Shall Not Be Questioned » Gun Care & Gunsmithing

CNC machining an AR-15 lower

Jason — Thu, 17 Nov 2011 21:06:46 +0000

The following is a post by my friend Jason, who is not a regular contributor, but has posted in the past on our 3D magazine printing project. I thought this would be an interesting addition, and a demonstration of how technology is making gun control a virtual impossibility. Below is his post.

-Sebastian

I’ve been meaning to try this for a while now (using the AR-15 lower receiver solid model from http://www.cncguns.com/downloads.html), but I wanted to do it using all open source software, and was having trouble finding something that could generate tool paths from the AR-15 model. PyCAM seemed to be the best bet, but whenever I tried it on very complex model it would very quickly use up all the memory (8GB of ram plus 8GB of swap) and bring the computer to a screeching halt.

I recently had a project at work where I needed to make a much simpler part, and not wanting to go back to using BobCAD under Windows, I gave HeeksCAD and PyCAM a try. It worked out pretty well, and in the process I discovered and fixed a memory leak in PyCAM

PyCAM is still horribly inefficient in its memory usage, but with the memory leak fixed and a new computer with 16GB of ram I was finally able to generate decent toolpaths for the AR-15 lower.

The equipment/software:

A small Taig desktop CNC mill. http://www.microproto.com/MMDSLS.htm
EMC2 for controlling the mill. http://linuxcnc.org/
HeeksCAD for model manipulation. https://github.com/Heeks
PyCAM for toolpath generation. http://pycam.sourceforge.net/

So now I’m all set to give this a try, but I can’t find the block of aluminum I had intended to use. But I did have a block of Delrin left over from an earlier project, and Delrin should be strong enough to handle a .22 cal upper. So I’m trying to make a delrin lower first for use with a .22 cal upper, and if that works I’ll order some aluminum and make another lower for use with a .223 upper.

Note that I’m not an expert in material properties (nor a machinist) so don’t take the above statements to mean that its safe to fire an AR-15 made of Delrin. Do at your own risk.

The original block of Delrin.

After a first pass rough cut with a 0.25″ diameter end mill.

After a second pass using a 0.125″ end mill and a much smaller grid size.

After a finishing pass with a 0.125″ ball nose mill.

Now things are going to get a little complicated. I’m going to have to make some sort of jig to hold the part in place while I machine the other side.

Nifty AR-15 Cleaning Tool

Sebastian — Wed, 05 Oct 2011 01:21:23 +0000

I am intrigued by this tool originally brought to the community by The Firearm Blog:

I am an anal retentive gun cleaner, when I set out to clean. I get over this obsession by trying not to think about it. But when I tear down a gun for cleaning, I want everything immaculate. This tool would seem to be tailor made for the anal retentive.

I say that because I’ve never been convinced that buildup on that particular part mattered in terms of function and reliability of the system. Certainly the rings need to be clean, but do you care about the part that shown being clean in the video?

Gunsmith of Williamsburg, and Other Junior High Films

Sebastian — Thu, 16 Sep 2010 01:23:22 +0000

Many thanks to Clayton for pointing this series of videos out:

You can see some other parts on YouTube here and here. I probably watched some of the Colonial Williamsburg Foundation videos myself when I was in Junior High too. It’s occurred to me that I was probably among the last of the 16mm film reel generation. When I entered high school, the schools were just starting to get the newfangled Laser Discs, which could be controlled with a nifty Apple IIGS computer. Kids today will never know the disappointment of being subject to regular lessons because the projector wouldn’t track correctly, the film reel broke, or the bulb in the projector blew out (some teachers knew how to fix these things, others didn’t). I’m sure with a new generation of media came a new generation of films, which means kids today will miss out on the delight of what I saw in Volcano National Park in Hawaii, reliving some interests from childhood:

Parts two, three and four if you’re interested. Documentary filmmaking today doesn’t have the same dry, cheesy appeal. No dramatic score, or inappropriately deadpan, unenthusiastic narrator. In part four, at the end, I was particularly struck by the fact that they used, as evidence of mother nature recovering, that they tilled over the soil, and planted some papayas, and they grew, dammit! Today it would be some kumbaya crap about fragile native plants that man as clearly destroying growing in the lava, and starting the cycle anew, rather than man punching mother nature right back in her face and getting some farming action back on.

As it is, I hiked through the area mentioned here, and it’s still pretty desolate.

I guess we didn’t punch mother nature quite hard enough. Not often you get to hike on naturally made, volcanic gravel — a remnant of the lava fountain that spewed here for a while.

Glock Trigger

Sebastian — Mon, 19 Apr 2010 15:37:48 +0000

How to make it not suck. An article in Shooting Illustrated by some guy I know down South somewhere ;)

Cleaning and Lubrication Tips from NSSF

Sebastian — Tue, 06 Apr 2010 19:30:31 +0000

NSSF is producing some interesting videos helping people maintain their firearms. This is one of them:

Click here to view the embedded video.

It’s a great service, I think, because a common mistake gun owners make is over-lubricating their guns. I will admit, when I was a beginner gun owner, I used WD-40 to lubricate a gun, which catches fire once it gets hot enough. One advantage to having a Kalashnikov as your first gun is it’ll take pretty much all the abuse you can throw at it with beginner mistakes.

The Gun Designed by Politicians

Sebastian — Mon, 29 Mar 2010 14:42:51 +0000

Tam is having issues with her Ruger Mk.III 22/45. I shoot the Hunter version of the same pistol when I do metallic silhouette, which is a few times a month. The loaded chamber indicator and magazine safety are problems in this design, if you ask me. I haven’t had Tam’s specific problem, but I’ve had other weird malfs that resolve themselves when you remove and re-seat the mag. The magazine safety is just a bad bad idea, for a lot of reasons, and the loaded chamber indicator (also a bad idea) makes the chamber very difficult to clean. The LCI will get gunked up over time, which always makes me nervous, because the smooth operation of the spring on the Mk.III LCI is critical to prevent a strike on the LCI flag from setting off the round (such as if you drop the gun).

I chose to solve the problem of fussy internals by getting a Volquartsen trigger kit. It doesn’t get rid of the two bad features, but it’s much much better than the factory Ruger trigger, and I’ve yet to have any serious problems with stoppages and the like. It helps make the Mk.III into a pretty nice shooter. They also have a kit for the Mk.II as well. I would highly recommend.

I understand that Ruger wants the Mk.III line to be legal in as many states as possible, but my suggestion for Ruger would be to either go back to the original Mk.II design, or at the least make the LCI and mag safety easy to take out. In computer user interface design, it’s a given that you never want to cripple your advanced users for the sake of novices. That philosophy can be applied to pistols too, I think. You can’t really beat the price point of the Mk.III and Mk.II for what you get, and with the addition of the Volquartsen kit, can be just fine for competition use. It’s a shame that anti-gun politicians have turned this flagship brand in American shooting down such a wrong path.

Don’t Give Bad Advice

Bitter — Wed, 23 Dec 2009 19:28:14 +0000

One of the drawbacks of gun owners being a generally helpful bunch is that some try to offer up advice even when they shouldn’t. Yes, shockingly, some gun owners hold themselves out as experts when they don’t know squat. I know this is news to you, especially those of you who regularly chat others up at the range or those of you have spent more than 5 minutes at a gun club.

Snark aside, there are times when it can do serious financial damage. And it makes it worse when such bad advice is found in an official newsletter of an organization that, unjustly, may be seen as an authoritative source.

Yesterday’s mail included the Pennsylvania Rifle & Pistol Association newsletter, the source of the offending advice. One of their directors wrote an article on guns and insurance based on his experience with a devastating home fire. Filing a claim does not make one an expert in insurance. In fact, in Pennsylvania, I couldn’t even get past “Hello” and “please hold” when I got the receptionist at one insurance agency. She said their rules about even discussing insurance when it comes to quotes and advice are crazy strict, so she was not allowed to do anything more than transfer calls, take messages, and assist with non-insurance business needs since she was not licensed.

What follows is when someone who doesn’t seemingly have a background in insurance starts giving advice. (Reproduced as is, including grammatical errors.)

Last January we had a house fire resulting in 15 guns damaged by fire and smoke. I had very good Homeowners Insurance (Allstate “Deluxe” Policy) , and also the supplemental NRA sponsored (Arms Care) Firearms Insurance against fire and theft loss. I hope what follows may be useful information should any fellow members have the same misfortune.

I contacted NRA and told them I was submitting a claim. Their response was that my Homeowners Policy was the first resort and that my NRA policy was residual or secondary coverage in the event that Allstate failed to cover the loss.

Let’s stop here. I don’t have the insurance offered to NRA members for their guns, but my understanding is that the policy is secondary – that it covers above and beyond what your homeowners insurance covers depending on the policy you have with them. I never bothered getting it because my small collection was always under the amount that my renter’s policy covered. So why he would call the insurance company that NRA works with first is beyond me. (At least I’m hoping he called the actual insurance company and not NRA proper. Lord help him if he got caught in that phone menu.)

Allstate, like most other insurance companies, has limited firearms coverage for theft, but will cover all losses due to fire, flood, etc.

Hold up here! What?

All of my life, I have heard that if you live in a flood zone or want flood damage protection, you had to buy separate flood insurance. Google tells me this. More importantly, Allstate even verifies it with this statement:

A flood can be one of the worst disasters that can devastate your neighborhood. It’s such a big deal that the Federal Government runs a National Flood Insurance Program (NFIP). That’s why Home and Property Insurance typically doesn’t cover flooding. (emphasis added)

Now, this guy’s so-called “‘Deluxe’ Policy” may include flood insurance that was recommended because of his community or because he had a salesman who talked him into it. That does not mean that most policies cover damage to your guns from floods. In fact, it means the exact opposite. Fire, yes, but not floods.

Over the course of the next few months I found that Allstate was much more reasonable to deal with, relative to proof of firearms ownership, valuation, etc. than NRA and it’s Insurance carrier.

I’m guessing this guy has a bone to pick with NRA to have thrown that statement in there. At this point, he has already established that

the supplemental insurance is just that – supplemental to what the home & property insurance does not cover;
the primary insurance provider is going to cover the guns fully so he will not need to tap into the supplemental plan; and
hopefully by now he has figured out to call the insurance company and not general NRA staffers.

So beyond just a shot across the bow at NRA, I can’t really figure out why he would be complaining about an insurance policy that he didn’t need to cash in on. Sebastian said that he thought he had heard that the insurance offered to NRA members was a bit of a pain, but that’s not really relevant for this article since the policy didn’t apply in this case.

After advice about safes and suggesting that members go through ADT for all of their home security monitoring needs, he then jumps into the area that just made me want to cringe – handing out insurance purchase advice.

Last but not least, and information well worth repeating, get out your Home Owners Insurance policy, call your agent, and get the maximum coverage, especially on personal contents, temporary housing, structure coverage, that is allowed. If you add up your total cash outlay for Home Owner Insurance coverage over however many years, you will find that it is a fraction of the cost of just one “catastrophic loss” due to fire, flood, or other natural disasters.

If he hadn’t had the absolutely horribly wrong comment about most home policies covering flood damage, then I would believe that he was an insurance agent deliberately trying to oversell folks for things they don’t need.

Now, I am not an insurance expert, but I have purchased enough to know that most people simply do not need a platinum-coated policy for most things covered. I’m also humble enough to admit that I don’t know enough about insurance to say much more.

I will add that if this has made you think about what your gun coverage really is for different types of losses, call your agent. Or, even better, call around until you find an agent who owns guns. I bought my car insurance from an agent who is not only a gun owner who shoots at our club, but his family is full of competitive shooters who hold state records. I know if I had questions, I could call him up and pick his brain to get an honest assessment.

AR-15 Lower Assembling Advice

Sebastian — Wed, 14 Oct 2009 03:25:00 +0000

It is very important to make sure you have the trigger guard pin extensions on your lower receiver properly support when you drive in the trigger guard pin. Don’t ask me how I learned I did not have it well enough supported.

Reloading Presses

Sebastian — Mon, 05 Oct 2009 18:31:37 +0000

TD has a new Lyman reloading press, and offers a review of the equipment. No doubt people will tell him he’s nuts for not just getting a Dillon. I started off with a Lee kit, which worked decently enough. A reader was kind enough to send a Lee progressive press, which I’ve used to reload .44 Magnum. Lee reloading equipment works, but it definitely has its design flaws, especially their progressive presses which have a bit of a Rube Goldberg feel to them, and tend to have minor hiccups which interfere with the reloading process.

Lately I’m pondering getting a rock tumbler so I can handle very significant amounts of brass, and something that will be a little quieter than a vibratory tumbler. Probably not something I’m going to get until I start getting serious about reloading again. But I have been collecting a lot of used brass. Limiting factor for me has been powder, primer, and time.

That Rust Thing

Sebastian — Sat, 15 Aug 2009 02:25:38 +0000

Cemetery comes across a problem we’ve all dealt with at one time or another. Rust. There’s three ways you can deal with rust. One is to keep a coat of oil on your guns, and make sure you wipe them down before you put them away. The other is to keep moisture away from the gun. There are a few ways to do that.

Even thought I love the fact that, as a cowboy shooter that goes by the name of Cemetery, his pistol case is a little coffin, the first piece of advice is not to keep them in the case unless you’re transporting them. This is a surefire way to promote rust. Cases are magnets for moisture.

The second way to prevent rust is to decrease relative humidity. One way you can do that is to increase the temperature within a confined space, thus reducing the relative humidity. This is how a Golden Rod works within the confines of a safe or gun cabinet. Generally speaking, a Golden Rod is the easiest and most maintenance free way to combat rust.

The third way is to actually remove water from air within a confined, largely airtight space. This is what dessicants do. This is the solution I use, because the safe I got a good deal on didn’t have the electrical hookup, and I didn’t have an outlet near where I wanted to put it. Desiccants are effective, but you have to watch them, and they need to be reactivated. Get one that had an indicator compound in them, usually cobalt chloride, which is deep blue when dry, but turns pink as it becomes saturated with water. You can reactivate desiccants by increasing their temperature to 250 degrees. I do my two canisters in the toaster oven at 325 degrees for a few hours. You typically have to recharge once a month in the winter, and once every two weeks or so in the summer. The great thing about desiccants is that you don’t even really need a safe. Any closed, airtight container with a desiccant thrown in will put a stop to rust.