moved by the cutter.

Here the paper has just kicked out from the cutter. I’ll move the work sideways, not disturbing the height adjustment, then move up a final 0.001″ to compensate for the paper thickness and zero the Z-axis (knee) dial. That established the position of the bottom of the cutter to the top of the work. I’m now going to dial on the distance to the _bottom_ of the rail. which is nominal 0.219″. Here’s where we can make the “sanity check” I mentioned before.

The next dimension to find is where the edge of the cutter is with respect to the rails-to-be. I’ve already established that this side of the frame is 0.754″ directly under the center of the spindle,so I just need to move away one-half the diameter of the cutter. My keyseat cutter has a 3/8″ diameter cutting surface, so I need to add half of that (3/16″ or 0.1875″) to the center position. (0.754″ + 0.1875″ = 0.9415″) I move the Y-axis to 0.9415″ and again make a sanity check, seeing that the cutter is right at the surface to be cut.

As I start cutting the rail, the previous number (0.9415″) will get smaller, so I should figure out the stopping point. On the drawing, the width from the inside of the rails should be 0.628″. Taking the full width of the piece (0.754″) and subtracting the width between the rails (0.628″) gives 0.126″ so each rail needs to be cut to half that depth, or 0.063″ (basically 1/16″). Since I’m starting at 0.9415, I’ll want to cut until my Y axis reads (0.9415″ – 0.063″) 0.8785″.

Because the X-axis cut goes all the way through left-to-right, I don’t have to establish a position in that direction, so we’re ready to cut! I’ll apply some cutting oil, advance the cutter about 0.005″ for a first look and conventional-mill the length. That looks pretty good.

You might have noticed that the pin hole for the ejector isn’t centered in the slot, but don’t worry! This cutter isn’t cutting the full height of the slot, so the slot is not as tall is it will be when It’s done.

From here it’s just a matter of backing the cutter out, returning to our starting position, adding some depth to the cut and repeating the process until we’ve reached the target depth of 0.063″.

Now it’s time to open up the slot to full height. I’ll back out back to 0.9415″, where I started last time, and, since my cutter is 0.1″ tall, I’ll move up 0.019″ and repeat the process to get a full-height slot.

Note that the ejector roll pin now looks correct.

Now I’ll prep to do the same thing on the backside. Since the cutter is already at the high side of the slot, I’ll cut that first, then move down 0.019″ to finish. But first, I need to calculate the starting and ending points for depth of cut on the backside. The backside is at 0.000″, so at -0.1875″ the cutter is even with the back.

Having “completed” the rails, I’ll make some measurements to verify that everything came out as expected. Any time you break a setup, or change tools, you lose some information. In this case, I’d lose the Z height reference if I were to swap tools. You could find it again, but every time you do, you introduce tolerance. So, I check everything I can before removing the key-seat cutter.

Once I’ve determined that there is no more to do with the keyseat cutter, I switch to an 18mm center-cutting ball endmill. This is how I’ll cut the barrel seat. In combing a half-dozen “blueprints” for the 1911, I was unable to ascertain with any great certainty how deep to cut. I _was_ able to ascertain that there are some completely incorrect “blueprints” out there… Having looked at multiple prints and measuring a few complete 1911s, I decided on a depth of 0.075″. The 18mm ball endmill that I’m using is a little off the spec’d diameter, butI think it should work. I set the mill to 0.377 (my centerline) and, again, used a cigarette paper to find the Z-height. From there, it’s just a matter of cutting ‘down’ 0.75″ across the portion of the workpiece from the mag well forward.

On the first pass, you can check that you’re centered, then it’s an easy few swipes to complete.

If you’ve mounted your frame with foresight, you can now try on a slide to see if it fits. Before doing so, a good cleaning, and a light pass with a file along the rails until they feel smooth and burr-free should be performed. Here’s my frame, with the ‘slide’ (actually a .22 conversion kit) that I will use with it.

The last major operation expected is to drill the hammer and sear/disconnector holes. Both holes are referenced from the slide-stop hole, with their respective positions being:

Hammer pin: (2.973″, 0.016″) 0.158″ dia. with a 0.020″ countersink.
Sear pin: (2.602″, -0.252″) 0.110″ dia. with a 0.020″ countersink.

I used a pretty cheesy fixture for this, using the top deck of the frame for a reference against the fixed vise jaw and a piece of furring strip on the bottom to handle the irregular surface at the bottom of the handle. This was sufficient for drilling, but a better setup would probably be to clamp the frame down on a flat plate, leaving the area to be drilled hanging out so as to be able to observe the drill going through.

I dialed in on the take-down pin hole. I used a Co-Ax indicator, but any kind of hole locating technique should work. I set the X and Y axis for zero (0,0) and since we’re drilling, there’s no need to account for cutter radii.

I first moved to the sear/disconnector pin location and spotted it with a spotting drill after visually verifying that the location appeared correct.

I then drilled the hole just undersize, then crept up on the final diameter using wire-gauge (“number”) drills. If you try to drill to size in one pass, your drill will probably cut oversize and ruin the workpiece.

Finally, I finished the hole with a 60* countersink. I’m using a “combination drill and countersink” for the operation. Be sure to use one with a drill portion that is smaller than the hole you are countersinking. I used this because my other countersinks, and most common countersinks, are 82* but these are 60* as called for by the prints.

To cut the countersink, I run the cutter down until it is in contact with the work. Then I zero the knee on the mill, back it off a little (so I’m not starting in contact with the work), then crank the knee up 0.020″. A quick test fit of the pin looks great.

I repeated the same process with the hammer pin, this time using metric drills, with similar excellent results.

In theory, that’s all the machining that should be required, but I found one more bit, which I’ll discuss in a moment. But first, adding the two parts that are pretty much permanent attachments to the frame: the ejector and the spring plunger tube.

I didn’t take any pictures of installing the ejector, because it’s very simple – insert the ejector and pin it in place with a 1/16″ roll pin. I did want to mention though, that this pin is actually much easier to install if you do so before machining the rails. It’s easy to mash up the head of a roll pin if you’re careless, and even easier if it’s in the trough of the slide rail. Install it before machining, and you’ll have a perfectly flush pin end, every time.

The spring plunger tube, I have much to say about. As a high-volume 1911 shooter, this part is responsible for the one serious mechanical malfunction I have experienced: having the plunger tube come un-staked. In my case, the rear (closest to the thumb safety) came loose and the tube cocked out a little bit, locking the safety in the ‘safe’ position. Since then, I do plunger tubes a little differently than most. The generally accepted method of install is to drop the plunger tube in place (making sure the right end is pointing forward (hint: look at the square take-down slot on the frame, the plunger tube shouldn’t overlap it.) and then stake the ‘legs’ in place using some manner of staking tool.

I like to solder mine in place, then stake it. This belt-and-suspenders approach has never failed me.

I start by setting the plunger tube in place, then tracing the outline with a scribe.

I then sand the inscribed area as well as the bottom of the spring plunger tube so the solder will adhere. (Sorry the sanded portion on the frame didn’t photograph well…)
Next, I degreased both surfaced with acetone, then clamped them together with a small (heat-proof) spring clip.

I then liberally coat the surface with soot (carbon). I used an oxy-acetylene torch, with just an acetylene flame, but you could also use a candle, or a little burning masking tape.

The reason for the soot is that it will prevent solder from flowing where we do not want it. Removing the spring plunger tube with a pair of tweezers, I have a nice, crisp clean area.

Looks like I missed a picture, but I carefully dabbed solder flux in the area to be soldered, using the wood end of a cotton swab, then cut off a small piece of solder (about 3/32″ long) and stuck it in place, letting the flux hold it. I carefully replaced the plunger tube and re-clamped with the spring clamp. I used Brownell’s “Hi-Force 44” because it’s a nice low-temp solder and I don’t want to change the temper of the frame. A bit of heat with a MAPP torch accompanied by a slight jostling of the plunger tube and the whole thing collapses neatly into place.

And here’s a better view after wiping off most of the carbon. The plunger tube is soldered permanently in place and there is no solder visible.

Finally, I’ll stake it in place as is normally the case. I use a kit composed of a filler rod to prevent the tube from crushing, a ‘pad’ to distribute pressure across the plunger tube, and a pair of modified vise-grips with a point in the moving jaw to peen the hollow ends of the plunger tube legs.

It should be mentioned that there is a disadvantage to my method: Solder does not do well in a hot blue solution. The solution may eat away at the solder, and the solder may contaminate the bluing solution, resulting in a poor finish. I have no intention of bluing this frame, but if I did, I would either forego soldering, or do it (carefully!) after bluing…

And a surprise…

While test-fitting individual pieces I discovered that the thumb safety could not be installed in the bare frame. The problem is the frame thickness in the area where the safety stud inserts. The wall thickness must be thin enough to clear the notch on the safety.

Examining the frame, a small step can be seen in the area. No such step exists on the working 1911 frame with which I compared it. measuring across the gap, the 80% frame is thicker. Finally, trying a safety from a working 1911, it did not fit either. This is pretty overwhelming evidence that the problem is with the frame.

Standard advice when fitting two pieces is “Modify the cheaper part”, which in this case would be the safety. And it would be possible to modify the safety, but that would be a point of fitment that I have never seen, meaning this frame would always require a non-standard part. Given this consideration, I decided to modify the frame instead. This might seem like a difficult cut, but with a tiny keyseat cutter (mine is 1/4″cutter dia, 0.035″ thick) this should be a pretty easy operation.

I clamped the frame to a 1911-specific bench block and held it in the vise. For this cut, no external alignment is necessary as I’m just going to ‘clean out’ all of the area I can reach through the hole with my cutter. The two important things about clamping for this cut are to leave enough room for the mill spindle to move through the cut without hitting the clamp, and also leave enough room to test-fit the safety.

Next I aligned the cutter with the ‘center’ of the tri-lobular safety cut, finding the location where a 1/4″ diameter cutter could pass through without interference. I called this (0,0).

Next I’ll find the top of the frame with respect to the bottom of the tool, using a piece of cigarette rolling paper, as previously described.

I want a finished thickness of 0.067″ (which I arrived at by measuring my ‘good’ frame.) So I’ll move the knee up 0.067″ plus the thickness of the cutter (0.035″) or 0.102″. (Note, that’s “knee up”, which is equivalent to “cutter down”.)

Finally, I’ll move the shank of the cutter into either end of the tri-lobular cut and a toward the front of the frame.

Retract the cutter and test the safety… (Note safety in previously-unachievable ‘off’ position.)

It works! But just barely. I might cut a thou. or two thinner next time.

That’s it for the work on the frame. Quickly throwing it together (well, and fitting the thumb safety), I put 10 rounds through it without a hitch, indicating that there’s nothing seriously wrong. The thumb safety is a bit tight, so I may work on that a little more at some point, but probably not until I’ve put a few hundred rounds through it to break it in, and make sure there’s nothing else I want to modify before putting a finish on it.

Happy shooting!


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Rust Prevention: Testing Corrosion Inhibitors

There are a few really good tests of rust protection on the web. I thought
I’d try a smaller study with some of the “winners” from those tests as well as
a few I had laying around. I cut out individual coupons of mild steel and
sanded them bright.


Rust prevention products


Next each piece was degreased with acetone. Gloves were worn for degreasing,
and from that point on, no hands will touch the test coupons.

Each piece was then coated with a different rust preventative. Coatings were
applied by saturating a patch with the preservative, then wiping it on the
coupon. A new set of gloves and patch were used with each preservative, so
there is no cross-contamination.

The pieces will now undergo cycles of exposure to the elements and periods in
my mostly unheated shop. (A few degrees warmer than outside and dry.) To
start with the coupons were left in the rain for 15 minutes.

A bare steel coupon was added about 20 minutes late, so it’s receiving
near-identical treatment, but not in time for the pics.

The pieces will remain on a shop towel, which will preserve moisture. At some
point I will check the backsides as well, but for now we’ll just monitor the

Preservatives under test are:

CRC 350
CRC 400
LPS 23
Renaissance Wax
EWL (Enhanced Weapons Lube – coupon marked “AWL” – oops!)
Lucas Gun Oil
Weapon Shield
Eezox (winner of one on-line test)
Hornady One-Shot (winner of the most comprehensive-appearing online test)

Grading will be as objective as I can make it. Certainly there will be a
definitive 100% for a coupon exhibiting no rust. The first bit of genuine
(orange) rust will eliminate a “competitor”.

The following chronicles some of the events, and my reactions as they occured.
I’m trying to keep it brief, but there were a few surprises, and much
learning, for me.

Ren Wax starts to fail
I had anticipated that the waxy compounds would be impervious to moisture, so
it was with considerable surprise that I observed that Renaissance Wax was the
first coupon to exhibit rust. Even before the untreated metal. This would
seem to imply some randomness as to what rusts, even under conditions as
identical as I could make them. Another theory might be that something in Ren
Wax causes rusting under these conditions, but I am not inclined to believe
that. It could also be a matter of application, but I was pretty careful and
if application played a role, then it would likely do so in practical use as
well. Further, if the rust had appeared only at the edge of the coupon (where
application might be more of an issue) I might consider the result somewhat
skewed, but rust is forming well inside the boundary. At this point, the rust
is light.

Eventually the untreated piece starts to rust, by which time the Ren Wax piece
is well endowed with rust. If you’re noticing the spot on the SP400 coupon,
you might think that’s rust, but it’s a bit of leaf or something.

Again to my surprise (since it had done so well in someone else’s online test)
the Hornady One-Shot was the next to succumb to corrosion.

Here’s the test at 26 days. That’s Ren Wax rusting away at third from the
left in the top row. In the middle of the second row Lucas Gun Oil has sadly
been defeated (I really like this as a lube, and hoped it would do better.)
In the third row, Hornady is racing to corrode as badly as Ren Wax and the
bare steel. The others are (kinda*) unaffected.

At this point you may have noticed a ‘tinge’, a hint of corrosion on some of
the pieces that I have not counted out. This was not at all obvious to the
naked eye, but certainly came to light in many of my photos (if only I’d
looked at them sooner!) as well as when examining under magnification. I
wasn’t paying close enough attention this time ’round to take note of that in
a ‘fair’ way, so I’m discounting it here, but it certainly informs me of what
to look for in my next rust test. For now, we’re only comparing ‘orange’

Another surprise was how well Ballistol held up. I didn’t expect much (I
couldn’t tell you why I had low expectations), but it finally succumbed on day

In the final assessment, here’s the ‘top’ view. Bare steel, Ren Wax, Hornady
One-Shot, and Lucas Gun Oil all gave in. Ballistol did as well, but to a much
lesser extent.

Weaponshield, EWL, and Eezox all held up pretty well, but exhibited that
tell-tale “pre-rust” that I’m not really counting.

The CRC SP350 and SP400 and LPS-3 all looked ‘perfect’ on top.

Then it was time to flip them over, and see how the side in relatively
constant contact with moisture did…

Bare steel failed horribly. Ren Wax faired a little better than One-Shot,
Lucas Gun Oil did a little better. Ballistol wasn’t great, but wasn’t the
loser, and Eezox did pretty well.

Weapon Shield and EWL were pretty much failures on the backside.

In a final bit of distinction, the CRC SP-350 failed, though not as bad as
most, while the SP-400 was a standout in being seemingly impervious to

The LPS-3 came in second, but it had some corrosion starting.

I’m going to chalk this up as a data point, but the biggest lesson, to me, was
probably in how to better test rust prevention next time. (And, yes, there’s
a “next time” in the works.)

First, I think vertically orienting the samples will help to show what
‘creeps’ and what doesn’t. Second, I need to accelerate the test or this will
take months. Third, I need to inspect more closely. The “pre-rust” marks which
should be accounted for, but accounted for differently than “full rust”. I
say this because I think I noticed a difference in the amount of time it took
some of the samples to develop “full rust” after demonstrating “pre rust”. So
although neither are desirable, I think it’s valid to say that something that
delays “full rust” longer than another thing is a better corrosion inhibitor.

It’s also worth noting which compounds are lubricants and which are
exclusively corrosion inhibitors.


My first recommendation is that you run a test yourself! The more the
merrier, and the more data we gunowners have, the better we can decide what to

For my part, and for the moment, I’ll be using CRC-SP400 for all the places
that don’t get handled or require lubricity (e.g. metal under the stock) as
well as for long-term storage.

I like Ballistol for its low odor and low toxicity, so I’ll probably use that
on my regular use firearms, even though it wasn’t the top performer.

I haven’t tried EWL, Eezox, or WeaponShield on any of my firearms for use, but
each have earned a trial, so I will be using them in the future. I’m probably
going to try out SP-350 as a lube as well. (SP-350 is lubricious, SP-400 is

I’ll be testing all of these again, but for the time being I won’t be using
Rennaisance Wax, Hornady One-Shot, or Lucas Gun Oil for corrosion protection.
(Which is a crying shame, because I have had some indication that Lucas was a
superior lubricant to those that I have tried.)

All of that leads to a reminder: this is only a test of corrosion resistance.
I made no attempt to judge lubricity, cost, attraction of dirt, or anything
other than corrosion resistance, so it would be very premature to say that X
is better than Y in general. If I lived in Arizona (someday!) I might be
judging these by a quite different standard. Make sure your choices match
your needs.



Posted in Firearms Maintenance | 3 Comments

Three Gauges

Taken from the book Centrefire Rifle Accuracy which I have previously reviewed, here are three gauges useful to any reloader, but particularly to a reloader who has chambered his or her own barrel.

The first is a full case gauge.

Case gauge (cutaway chamber)This is made by cutting a full-length chamber, ideally with the same reamer that was used in your barrel, in a piece of barrel scrap.

With this gauge, you can see the fit of your brass and bullet.  It’s also an opportunity to grade your chambering setup as you can see the cut of the rifling lands.  The gauge shown is a 6.5mm Grendel.

Case inserted into case gaugeHere’s a factory round inserted into the case gauge.  Right away you can see that there’s ample trim-length (case OAL) left, and you can get an idea of how far the bullet is from engaging the lands.

Next is a shoulder set-back gauge.  This gauge is used to measure the distance from the base of the brass, to the shoulder datum.  You can measure cases fired in your chamber and set your sizing die to only bump the shoulder back as much as necessary for your rifle.  To make, simply ream a bit of barrel deep enough to cut the case shoulder profile, but not into the body.  (If you cut part of the body, you can always face it off.)

Gauge for measuring length to shoulder datum.The final gauge is barrel and bullet specific, though mostly bullet (the variations in barrels are small by comparison).  It is a seating gauge.  To make one you cut about neck-deep using your chamber reamer, then trim the other end such that it is 0.100″ longer than the tip of the bullet.  In this way you have an COAL gauge that can be used to measure nominal COAL by measuring across the base of the cartridge and the gauge, then subracting 0.100″.  This avoids the small, but annoying inconsistencies of measuring across non-uniform tips.   This measurement is also much more meaningful as it is closer to answering the question “How far is my bullet from the lands in _my_ barrel?”.

Bullet seating gauge

So here are all three gauges – a veritable cornucopia of information for the reloader who wants to control everything.

The full gauge set




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Installing flush-mount sling swivel cups

Today I’m going to install three flush-mount sling swivel cups in a Bell &
Carlson stock for my Remington 700. Three because I want to use a Ching sling
with this rifle and flush cups because I’d like a smooth surface when shooting
over any kind of rest.

I have quite a bit of work planned for this stock, but we’ll start simply.
The sling swivels I purchased are Grovtec threaded cups, made right here in Oregon.
They install with a 9/16-18 tap, so I bought a cheap, carbon steel tap as

Additionally, a little Devcon Steel Putty, some mixing sticks and we’re ready
to go.
Sling installation materials Continue reading

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