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The Optical Open Sight.

Free Stuff August 20, 2017

The Optical Open Sight (OOS)
by John Andrew

 Of all the non-magnifying optical sighting systems the OOS could be both the simplest and the least known. A commercial version is presently produced and sold in the US. Named the SeeAll, most Australian shooters are not yet aware of it (as of late 2016) but could find a visit to the web site interesting.

The OOS is so simple that it’s practical to home build basic versions of it, and that’s been the go in my man cave for a while now. The following describes my efforts in putting the OOS idea to work for various forms of short range shooting as an alternative to a red-dot sight.

Popular red-dot sighting systems are usually an improvement on basic open sights but they sacrifice attributes that could be sadly missed. These could include, low cost, light weight, compactness, and suitability for use

1899 total views, 1 today

Free Screensaver Early Machine Guns

Free Stuff July 4, 2011


Maxim, Gatling, Spandua, Vickers, Lewis, Mg 34, Bren,

Just click and watch or Hit full screen button

2308 total views, 4 today

Reloaders Guide – Alliant Powder

Free Stuff April 11, 2011

Alliant Powder Reloaders Guide 2011

The Reloaders Guide can be downloaded free of charge by right clicking the following link and selecting “Save Target as” to save to your PC:

Reloaders Guide 2011 – Alliant Powder

NOTE: left clicking the link will open the 10MB PDF file in your browser if you have Adobe Reader installed.  This is a big file and opening in your browser is not recommended unless you have a broadband connection

The download file is AlliantPowderCatalog.pdf (10 MB PDF file).  You will need a PDF reader program to open and view the document.  Adobe Reader can be downloaded free from www.adobe.com


Ron Owen
Owen Guns, Gympie Australia.…

2651 total views, 1 today

External Ballistics Calculator

Free Stuff May 24, 2009

A Ballistic Spreadsheet

Using  BallisticSS –  a ballistic spreadsheet           (notes by J. S. Andrew  Dec. 2009)

This public domain (free) spreadsheet file is made available for download by Owen Guns. The Ballistics Calculator will give a lot of answers to questions by shooters who have a computer with either Excel or OpenOffice.org installed. To obtain a copy of the FREE Ballistics Calculator, please send an email to owenguns@spiderweb.com.au with the subject line “Ballistics Calculator”.


By entering values for any practical combination of MV (or velocity at a nominated range), Ballistic Coefficient, Bullet Weight, Sight Height (scope axis above bore axis), a desired Zero Range, and the actual target ranges you are interested in, the spreadsheet will instantaneously display ballistic predictions at those ranges. Remaining velocity and kinetic energy, drop from line of departure, bullet path above or below line of sight, and the bullets time of flight are given …

2837 total views, 2 today

Free Ballistics Calculator

Free Stuff January 9, 2009

The Free Ballistics Calculator can be downloaded free of charge by clicking the following link:

Free Ballistics Calculator

The download file is BallisticSS-20091207.zip, a ZIP archive file containing  the actual calculator file which is BallisticSS 20091207.xls.

Clicking the link will open a download window – click the Save button to save the file to your PC.  Once downloaded, double click the file to extract the BallisticSS 20091207.xls file to your PC (you may need to download the free 7-ZIP program if you have trouble extracting the Excel file – it can be downloaded from www.7-zip.org.

Please read the information page at http://www.owenguns.com/external-ballistics-calculator/ for details on using the calculator.


Ron Owen
Owen Guns


2284 total views, 2 today


Free Stuff September 22, 2008


From the time a firearm is grasped in the hand, the shooter becomes a part of a system over which the shooter has complete control. The shooter is the only part of the system that can make a gun safe – or unsafe.

Hunting and target shooting are among the safest of all sports. This study is intended to make them even safer by re-emphasizing and reaffirming the basics of safe gun handling and storage and by reminding each individual shooter that he or she is the key to firearms safety.

You can help meet this responsibility by constantly stressing safety when handling firearms, especially to children and non-shooters. Newcomers in particular must be closely supervised when handling firearms with which they may not be acquainted. Don’t be timid when it comes to gun safety. It you observe anyone violating any safety precautions, you have an obligation to suggest …

2057 total views, 2 today

Keyhole Shots

Free Stuff September 21, 2008

Keyhole Shots

An injury to the muzzle of a rifle can cause shots to keyhole. This condition is most likely to occur in rifles cleaned from the muzzle, but may be due to accident, such as striking the muzzle against any metal.
A very small burr on the muzzle crown can make the bullets unstable in flight.

Anything that reduces the rotations per second may cause a bullet to tip. Low bullet velocity may reduce the spin enough to cause this effect. A long bullet requires more spin than a short one, so that too long a bullet for the twist or too slow a twist for the bullet may cause tipping. Excessive wear of the rifling or too loose a fit of the bullet in the barrel may cause the bullet to fail to take the full spin required.
As barrel erosion progresses, the portion of the barrel just …

4275 total views, 2 today

A Loaded Muzzle Loader

Free Stuff September 21, 2008

A Loaded Muzzle Loader

“I didn’t know it was loaded”

“I didn’t know it was loaded” is the stock expression used by those who are rudely awakened by an explosion when they pull the trigger of a any loaded firearm. Muzzle loading firearms seem to be even more prevalent in this due to the lack of observation of the chamber. They seem to be always presumed empty.

An old muzzle loader is more likely to be loaded than would at first be thought. One reason lies in its slowness of loading. This resulted in many muzzle loaders being kept loaded habitually, as the only way of keeping them ready for use. Another reason lies in the difficulty of unloading, which caused many users to put off that tedious operation and finally forget it.
It was usual to leave the cap (or priming charge, depending on the type of ignition) off …

2209 total views, 3 today

Ammunition is Effected by Temperature

Free Stuff September 14, 2008

Ammunition is Effected by Temperature

Temperature has a marked effect on both velocity and pressure. Factory ammunition is, as a rule, rather conservatively loaded so that no danger will result even under extremes of temperature.
Twenty years ago a large quantity of 6.5 x 55 ammunition was imported into Australia, (I was responsible for a few million round of it) It was 139 grain FMJ brass case with a berdan primer I suspect made by Norma in Sweden. In normal conditions it was excellent ammunition. (I once shot a five shot.500 inch group at 200m with it). There were reports that it had blown up guns, on investigation this was not the same ammunition only the same calibre. It got everybody talking though.

A southern importer had imported blank ammunition in this calibre and had replaced the wooden blank projectiles with 140 grain soft points. This would not have been …

2189 total views, 1 today

Exploding Barrel Blockages

Free Stuff September 12, 2008

Exploding Barrel Blockages

Bore Blockages

Obstructions in a firearm barrel are almost certain to damage the barrel on firing.
The kind and amount of damage depend on location of the obstruction, on its mass (weight), and on the type and thickness of the barrel. A very great variety of results are possible. I have known of them killing the shooter next on the firing line, and only giving the owner of the firearm a sore shoulder. This is the extreme but it can and does happen.

An obstruction close in front of the cartridge in the chamber has the effect of increasing the chamber pressure. An obstruction in the middle or forward part of the barrel produces a local injury.
The action of an obstruction does not depend on trapping air. Experiments with coils of wire and other open obstructions resulted in damage about the same as solid obstructions of …

3204 total views, 2 today


Free Stuff May 23, 2008



Action: Breech mechanism of a firearm, by which it is loaded and unloaded, and which houses most of the moving parts.

Airgun: Not a firearm but a gun that uses compressed air or CO2 to propel a projectile. Examples: BB gun, pellet gun, CO2 gun.

Ammunition: This generally refers to the assembled components of complete cartridges or rounds i.e., a case or shell holding a primer, a charge of propellant (gunpowder) and a projectile (bullets in the case of handguns and rifles, multiple pellets or single slugs in shotguns). Sometimes called “fixed ammunition” to differentiate from components inserted separately in muzzle loaders.

Antique: By federal definition, a firearm manufactured prior to 1899 or a firearm for which ammunition is not generally available or a firearm incapable of firing fixed ammunition.

Anvil: In a primer or cartridge case a fixed point which the priming mixture is crushed, …

1974 total views, 2 today

Glossary For Optics

Free Stuff May 22, 2008

Optical Glossary

A lens classed as achromatic has been formulated to be free of chromatic aberration, which causes colour fringing. An achromatic lens, or achromat, achieves identical focus with light rays of two different colours.

Apochromatic lenses are corrected to bring all three primary colours to the same focus.

Aberration in a lens or optical system that makes lines oriented in certain directions less sharply focussed than lines running in other directions. Astigmatism also occurs in the human eye. A typical astigmatic effect would be to see the vertical lines on a sheet of graph paper sharply while seeing the horizontal lines less clearly, or vice versa.

In scope sights with ends flared to accommodate large-diameter ocular or objective lenses, the oversized lens housings are referred to as bells, as in ocular bell or objective bell.

Binocular Collimation
Regulating the two halves of a binocular for …

1736 total views, 2 today

Explosives Glossary

Free Stuff May 21, 2008


Alarm: a signal given by an EDS that indicates to the operator that a detection of explosive material has been made. For a technological system such as an IMS the alarm might be either audio (e.g., a buzzer sounds) or visual (e.g., a message on a computer screen). In the case of a canine, the alarm is some form of behaviour by the dog which the handler interprets as a detection.

Alarm resolution: the process by which an operator determines whether an alarm is the result of a threat item being present, or whether in fact there is no threat item present.

Alarm threshold setting: the signal level above which an EDS is set to alarm. An EDS may make a detection of an amount of explosive below the alarm threshold setting, but it will then be assumed that the signal obtained is either (1) …

2606 total views, 1 today

Range Glossary

Free Stuff May 21, 2008


Back Stop 
Sometimes called Butts or Butt stop, generally a raised area that prevents bullets or projectiles leaving the range.

Backing Cards 
Card behind scoring targets to either increased vision of the bullet hole or confirm amount of shots in one hole.

Bench Rest 
Heavy table equipped with a Rifle Rest and Sand Bags for Bench Rest competition or sighting in firearm to zero.

Bullet Blocks 
Wooden blocks used to stand ammunition in.

Bullet Catcher or Collector Systems
Situated at the stop butts that prevent ricocheting bullets or projectiles from leaving the range area.

Area behind a raised mound with an underground trench to allow.

Butt Markers
People who score and change the targets for shooting competitors.


Cease Fire!
Range Officers Order to Stop shooting.

Ear Protection 
Ear Muffs or plugs, both have as high safety rating,. (red box or packet) Many shooters using low …

1670 total views, 2 today