July 22nd, 2018

How Powder Moisture Content Affects Pressure and Speed

vihtavuori vv moisture content powder propellent
This Technical Report Comes from the Vihtavuori website.

Powder Moisture Content — Did You Know?
Variations in moisture content change the burning rate of a powder and thereby chamber pressures and muzzle velocity. The moisture content of the Vihtavuori N100 and N300 series powders is usually around 1%, while the N500-series’ normal moisture content is 0.6% because of the added nitroglycerine.

So what difference does moisture content make? Here’s an example. In a test, a [Vihtavuori] powder sample was dried by heating it, losing about 0.5 % of its weight. Cartridges were then loaded with the dried powder and fired using a pressure gun. Chamber pressures and muzzle velocities produced by these special cartridges were compared to those produced by cartridges loaded with untreated powder. (The powder charge and bullet were of course the same in both sets of cartridges.)

After Powder Drying:
Pressure Increased 11% from 320 MPa to 355 MPa
Velocity Increased 2.6% from 2526 to 2592 FPS

Comparing results showed chamber pressures increased from 320 MPa to 355 MPa with the dried powder, and the muzzle velocity increased accordingly from 770 m/s to 790 m/s (2526 to 2592 FPS). And note, this is only one example, of one caliber and loading. The difference might be much higher depending on the cartridge and loading combinations.

Recommendation: Store powder below 68°F in 55-65% humidity.

What does this tell us? Well, it seems we need to forget the old saying “Keep your powder dry”! Instead, focus on proper powder storage, at a temperature below 20°C/68°F and humidity between 55 and 65%. Safe reloading everybody!

vihtavuori vv moisture content powder propellent

Tech Tip sourced by EdLongrange. We welcome reader submissions.
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July 22nd, 2018

Rimfire Sporter Match Today at Camp Perry

Rimfire Sporter Match CMP Camp Perry

Today, July 22, 2018, the CMP hosts the popular Rimfire Sporter Match at Camp Perry. A great event for shooters of all ages and skill levels, the Rimfire Sporter Match will attract hundreds of shooters. This year a special smart-phone App will be used to speed up scoring.

GET CMP Rimfire Sporter Guidebook | VIEW AccurateShooter’s Rimfire Sporter Page

rimfire sporter match Camp Perry Ohio
Hundreds of shooters will compete in the Rimfire Sporter Match today at Camp Perry.

Rimfire Sporter Course of Fire

Competitors will complete slow fire prone, rapid fire prone, slow fire sitting or kneeling, rapid fire sitting or kneeling, slow fire standing, and rapid fire standing shot sequences. To learn more about the National Rimfire Sporter Match, CLICK HERE.

National Rimfire Sporter Match Camp Perry 2016

Rimfire Sporter Classes

Three different classifications of rifles can be used in Rimfire Sporter competition: “O Class” for open-sighted rifles, “T Class” for telescope-sighted rifles, and the recently-added “Tactical Rimfire” class. Awards are offered to High Juniors, High Seniors, High Women as well as Overall winners are named for each class.

National Rimfire Sporter Match Camp Perry 2016

National Rimfire Sporter Match Camp Perry 2016

National Rimfire Sporter Match Camp Perry 2016

Do you want to see more match photos? CLICK HERE to view the CMP Zenfolio Archive with 500+ photos from 2016 National Rimfire Sporter Match.

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July 22nd, 2018

Hang Your Handguns to Conserve Safe Space

hand gun storage solution under shelf handgun hanger coated wire

If you’re looking for a space-saving handgun storage system, consider the Easy Use Gun Hangers from USA GunClub. These vinyl-coated, wire hangers organize handguns below the shelves in your gunsafe, freeing up storage space above the shelves. To use the handgun hangers, simply slide each hanger on the shelf and then slip your pistol’s barrel over the lower rod. Handgun Hangers are intended for guns with an overall length of 10 inches or shorter. They will fit shelves that are at least 11 inches deep and 5/8-1 inch in thickness. Handgun Hangers will hold handguns .22 caliber and up, though the fit is a bit snug on .22s. A four-pack of Handgun Hangers costs $8.99. This product is now Amazon’s #1 Best Seller among handgun storage accessories.

hand gun storage solution under shelf handgun hanger coated wire

WARNING — Always Make Sure Handgun is UNLOADED when using Handgun Hangers!!

hand gun storage solution under shelf handgun hanger coated wireUSA GunClub also offers an Over-Under Hanger that holds two handguns — one above the shelf, and one below. A two-pack of Over-Under Hangers (capable of holding four handguns) costs $7.99. This may be a good solution for you. This Editor personally prefers the standard Handgun Hanger, so I can use the upper surface of the shelf to hold odd-shaped items such as cameras, binoculars, and miscellaneous valuables.

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