Posts

Here is a list of some loads I have used for 6x45mm. General observations:

• Projectiles much heavier than 95gr are problematic when it comes to seating with the COAL of 2.250".
• I’ve found that IMR 8208 XBR grouped the best and QuickLoad tells me it burns better for this particular cartridge. However BL-C(2) does seem to be easier for me to find.
• I did have to get a seperate seating die for the longer/heavier projecticles as the original one would leave a ring on the projectile itself.

The dies are from Redding.

The 8mm Mauser (7.92x57mm) round, in it’s current incarnation, has been around since 1903. It is a improvement of the original 7.92x57mm cartridge that was developed in 1888 by Peter Paul Mauser. Arguably, 8mm Mauser has been one of the world’s most popular cartridges, having seen significant military and civilian use over the past 100+ year. It also influenced the design of many of today’s cartridges, such as .30-06.

Finding good 8mm Mauser ammunition (in Canada at least) is becoming harder. The glut of military surplus rifles and ammunition for this cartridge is long over, and there are more modern cartridges which have gained a significant following.

After an amateur attempt at trying to calculate the BC of the Norinco 7.62x39mm ammunition, I thought I would do the same thing with Norinco’s 7.62x51mm ammo. As one would expect, this stuff is fairly inexpensive as well, running around $0.50/round. I don’t think this is “precision ammo”, but it works well enough in my rifle.

First off, I pulled one bullet apart, and weight it. The projecticle itself weight 146.1 grains, so I guess this is supposed to be 147gr ammo. I measured ~ 42.0 grains of “mystery gun powder”.

On of the great things about 7.62x39mm rifles (like the SKS) is that (at the time of writing) ammo is fairly inexpensive. A fellow who keeps his eye open for a deal can find 7.62x39mm in the range of $0.16CAD (for corrosive) to $0.30CAD (for non-corrosive) ammo. Of course being surplus ammo, finding ballistics data on this ammunition can be a bit of a trick. Granted, the 7.62x39 cartridge isn’t exactly a “precision” round, but intellectual curiousity had me wondering what the ballistic coefficient (BC) of this Norinco ammo was.

This weekend I finally broke down and installed a 2nd generation Nest thermostat in my house. They have a nice compatibility wizard which does a pretty good job of showing you how to wire up your Nest based on the wires you can see in your existing thermostat. There were two gotchas that their wiring diagram didn’t cover. Here is a picture of the old thermostat (a Rodgers-White):

Notice that there were two W wires. I’m not to sure what is up with that, I suspect that that one wire leads up to the humidifier. I ended up splicing the two wires together with a marette, and then connecting the spliced wire to the W connection on the Nest. This was not documented anywhere on the Nest website.

The Ping))) is ultrasonic range finder that is pretty easy to use in an Arduino project. In my case, I’m using it to monitor the water level in a sump pump. I have an Arduino Uno R3 (with Ethernet Shield) connected to a Ping))) and a TMP36 temperature sensor that is perched above my sump pump. Every 2 minutes the Uno will send out a ping, and figure out the distance to the water below. The TMP36 is used to account for the air temperature in the speed of sound calculations.

If you’re looking to get into Arduino, and you’re a programmer, the first thing that will jump out at you is the Arduino IDE. It’s best described as “spartan” (to say the least). As I’m used to full featured IDE’s I started looking for a replacement to the default Arduino IDE.

There are extensions to use Visual Studio, but that means me starting up a VM to run Windows which I don’t really want to do for Arduino development. There is a another IDE which looks promising called Maria Mole - but it’s Windows only so not really a contender for me. I need something for OS X. I looked at setting up Eclipse as my default IDE, but ran into some issues with that. Nothing to major, but as I don’t like Eclipse in the first place I wasn’t to motivated to sort things out, so I abandoned Eclipse as an IDE choice.

The next thing I tried was Sublime Text. There is an Ardunio plugin called Stino that turns Sublime into a not bad IDE. In terms of writing your programs, Stino can pretty much do everything the Arduino IDE can do: compile programs, upload them to your Arduino board, import libraries, etc.

One of the handy things about the JPEG format is the ability to store meta-data inside the image using EXIF. There are a few libraries out there for the various programming languages that can help you out with this, and Android actually has something built in to the SDK - the class ExifInterface.

Google’s documentation on writing latitude and longitude to a JPEG are a bit light on details - they loosely hint at the format that latitude or longitude should have. (See the documentation for ExifInterface.TAG_GPS_LATITUDE). The API itself is pretty straight forward, but what Google doesn’t tell you is HOW the GPS coordinates should encoded.

I have a simple little pet project (for Android), and one of the things I wanted to do was to to have a text field that would show me previous values as I typed in the text box (see screenshot below). Of course, this control is already a part of the Android SDK - it’s our good friend the AutoCompleteTextView.

To populate the drop-down, I have an SQLite table called vehicle_descriptions, which looks something like the screenshot below. What I want is for a given vehicle (a value derived from another control on my Activity) to show me the value of the description column in the table.

I ran into a curious problem for a side problem of mine where I had some information in PDF files, both text and images.  What I want to do is display the information from the PDF’s on a mobile (Android) device.  PDF isn’t exactly a mobile friendly format, so I got the idea use HTML.  The next trick then becomes how to get the content out of the PDF’s I want into HTML.  Tux to the rescue!