July 1st, 2017

Smarter Shooter: Keep Your Ammo Cool on Hot Summer Days

Heat Map USA color chart

Well folks, it’s July 1st already — the means we’re moving into “peak heat” summer conditions. It’s vitally important to keep your ammo at “normal” temps during the hot summer months. Even if you use “temp-insensitive” powders, studies suggest that pressures can still rise dramatically when the entire cartridge gets hot, possibly because of primer heating. It’s smart to keep your loaded ammo in an insulated storage unit, possibly with a Blue Ice Cool Pak if you expect it to get quite hot. Don’t leave your ammo in the car or truck — temps can exceed 140° in a vehicle parked in the sun.

Ammo cool storage

Bosch Insulated tool caseTo learn more about how ambient temperature (and primer choice) affect pressures (and hence velocities) you should read the article Pressure Factors: How Temperature, Powder, and Primer Affect Pressure by Denton Bramwell. In that article, the author uses a pressure trace instrument to analyze how temperature affects ammo performance. Bramwell’s tests yielded some fascinating results.

For example, barrel temperature was a key factor: “Both barrel temperature and powder temperature are important variables, and they are not the same variable. If you fail to take barrel temperature into account while doing pressure testing, your test results will be very significantly affected. The effect of barrel temperature is around 204 PSI per F° for the Varget load. If you’re not controlling barrel temperature, you about as well might not bother controlling powder temperature, either. In the cases investigated, barrel temperature is a much stronger variable than powder temperature.”

Powder Heat Sensitivity Comparison Test

Cal Zant of the Precision Rifle Blog has published a fascinating temp-stability comparison test of four powders: Hodgdon H4350, Hodgdon Varget, IMR 4451, and IMR 4166. The first two are Hodgdon Extreme powders, while the latter two are part of IMR’s new Enduron line of propellants.

CLICK HERE to VIEW FULL TEST RESULTS

The testers measured the velocity of the powders over a wide temperature range, from 25° F to 140° F. Hodgdon H4350 proved to be the most temp stable of the four powders tested.

Precision Rifle Blog Temperature Stability test hodgdon varget H4350 Enduron IMR 4451

Permalink Bullets, Brass, Ammo, Reloading, Tech Tip No Comments »
June 9th, 2017

Humidity and Powder Burn Rates — What You Need to Know

Tech Tip Norma Powder gunpowder moisture temperature humidity

Most shooters realize that significant changes in temperature will alter how powders perform. That’s why you want to keep your loaded ammo out of the hot sun, and keep rounds out of a hot chamber until you’re ready to fire. But there are other factors to be considered — HUMIDITY for one. This article explains why and how humidity can affect powder burn rates and performance.

We’ve all heard the old adage: “Keep your powder dry”. Well, tests by Norma have demonstrated that even normal environmental differences in humidity can affect the way powders burn, at least over the long term. In the Norma Reloading Manual, Sven-Eric Johansson, head of ballistics at Nexplo/Bofors, presents a very important discussion of water vapor absorption by powder. Johansson demonstrates that the same powder will burn at different rates depending on water content.

Powders Leave the Factory with 0.5 to 1.0% Water Content
Johansson explains that, as manufactured, most powders contain 0.5 to 1% of water by weight. (The relative humidity is “equilibrated” at 40-50% during the manufacturing process to maintain this 0.5-1% moisture content). Importantly, Johansson notes that powder exposed to moist air for a long time will absorb water, causing it to burn at a slower rate. On the other hand, long-term storage in a very dry environment reduces powder moisture content, so the powder burns at a faster rate. In addition, Johansson found that single-base powders are MORE sensitive to relative humidity than are double-base powders (which contain nitroglycerine).

Tests Show Burn Rates Vary with Water Content
In his review of the Norma Manual, Fred Barker notes: “Johansson gives twelve (eye-opening) plots of the velocities and pressures obtained on firing several popular cartridges with dehydrated, normal and hydrated Norma powders (from #200 to MRP). He also gives results on loaded .30-06 and .38 Special cartridges stored for 663 to 683 days in relative humidities of 20% and 86%. So Johansson’s advice is to keep powders tightly capped in their factory containers, and to minimize their exposure to dry or humid air.”

Confirming Johansson’s findings that storage conditions can alter burn rates, Barker observes: “I have about 10 pounds of WWII 4831 powder that has been stored in dry (about 20% RH) Colorado air for more than 60 years. It now burns about like IMR 3031.”

What does this teach us? First, all powders start out with a small, but chemically important, amount of water content. Second, a powder’s water content can change over time, depending on where and how the powder is stored. Third, the water content of your powder DOES make a difference in how it burns, particularly for single-base powders. For example, over a period of time, a powder used (and then recapped) in the hot, dry Southwest will probably behave differently than the same powder used in the humid Southeast.

Reloaders are advised to keep these things in mind. If you want to maintain your powders’ “as manufactured” burn rate, it is wise to head Johannson’s recommendation to keep your powders tightly capped when you’re not actually dispensing charges and avoid exposing your powder to very dry or very humid conditions. The Norma Reloading Manual is available from Amazon.com.

Real-World Example — “Dry” H4831sc Runs Hotter

Robert Whitley agrees that the burn rate of the powder varies with the humidity it absorbs. Robert writes: “I had an 8-lb. jug of H4831SC I kept in my detached garage (it can be humid there). 43.5-44.0 gr of this was superbly accurate with the 115 Bergers out of my 6mm Super X. I got tired of bringing it in and out of the garage to my house for reloading so I brought and kept the jug in my reloading room (a dehumidified room in my house) and after a few weeks I loaded up 43.5 gr, went to a match and it shot awful. I could not figure out what was going on until I put that load back over the chronograph and figured out it was going a good bit faster than before and the load was out of the “sweet spot” (42.5 – 43.0 gr was the max I could load and keep it accurate when it was stored in less humid air). I put the jug back in the garage for a few weeks and I now am back to loading 43.5 – 44.0 gr and it shoots great again. I have seen this with other powders too.”

If you have two jugs of the same powder, one kept in a room in your house and one somewhere else where it is drier or more humid, don’t expect the two jugs of the same lot of powder to chrono the same with the same charge weights unless and until they are both stored long enough in the same place to equalize again.

Permalink - Articles, Reloading 4 Comments »
May 23rd, 2017

Tuning Tips — Pressure, Powder Fouling, and Temperature

Pressure Temperature Fouling Tech Tips Tommy Todd Sierra Bullets

by Tommy Todd, Sierra Bullets Chief Ballistician for Sierra Bullets Blog
I have shot several disciplines of shooting competitions over the years and have learned a few things regarding ammunition and bullet function during this time. Frequently the matches I shoot require 40 to 100 shots before a person gets a chance to clean his rifle. Just as frequently, a good shooting match rifle will still shoot very good scores and groups with that many rounds fired through them. However, those guns do not deliver the same accuracy as when they were clean, but the drop-off in accuracy is not a huge change unless a set of accumulative issues arise.

In one situation, very dirty powder created more serious problems…

Pressure Issues — Extraction Problems Caused by Bad Fouling

Problem: Pressures Increased as Powder Fouled Barrel and Carbon Ring Formed
Solution: Clean Barrel Every Ten Rounds.

I witnessed a set of problems that occurred with a fellow competitor’s rifle at a recent F-Class match. He was using a large case capacity cartridge for the bore diameter and he was shooting a powder that was burning extremely dirty. As the match progressed, the carbon buildup caused most likely a carbon ring in the throat of the rifle and pressures kept increasing to the point that the cases were hard to extract, bolt lift was excessive, and eventually he quit shooting the rifle due to these issues. Accuracy also suffered as could be evidenced by the gun’s performance on target. This load looked fine when he was developing it, none of the excessive pressure signs appeared when he worked the load up, but he was cleaning the gun every ten shots.

When he was shooting multiple, 20-shot strings during the match is when the issues appeared. He was able to give the gun a thorough cleaning and the issues went away, for several rounds and then the pressures started appearing again. These pressure signs were not due to ambient temperatures as it was a cool spring morning and the temperature was in the low 40° range.

Accuracy Issues — Tune Lost with Higher Ambient Temps

Problem: Accuracy Lost When Outside Temp Much Hotter than When Load Developed
Solution: Pull Bullets, Reload Ammo with Lighter Charge

A couple of years ago, I attended a match early in the shooting season and it was unusually hot for that time period. I heard a competitor worrying before the match about his gun “blowing up”. At first I was concerned, but after thinking about what he had said I realized that he meant his “accuracy” blowing up, meaning he knowingly had loaded his ammunition at the top end of an accuracy tune that he established via a ladder test. The next day I asked him how his scores were and he said the gun was not shooting very well initially, but he had found enough equipment from friends that were at the match and had pulled the bullets, reduced the powder charge by a few tenths of a grain and re-seated the bullets and his gun was now shooting normally. The temperature difference between his home range the weekend before when he established his load and the match conditions was about 30 degrees and that was enough to cause an accuracy change at 1000 yards.

Ammo cool storage

Bosch Insulated tool caseTo learn more about how ambient temperature (and primer choice) affect pressures (and hence velocities) you should read the article Pressure Factors: How Temperature, Powder, and Primer Affect Pressure by Denton Bramwell. In that article, the author uses a pressure trace instrument to analyze how temperature affects ammo performance. Bramwell’s tests yielded some fascinating results.

For example, barrel temperature was a key factor: “Both barrel temperature and powder temperature are important variables, and they are not the same variable. If you fail to take barrel temperature into account while doing pressure testing, your test results will be very significantly affected. The effect of barrel temperature is around 204 PSI per F° for the Varget load. If you’re not controlling barrel temperature, you about as well might not bother controlling powder temperature, either. In the cases investigated, barrel temperature is a much stronger variable than powder temperature.”

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August 24th, 2016

Sierra Test Reveals How Velocity Varies with Ammo Temperature

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold
In this .308 Win test, 70° F ammo shot 96 FPS slower than ammo heated to 130.5° F. And the 130.5° ammo was 145 fps faster than ammo right out of the freezer (at 25.5° F). That’s a huge difference…

EDITOR’s NOTE: The Sierra tester does not reveal the brand of powder tested here. Some powders are much more temp sensitive than others. Accordingly, you cannot extrapolate test results from one propellant to another. Nonetheless, it is interesting to see the actual recorded velocity shift with ammo temperature variations in a .308 Win.

Written by Sierra Chief Ballistician Tommy Todd
This story originally appeared in the Sierra Bullets Blog
A few weeks ago I was attending the Missouri State F-Class Match. This was a two-day event during the summer and temperatures were hot one day and hotter the next. I shot next to a gentleman who was relatively new to the sport. He was shooting a basically factory rifle and was enjoying himself with the exception that his scores were not as good as he hoped they would be and he was experiencing pressure issues with his ammunition. I noticed that he was having to force the bolt open on a couple of rounds. During a break, I visited with him and offered a couple of suggestions which helped his situation somewhat and he was able to finish the match without major issues.

He was shooting factory ammunition, which is normally loaded to upper levels of allowable pressures. While this ammunition showed no problems during “normal” testing, it was definitely showing issues during a 20-round string of fire in the temperatures we were competing in. My first suggestion was that he keep his ammunition out of the direct sun and shade it as much as possible. My second suggestion was to not close the bolt on a cartridge until he was ready to fire. He had his ammo in the direct sunlight and was chambering a round while waiting on the target to be pulled and scored which can take from a few seconds to almost a minute sometimes.

This time frame allowed the bullet and powder to absorb chamber [heat] and build pressure/velocity above normal conditions. Making my recommended changes lowered the pressures enough for the rifle and cartridge to function normally.

Testing Effects of Ammunition Temperature on Velocity and POI
After thinking about this situation, I decided to perform a test in the Sierra Bullets underground range to see what temperature changes will do to a rifle/cartridge combination. I acquired thirty consecutive .30 caliber 175 grain MatchKing bullets #2275 right off one of our bullet assembly presses and loaded them into .308 Winchester ammunition. I utilized an unnamed powder manufacturer’s product that is appropriate for the .308 Winchester cartridge. This load is not at the maximum for this cartridge, but it gives consistent velocities and accuracy for testing.

I took ten of the cartridges and placed them in a freezer to condition.

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

I set ten of them on my loading bench, and since it was cool and cloudy the day I performed this test I utilized a floodlight and stand to simulate ammunition being heated in the sun.

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

I kept track of the temperatures of the three ammunition samples with a non-contact laser thermometer.

The rifle was fired at room temperature (70 degrees) with all three sets of ammunition. I fired this test at 200 yards out of a return-to-battery machine rest. The aiming point was a leveled line drawn on a sheet of paper. I fired one group with the scope aimed at the line and then moved the aiming point across the paper from left to right for the subsequent groups.

NOTE that the velocity increased as the temperature of the ammunition did.

The ammunition from the freezer shot at 2451 fps.

Frozen FPS

The room temperature ammunition shot at 2500 fps.

Room Temperature FPS

The heated ammunition shot at 2596 fps.

Sierra Bullets Ammunition Ammo temperature temp test hot cold

The tune window of the particular rifle is fairly wide as is shown by the accuracy of the three pressure/velocity levels and good accuracy was achieved across the board. However, notice the point of impact shift with the third group? There is enough shift at 200 yards to cause a miss if you were shooting a target or animal at longer ranges. While the pressure and velocities changed this load was far enough from maximum that perceived over pressure issues such as flattened primer, ejector marks on the case head, or sticky extraction did not appear. If you load to maximum and then subject your ammunition to this test your results will probably be magnified in comparison.

Sierra Bullets Ammunition Ammo temperature temp test hot cold

This test showed that pressures, velocities, and point-of-impact can be affected by temperatures of your ammunition at the time of firing. It’s really not a bad idea to test in the conditions that you plan on utilizing the ammo/firearm in if at all possible. It wouldn’t be a bad idea to also test to see what condition changes do to your particular gun and ammunition combination so that you can make allowances as needed. Any personal testing along these lines should be done with caution as some powder and cartridge combination could become unsafe with relatively small changes in conditions.

Permalink - Articles, Bullets, Brass, Ammo, Reloading 5 Comments »
July 1st, 2016

Beat the Heat: Keep Your Ammo Cool in Summer

Heat Map USA color chart

Well folks, it’s July 1st already — the means we’re moving into “peak heat” summer conditions. It’s vitally important to keep your ammo at “normal” temps during the hot summer months. Even if you use “temp-insensitive” powders, studies suggest that pressures can still rise dramatically when the entire cartridge gets hot, possibly because of primer heating. It’s smart to keep your loaded ammo in an insulated storage unit, possibly with a Blue Ice Cool Pak if you expect it to get quite hot. Don’t leave your ammo in the car or truck — temps can exceed 140° in a vehicle parked in the sun.

Ammo cool storage

Bosch Insulated tool caseTo learn more about how ambient temperature (and primer choice) affect pressures (and hence velocities) you should read the article Pressure Factors: How Temperature, Powder, and Primer Affect Pressure by Denton Bramwell. In that article, the author uses a pressure trace instrument to analyze how temperature affects ammo performance. Bramwell’s tests yielded some fascinating results.

For example, barrel temperature was a key factor: “Both barrel temperature and powder temperature are important variables, and they are not the same variable. If you fail to take barrel temperature into account while doing pressure testing, your test results will be very significantly affected. The effect of barrel temperature is around 204 PSI per F° for the Varget load. If you’re not controlling barrel temperature, you about as well might not bother controlling powder temperature, either. In the cases investigated, barrel temperature is a much stronger variable than powder temperature.”

Powder Heat Sensitivity Comparison Test

Our friend Cal Zant of the Precision Rifle Blog recently published a fascinating comparison test of four powders: Hodgdon H4350, Hodgdon Varget, IMR 4451, and IMR 4166. The first two are Hodgdon Extreme powders, while the latter two are part of IMR’s new Enduron line of propellants.

CLICK HERE to VIEW FULL TEST RESULTS

The testers measured the velocity of the powders over a wide temperature range, from 25° F to 140° F. Hodgdon H4350 proved to be the most temp stable of the four powders tested.

Precision Rifle Blog Temperature Stability test hodgdon varget H4350 Enduron IMR 4451

Permalink Competition, Tech Tip 1 Comment »
December 2nd, 2015

Affordable Weather Meter Works with Mobile Devices

Weatherflow weather meter bluetooth kestrel wind speed air pressure temperature

That smart phone in your pocket is really a miniature computer. What if you could harness that electronic brain to work as a weather meter? You’d just need a way to feed the smart phone environmental data — temperature, humidity, air pressure, wind velocity and so on. Well now that’s possible with the new $69.00 Weatherflow Smart Phone Weather Meter.

This portable, multi-function Weather Meter provides key weather data to your iOS and Android Mobile devices wirelessly via BlueTooth. The unit measures temperature, humidity, air pressure and dew points. With its built-in impeller, the Weather Meter will also record wind speed (average and gust), and wind direction. You can hand-hold it or attach it to a pole/tripod with a standard camera mount. This wireless Weather Meter is compatible with iPhone, iPad, iPod Touch and all major Android devices. The best thing is the price — right now the unit is just $69.00 at Amazon.com.

Reviews by Weather Meter Purchasers

By Wiley on October 2, 2015 — Verified Purchase
I own and love the original WeatherFlow Wind Meter but when I saw this new one that includes temperature, humidity and pressure for under $100, I had to have it. My new weather meter arrived two days after I ordered it and I am amazed at how good this thing is. Solid and well-built, it’s super comfortable in your hand. The hard carry case is nice. The App is pretty simple – start the App and push the button to connect. The meter connected without issue to my iPad mini and my Galaxy S5 (Android) phone. It displays the extra sensor information elegantly, and the data agrees very well with the Davis weather station on my neighbor’s house. Saving and sharing reports is simple. Something cool that’s not obvious until you play with the App a bit are the ‘more data’ you can see (wind chill, heat index, crosswind, headwind, and many others including some I didn’t know existed). I’ve used various Kestrel meters over years and while they are good sensors, Kestrel’s higher price and lack of smart phone integration (or any easy way to get data off the thing) have been frustrating. [Editor: Kestrel’s brand new 5000 Series Weather Meters do offer Bluetooth connectivity as an optional extra.]

Weatherflow weather meter bluetooth kestrel wind speed air pressure temperature

By Richard W. on October 27, 2015 — Verified Purchaser
Great device for the price. It would be nice to interface it with ballistics Apps… but it provides relatively accurate readings and is very small. Finding wind direction is a bit manual (you have to face the device into the wind), but how hard is that? The Bluetooth connectivity is great, you don’t actually have to have it physically connected to the phone — you can put it where you need it.

Technical Details — Compatibility and Settings
The WeatherFlow Weather Meter processes data via a free downloadable App for iOS or Android. The unit works with Apple iPhones 4S or newer, Apple iPads Gen 3 or newer, iPod Touch, and “all major Android devices”. Wireless functionality requires support for Bluetooth version 4.0. You can select either English or Metric units via the “settings” menu. Wind speed units/range are 0.5 to 140 mph; 0.4 to 122 Knots; 0.8 to 225 kph; 0.2 to 63 m/s. Pressure units/range are: 8.9 to 32.5 inHg; 300 to 1100 mbar.

Product Tip from Boyd Allen. We welcome reader submissions.
Permalink New Product, Tech Tip 3 Comments »
June 14th, 2014

Wireless Sensor Measures Temp and Humidity Inside Gun Safe

Golden rod hygrometer wireless sensorHere’s a smart new product that monitors the temperature and humidity inside your gun safe — with a convenient LCD display unit located on the outside of the safe. You don’t need to string wires or cut a small hole in your safe — there are two separate components, one inside and one outside. The sensor unit (on the inside) communicates wirelessly with the display unit (on the outside).

The new GoldenRod Wireless Hygrometer was designed to display the temp/humidity in your safe without the need to open the safe. NOTE: the wireless LCD display can show BOTH in-vault AND in-room humidity and temperature levels. You can attach the display to the vault door with its built-in magnet, or simply place the display unit on top of the safe using the handy flip-out kickstand. The unit costs just $20.89 at Amazon.com.

Golden rod hygrometer wireless sensor

Golden rod hygrometer wireless sensor
Golden rod hygrometer wireless sensor

GoldenRod Wireless Hygrometer Specifications and Features:

  • Measures In-Vault and In-Room humidity from 20% to 95%.
  • Measures In-Vault temperature range from 14°F to 122°F.
  • Measures In-Room temperature range from -4°F to 158°F.
  • Records Min/Max temperature and humidity history.
Product Tip from EdLongrange. We welcome reader submissions.
Permalink Gear Review, New Product 1 Comment »
November 16th, 2012

New Hot Tub™ Ultra-Sonic Cleaning Machine from Hornady

Hornady has announced new products for 2013. These include a number of new bullets, along with new loaded rifle, pistol, and shotgun ammunition. Perhaps most interesting for precision reloaders is Hornady’s new jumbo Ultrasonic Cleaning machine (MSRP $658.33). Featuring a 9-liter capacity, the new Hornady Hot Tub™ is long enough to accommodate and clean a 16-inch AR-15 upper. Along with its large capacity, the Hot Tub has many advanced features.

Hornady Hot Tub Cleaner

New Large-Size Ultra-Sonic Cleaning Machine — the Hot Tub™
For 2013, Hornady will be offering a new, jumbo-sized ultra-sonic cleaning machine that can handle big parts and accessories. In addition to having four (4) transducers, there is also a heating element that enhances cleaning action. Hornady says that “the microjet action of the Hornady® Hot Tub™ removes carbon residue and other debris from cartridge cases, gun parts and other metal equipment.” We know that ultra-sonic cleaning works well on cartridge cases, provided you have a good machine, a suitable solution, and run the machine for an appropriate time.

Hornady Hot Tub Cleaner

The new Hot Tub is well-equipped out of the box. One 1.7 quart inner tank comes with the unit and can be used in the main tank for cleaning multiple smaller batches or to use separate solutions at the same time. Additional inner tanks can be purchased separately. Hanging cords have been integrated into the design to allow large objects to take full advantage of the ultrasonic energy. Additionally, the Hot Tub® features integrated drain pans in the lids, a small parts basket, a degas function and five (5) temperature settings from 100-140°F.

Hornady Hot Tub Cleaner

Watch Video to See Hornady Hot Tub Ultra-Sonic Cleaning Machine in Action

Hornady Hot Tub Cleaner

Permalink - Videos, New Product 2 Comments »
June 10th, 2012

Keep Your Ammo Cool in Insulated Multi-Purpose Carry Pack

It’s vitally important to keep your ammo at “normal” temps during the hot summer months. Even if you use “temp-insensitive” powders, studies suggest that pressures can still rise dramatically when the entire cartridge gets hot, possibly because of primer heating. It’s smart to keep your loaded ammo in an insulated storage unit, possibly with a Blue Ice Cool Pak if you expect it to get quite hot. Don’t leave your ammo in the car or truck — temps can exceed 140° in a vehicle parked in the sun.

NorChill Cooler bagInsulated Case Does Double-Duty
Standard plastic coolers work fine, but if you don’t want to borrow the family’s food carriers, consider this Norchill insulated Cooler Bag. When not used to keep your ammo cool, the 7″ wide x 12″ high x 14″ long small Norchill Bag doubles as a gear carrier. Norchill bags feature dual-temp insulation and a waterproof inner liner. With side-zip compartments, Norchill Cooler Bags are more versatile than typical plastic coolers. These Norchill cooler bags are soft, collapsible and can be rolled up to fit into your carry on luggage. When not in use for ammo, they can be used to as a suitcase, or carry bag for cameras, optics, and electronic gear.

Norchill Bags come in three sizes and a variety of colors. Price starts at $39.99 for the small bag (12-can capacity) is $39.99. The 10″x12″x18″ medium bag has double the capacity (24 cans) and costs $49.99. There is also a jumbo 48-can capacity bag, 13″x13″x21″. But this is probably more capacity than you’d ever need.

Ammo cool storage

Bosch Insulated tool caseTo learn more about how ambient temperature (and primer choice) affect pressures (and hence velocities) you should read the article Pressure Factors: How Temperature, Powder, and Primer Affect Pressure by Denton Bramwell. In that article, the author uses a pressure trace instrument to analyze how temperature affects ammo performance. Bramwell’s tests yielded some fascinating results.

For example, barrel temperature was a key factor: “Both barrel temperature and powder temperature are important variables, and they are not the same variable. If you fail to take barrel temperature into account while doing pressure testing, your test results will be very significantly affected. The effect of barrel temperature is around 204 PSI per F° for the Varget load. If you’re not controlling barrel temperature, you about as well might not bother controlling powder temperature, either. In the cases investigated, barrel temperature is a much stronger variable than powder temperature.”

Permalink Bullets, Brass, Ammo, Gear Review 2 Comments »
March 1st, 2011

New AR-Comp Powder from Alliant — Details Revealed

AR-Comp Alliant PowderHere’s the latest info on Alliant’s new AR-Comp powder. We had a chance to talk with Dick Quesenberry of Alliant, who revealed more details about this new propellant. First, Dick explained that AR-Comp is an advanced re-formulation of Reloder 15, a double-base Bofors powder. There are changes to internal and external chemistry to provide much better pressure/velocity stability across a wide range of temperatures.

AR-Comp Offers Uniform Velocities over a Wide Temp Range
Tests were done with .223 Rem and .308 Win ammo, loaded with AR-Comp and maintained at temps from -20° F to +160° F in a controlled test center. The ammo itself was heated or cooled to targeted temps before testing. Across that entire range of temperature, -20° F to +160° F, the ammo loaded with AR-Comp showed a variation of only 20 fps in muzzle velocity. The primary bullet type tested was a 77gr .224 bullet and the secondary was a 175gr .308 bullet.

Burn Rate Like Varget: Though this is a reformulation of Reloder 15, the burn rate of AR-Comp is slightly faster than Reloder 15. Alliant told us: “Reloder 15 is slightly slower, in burn rate, than Varget. The new AR-Comp, with the enhancements, ended up slightly faster than Reloder 15, so it is now very close to Varget in burn rate”. This is the result of the “tuning” of the powder to be much less temp-sensitive.

Meters Like Reloder 15: AR-Comp is a small-kernel, double-base extruded powder like Reloder 15, so it will continue to meter just like Reloder 15. The load density should be the same as Reloder 15.

Loaded Ammo: We asked if any manufacturer will be using AR-Comp in loaded ammo. Dick told us that he is “not allowed to release that information at this time”. Draw your own conclusions, but remember that Alliant is owned by ATK, which makes Federal rifle ammo.

Available in Summer 2011: Allliant hopes to ship AR-Comp in “June or July” of 2011, provided the DOT Classification process moves at a normal schedule. The powder is ready to go, Alliant is just waiting on the DOT to provide shipping authorization.

Reloder 15 Will Stay in Production: Fans of Alliant’s Reloder 15 don’t need to worry. Alliant will keep Reloder 15 in production. “We don’t drop powder lines”, said Quesenberry.

AR-Comp First in Series of New Alliant Temp-Stable Powders
Alliant has been working on AR-Comp for quite some time. This represents a major evolution for Alliant’s powder line. AR-Comp will be the first in a series of “new generation” temp-stable powders from Alliant. Quesenberry noted: “Our goal was to provide a powder that offers stable pressures in all temperatures. Shooters want to be able to stay with the same load in winter and in summer, in cold or in hot conditions.”

Quesenberry added: “We’ve been working on this quite a while. AR-Comp is the first example and we hope to extend this to other rifle powders. It’s a tough job. You have to balance the performance carefully. If you tweak it one way, say to improve the low temp performance, you lose something at the upper end. If you tweak it for the top end, you loose something at the bottom. You have to hit that balance. We worked very hard to do just that and we think shooters will be impressed with the results.”

Permalink Bullets, Brass, Ammo, New Product No Comments »
May 19th, 2010

New Annealing Machines from Ballistics Edge Mfg.

model 200 annealing machineForum member and long-range shooter Jerry Brandon has launched a new company, Ballistics Edge Mfg., which produces cartridge annealing machines for use by home reloaders. Brandon, a talented designer and fabricator, first tried annealing to maintain the quality of his own match brass. Brandon then built and tested a series of prototype annealing machines, working with a variety of brass sizes. Now Ballistics Edge Mfg. offers a full line of four annealing machines: the manually-operated Model 200 ($250), the motorized twin-torch Model 300 ($345), the motorized triple-torch Model 350 ($395), and the motorized Model 400 ($475), a beautifully-machined carousel design.

Brandon’s most versatile machine, and the one he recommends for annealing both normal- and magnum-sized cases, is the Model 350. Like the Model 300, the Model 350 features all-metal construction and motorized case transport. The Model 350 uses three torches rather than the Model 300’s two. The triple-torch system does a better job heating the large-diameter necks on .338, .416 and .50-caliber cases. The triple-torch design also ensures fast, uniform heating of the case-necks on smaller cases. The video below shows the Model 350 in action, annealing jumbo-sized .50 BMG cases.

YouTube Preview Image

model 200 annealing machineFor PPC, 6mmBR, and .308-sized cases, you can use the Model 200, the Model 300, or the Model 400. The Model 200 is a simple, one-at-a-time annealer that works remarkably well using a sliding arm. Simply slide the case into the flame, then slide it out after the required dwell time. For the average reloader, the Model 200 may be more than adequate. If, however, you plan to anneal hundreds of cases a week, you may want to consider the beautifully-machined Model 400 carousel, which will anneal 100 cases in less than 15 minutes. The Model 400 features both .308-size and magnum/ultra magnum-size holes to accept both .47X and .56X diameter cases. Just choose the correct size hole and adjust the torch height to match your case. The .75″-thick shell-plate top acts as a heat-sink to protect the lower case body. View the Model 400 carousel annealer in the video below.

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Ballistics Edge Website Offers Good Technical Advice on Annealing
Anyone interested in learning about cartridge annealing should visit www.AnnealingMachines.com, Jerry Brandon’s website. There you’ll find a helpful, authoritative discussion of annealing, including the all-important factors of time and temperature. As Brandon observes, much MISinformation about annealing can be found. Brandon will set you straight. Read Brandon’s How to Anneal article and you can avoid making costly (and potentially dangerous) mistakes, whether you anneal manually or use an annealing machine. In the video below, Jerry Brandon reviews the features of Ballistics Edge annealing machines. He also provides some good, basic advice for shooters who are looking to try their hand at annealing for the first time.

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Permalink Bullets, Brass, Ammo, New Product, Reloading 1 Comment »
November 4th, 2009

Affordable Timex Offers Temp, Air Pressure, Timer Functions

Temperature, Atmospheric Pressure, and Altitude — all these things can and do affect bullet ballistics. Moreover, temperature changes can alter powder performance and chamber pressures. The smart reloader takes the predicted ambient temperature into account. And when calculating your come-ups and windage click values, you need to factor in Temperature, Air Pressure, AND Altitude.

Kestrel 4000 Weather TrackerHow do you keep track of these important variables when you’re shooting? The Kestrel 4000 Pocket Weather Tracker®, is compact and provides a wealth of information: atmospheric pressure, altitude, density altitude, temperature, humidity, wind speed, wind chill, dew point, and heat index. We like the Kestrels and recommend them. But at $279.00, a Kestrel 4000 is too expensive for many shooters.

Timex now offers a solution. Selling for about $60.00-$75.00 (street price), the Timex Expedition® Adventure Tech™ watch (item T41501EA) displays Altitude, Barometric Pressure, and Temperature (ABT). The thermometer function records temps from 14° F to 140° F. The Altimeter reads from -2,296 feet to +29,520 feet with 10-foot resolution. The Barometer tracks current and sea level pressure, and provides a graph of pressure changes over time.

Timex Altimeter Watch

Encased in a stainless housing with a resin band, the Timex watch is water resistant to 50 meters, and offers many other nice features, including dual time zones, countdown timer, alarm, and backlit nightlight (very handy). The countdown timer is very easy to set and activate; and yes the timer can be used effectively in a shooting match.

There are other quality watches, such as the Suunto Core, that provide Altitude, Atmospheric Pressure, and Temperature read-outs. But, at under $70.00, the Timex is one-fourth the price of the Suunto. Amazon.com is currently offering the Timex Temp/Altitude/Barometer watch for $62.88. It is offered with a silver band as well as the black shown above.

Useful Tool or Just Another Gadget?
Is this watch really useful or just another piece of male jewelry? Well just last week a friend was developing loads and he wanted to input the ambient temperature, and current air pressure. The Timex gave us the desired data. (Note: it’s best to take the watch off your arm when gauging air temp). For this editor, the Timex ABT watch is a useful tool. I bought one and use it during load development and when shooting competitively. Negatives? Well the Timex IS big and thick, really thick, but then it’s much handier than carrying BOTH a digital thermometer/altimeter AND a separate count-down timer.

Here’s an owner’s review: “I have been through a Nike ABT, a Swiss Army ABT, and a High Gear ABT watch this year alone. None of them, which cost quite a bit more, have been as accurate and durable as this Timex. It has a better fit, was easy to use and read and just plain ‘on the money’ as far as forecasting weather and altitude. Also, I have not had to take it off my arm for 10-15 mins to get a decent temperature rating. It has always been within 1-3 degrees of actual temp. And I live in the Carribean in a tropical climate… so, for it to be this accurate is a statement in itself.”

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September 20th, 2008

Keep That Barrel Cool — Temp Strips Display Barrel Temperature

Bad things can happen if your barrel gets too hot. First, with some barrels, the point of impact (POI) will shift or “walk” as the barrel heats up excessively. Second, even if the POI doesn’t change, the groups can open up dramatically when the barrel gets too hot. Third, if the barrel is very hot, the chamber will transfer heat to your loaded cartridge, which can lead to pressure issues. Finally, hot barrels wear out faster. This is a very real concern, particularly for varmint shooters who may shoot hundreds of rounds in a day. For this reason, many varminters switch among various guns, never letting a particular barrel get too hot.

Bar-L shooting temp strips

How do you monitor your barrel temperature other than guessing by “feel”? Neconos.com offers Bar-L Benchrest strips that visually display heat readings from 86 to 140 degrees. Think of these strips as compact, unbreakable thermometers. With adhesive backing, they can also be used to monitor barrel heating. Put a strip on the side of the barrel and the barrel’s temp will be indicated by a stripe that changes from black to green. There is also a “general purpose” strip that reads to 196 degrees (bottom row). The Benchrest strip (86F to 140F) is in the middle. Bar-L temp strips cost $9.00, or $25.00 for a 3-pack.

Value-Priced Temp Strip 10-packs
If you have many rifles, McMaster.com (a large industrial supply house) offers the same reversible, 7 temperature, 86F to 140F strip (item 59535K13) for $11.86 per pack of ten (10) strips. That’s an excellent value. Thanks to reader Josh B. for this tip!

Controlling Ammo Temperature is Important Too
Keeping your loaded cases at a controlled temperature is vital for maintaining good ES and case life. At a late summer varmint match we observed pressure signs with cases that had been sitting in direct sunlight for about 15 minutes. As we were running a “moderate” RL15 load, the pressure indications were surprising. Testing over a chronograph, cases that had been sitting in direct sunlight showed velocities up to 70 fps higher than those that had been kept in the shade. Using QuickLoad’s temperature function, we calculated from the rise in velocities that case pressures had increased by over 4,000 psi–just from 15-20 minutes in direct sunlight!

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June 21st, 2008

Timex Altimeter, Barometer, Thermometer Watch

Temperature, Atmospheric Pressure, and Altitude — all these things can and do affect bullet ballistics. Moreover, temperature changes can alter powder performance and chamber pressures. The smart reloader takes the predicted ambient temperature into account. And when calculating your come-ups and windage click values, you need to factor in Temperature, Air Pressure, AND Altitude.

Kestrel 4000 Weather TrackerHow do you keep track of these important variables when you’re shooting? The Kestrel 4000 Pocket Weather Tracker®, is compact and provides a wealth of information: atmospheric pressure, altitude, density altitude, temperature, humidity, wind speed, wind chill, dew point, and heat index. We like the Kestrels and recommend them. But at $279.00, a Kestrel 4000 is too expensive for many shooters.

Timex now offers a solution. For about $56.00-$80.00 street price, the Timex Expedition® Adventure Tech™ watch (item T41501EA) displays Altitude, Barometric Pressure, and Temperature (ABT). The thermometer function records temps from 14° F to 140° F. The Altimeter reads from -2,296 feet to +29,520 feet with 10-foot resolution. The Barometer tracks current and sea level pressure, and provides a graph of pressure changes over time.

Timex Altimeter Watch

Encased in a stainless housing with a resin band, the Timex watch is water resistant to 50 meters, and offers many other nice features, including dual time zones, countdown timer, alarm, and backlit nightlight (very handy).

There are other quality watches, such as the Suunto Core, that provide Altitude, Atmospheric Pressure, and Temperature read-outs. But, at under $70 street price, the Timex costs one-fourth the price of the Suunto. Amazon.com is currently offering the Timex Temp/Altitude/Barometer watch for $55.97 – $79.95 (depending on source). It is offered with a silver band as well as the black shown above.

Useful Tool or Just Another Gadget?
Is this watch really useful or just another piece of male jewelry? Well just last week a friend was developing loads for his PPC. While chronographing his loads he wanted to input the ambient temperature, and current air pressure in his log. We just had to guess on those numbers. It felt like 90°+, but it may have been in the mid-eighties. With the Timex we’d have had reliable data (Note: it’s best to take the watch off your arm when gauging air temp). For this editor, the Timex ABT watch is a useful tool. I bought one and will be using it during load development and when shooting competitively.

Here’s an owner’s review: “I have been through a Nike ABT, a Swiss Army ABT, and a High Gear ABT watch this year alone. None of them, which cost quite a bit more, have been as accurate and durable as this Timex. It has a better fit, was easy to use and read and just plain ‘on the money’ as far as forecasting weather and altitude. Also, I have not had to take it off my arm for 10-15 mins to get a decent temperature rating. It has always been within 1-3 degrees of actual temp. And I live in the Carribean in a tropical climate… so, for it to be this accurate is a statement in itself.”

And here’s an interesting comment from one purchaser: “I bought this watch to set the jetting on my racing go kart. I needed to know field elevation, and temperature. Plus changes in barometric pressure as the day went on. Most teams use a weather station and computer that cost over $700 for this purpose. My watch and accompanying chart (for the motor) has given me the same results.” If this watch works for racers, it can work for our “internal combustion” precision bullet-launching machines as well.

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