May 17th, 2018

Powder Temp Stability — IMR Enduron vs. H4350 and Varget

powder gunpowder temperature sensivity temp stability Hodgdon Extreme Varget H4350 IMR Enduron 4451 4166

A couple seasons back, PrecisionRifleBlog.com (PRB) published a significant field test of powder temperature stability. The test was designed to quantify the temperature stability of Hodgdon H4350 and Varget powders compared to IMR’s Enduron line of powders, specifically IMR 4166 and 4451. The results were very interesting, to say the least…

Hodgdon Extreme Series powders have attracted quite a fan base, with over 90% of the top shooters in the Precision Rifle Series choosing to run one of those powders. IMR offers a modern line of powders “with Enduron Technology” — which is also marketed to have “extreme temperature stability”. Sounds familiar! These new powders should compete directly with the Hodgdon Extreme Series, which gives shooters more temp-stable powder options to consider.

CLICK HERE to Read Full Powder Temperature Stability Test on Precision RifleBlog.com.

The top shooters in the PRS and veteran long-range shooters in other disciplines have learned to value a temperature-stable powder. That’s because a change in temperature can affect the trajectory or “flight path” of the bullet in two well-known ways:

1. Assuming all other environmental conditions remain the same, an increase in air temperature will cause a flatter trajectory due to a lower air density (easier for the bullet to cut through the air).

2. The same increase in temperature also causes the nitrocellulose-based powder inside the cartridge to burn at a higher rate, producing approximately four times the Point of Impact (POI) shift than just air temperature alone. (SEE: Temperature Effects On Zero on KestrelMeters.com.)

“The initial heat condition of your powder will affect the burn rate,” Bryan Litz explained at a recent Applied Ballistics Seminar. That means swings in ambient outside temperature can affect your internal ballistics, which will directly affect your muzzle velocity, which will change your bullet’s trajectory. Some powders are more affected by changes in temperature than others. So if your goal is first-shot hits and you may shoot in a variety of conditions — you should care about temperature stable powders.

The folks at PrecisionRifleBlog.com meticulously loaded 6.5×47 Lapua ammo with each powder using some of the best equipment available. This included the top-of-the-line Prometheus Gen II Powder Scale, which is capable of loading to the nearest kernel of powder. This ensured the powder charges were identical for each round of ammo. PRB’s testers explain the full set of equipment and steps in their loading process in the Full Test Report.

Magnetospeeed LabRadar chronograph chrono powder gunpowder temperature sensivity temp stability Hodgdon Extreme Varget H4350 IMR Enduron 4451 4166

Once they had a couple dozen rounds loaded with each powder, they went and shot them with each powder at 25° F, 65° F, and 140° F. The muzzle velocity of each shot was recorded using BOTH a LabRadar Doppler Radar and a MagnetoSpeed Chronograph. That provided two sets of velocity numbers. When placed and configured optimally, the LabRadar can measure muzzle velocity with +/- 0.1% accuracy, according to the manufacturer.

Here are the results from the PRB Powder Temp Stability Tests:

Magnetospeeed LabRadar chronograph chrono powder gunpowder temperature sensivity temp stability Hodgdon Extreme Varget H4350 IMR Enduron 4451 4166

You can see Hodgdon H4350 had the least variance in muzzle velocity, with just 25 fps over the 115° swing in temperature! That is very, very low. Hodgdon Varget was the second least temperature sensitive powder in this test, with 46 fps of variance in muzzle velocity between temperatures of 25° F and 140° F. IMR 4166 performed very similar to Varget, and proved to be fairly insensitive to large swings in temperature. IMR 4451 had the largest swing in muzzle velocity of the powders tested, but keep in mind just 68 fps over 115° F swing is still a good performance.

Most powders aren’t specially formulated to be temperature stable. So they would likely show much larger swings than what these four top-performing powders showed. However, Alliant’s relatively new Reloder 16 is an extremely temp-stable powder, with a burn rate that is a close match to H4350. Many F-Open competitors are now using Reloder 16 with considerable success.

PRB’s test team also noticed other interesting trends in the data. For example, variation in velocity does NOT appear to be linear across the full range of temperatures. By that, they mean the change per degree from 20° to 65° might be smaller or larger than the change per degree from 65° to 140°.

PRB’s testers talk about those things, provide a few other insightful views of the data, and discuss tools that can help you manage temp/muzzle velocity in the field in their full post. You can find that here: http://precisionrifleblog.com/2016/06/19/powder-temp-stability-hodgdon-extreme-vs-imr-enduron/

Permalink News, Reloading, Tech Tip No Comments »
July 19th, 2016

Powder Temp Stability: IMR Enduron vs. Hodgdon Extreme

powder gunpowder temperature sensivity temp stability Hodgdon Extreme Varget H4350 IMR Enduron 4451 4166

PrecisionRifleBlog.com (PRB) recently published results from a field test PRB conducted to quantify the temperature stability of the popular Hodgdon H4350 and Varget powders and compare those to IMR’s new Enduron line of powders, specifically IMR 4166 and 4451.

Hodgdon Extreme Series powders have attracted quite a fan base, with over 90% of the top shooters in the Precision Rifle Series choosing to run one of those powders. IMR recently released a new line of powders “with Enduron Technology” — which is also marketed to have “extreme temperature stability”. Sounds familiar! These new powders should compete directly with the Hodgdon Extreme Series, which gives shooters more temp-stable powder options to consider.

CLICK HERE to Read Full Powder Temperature Stability Test on Precision RifleBlog.com.

The top shooters in the PRS and veteran long-range shooters in other disciplines have learned to value a temperature-stable powder. That’s because a change in temperature can affect the trajectory or “flight path” of the bullet in two well-known ways:

1. Assuming all other environmental conditions remain the same, an increase in air temperature will cause a flatter trajectory due to a lower air density (easier for the bullet to cut through the air).

2. The same increase in temperature also causes the nitrocellulose-based powder inside the cartridge to burn at a higher rate, producing approximately four times the Point of Impact (POI) shift than just air temperature alone. (SEE: Temperature Effects On Zero on KestrelMeters.com.)

“The initial heat condition of your powder will affect the burn rate,” Bryan Litz explained at a recent Applied Ballistics Seminar. That means swings in ambient outside temperature can affect your internal ballistics, which will directly affect your muzzle velocity, which will change your bullet’s trajectory. Some powders are more affected by changes in temperature than others. So if your goal is first-shot hits and you may shoot in a variety of conditions — you should care about temperature stable powders.

Magnetospeeed LabRadar chronograph chrono powder gunpowder temperature sensivity temp stability Hodgdon Extreme Varget H4350 IMR Enduron 4451 4166

The folks at PrecisionRifleBlog.com meticulously loaded 6.5×47 Lapua ammo with each powder using some of the best equipment available. This included the top-of-the-line Prometheus Gen II Powder Scale, which is capable of loading to the nearest kernel of powder. This ensured the powder charges were identical for each round of ammo. PRB’s testers explain the full set of equipment and steps in their loading process in the Full Test Report.

Once they had a couple dozen rounds loaded with each powder, they went and shot them with each powder at 25° F, 65° F, and 140° F. The muzzle velocity of each shot was recorded using both a LabRadar Doppler Radar and a MagnetoSpeed Chronograph. The LabRadar is a new type of device that allows you to measure muzzle velocity within at least +/- 0.1% of the reading.

Magnetospeeed LabRadar chronograph chrono powder gunpowder temperature sensivity temp stability Hodgdon Extreme Varget H4350 IMR Enduron 4451 4166

Here are the results from the PRB Powder Temp Stability Tests:

Magnetospeeed LabRadar chronograph chrono powder gunpowder temperature sensivity temp stability Hodgdon Extreme Varget H4350 IMR Enduron 4451 4166

You can see Hodgdon H4350 had the least variance in muzzle velocity, with just 25 fps over the 115° swing in temperature! That is very, very low. Hodgdon Varget was the second least temperature sensitive powder in this test, with 46 fps of variance in muzzle velocity between temperatures of 25° F and 140° F. IMR 4166 performed very similar to Varget, and proved to be fairly insensitive to large swings in temperature. IMR 4451 had the largest swing in muzzle velocity of the powders tested, but keep in mind just 68 fps over 115° F swing is still a good performance.

Most powders aren’t specially formulated to be temperature stable. So they would likely show much larger swings than what these four top-performing powders showed.

PRB’s test team also noticed other interesting trends in the data. For example, variation in velocity does NOT appear to be linear across the full range of temperatures. By that, they mean the change per degree from 20° to 65° might be smaller or larger than the change per degree from 65° to 140°.

PRB’s testers talk about those things, provide a few other insightful views of the data, and discuss tools that can help you manage temp/muzzle velocity in the field in their full post. You can find that here: http://precisionrifleblog.com/2016/06/19/powder-temp-stability-hodgdon-extreme-vs-imr-enduron/

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June 10th, 2016

Guide to IMR’s Enduron Powders — What You Need to Know

IMR Enduron Powders 4955 4451 4166 7977

IMR® Legendary Powders now offers four (4) Enduron powders: IMR 4166, IMR 4451, IMR 4955, and IMR 7977. Shooters looking for readily-available alternatives to hard-to-find extruded powders should definitely check out the Enduron line-up. Precision shooters will find an Enduron option well-suited to most of the popular precision cartridge types. For example, IMR 4166 is a good replacement for Hodgdon Varget (commonly used in the .223 Rem, 6mmBR and .308 Win), while IMR 4955 is a fine substitute for H4831 (favored by F-Open shooters for the .284 Win and 7mm WSM cartridges).

enduron IMR Powder Hodgdon extreme

Modern Powder Technology for Enhanced Performance

The technology in IMR’s Enduron line of powders provides four very important qualities that enhance both in-gun and downrange performance.

IMR Enduron Powders 4955 4451 4166 7977

Copper fouling reduction – these powders contain an additive that drastically reduces copper fouling in the gun barrel. Copper fouling should be minimal, allowing shooters to spend more time shooting and less time cleaning a rifle to retain accuracy.

Temperature change stability – the Enduron line is insensitive to temperature changes. Whether a rifle is sighted in during the heat of summer, hunted in a November snowstorm or hunting multiple locations with drastic temperature swings, point of impact with ammunition loaded with Enduron technology will be very consistent.

Optimal load density - Enduron powders provide optimal load density, assisting in maintaining low standard deviations in velocity and pressure, a key feature for top accuracy.

Environmentally friendly - Enduron technology is environmentally friendly, crafted using raw materials that are not harmful to the environment.

The Enduron Line-Up of Four Powders

IMR now offers four Enduron powders that cover a broad range of burn rates. They are suitable for a wide variety of cartridges, from small varmint cartridges all the way up to the .338 Lapua Magnum.

IMR Enduron Powders

IMR 4166 possesses the fastest burn rate in the Enduron lineup. It is the perfect burn speed for cartridges such as .308 Win, 7.62mm NATO, 22-250 Rem and 257 Roberts. A versatile, match-grade propellant, IMR 4166 is comparable to Hodgdon® Varget.

IMR 4451 is a mid-range burn speed powder, ideally suited for cartridges such as .270 Winchester, .30-06 and 300 Winchester Short Magnum. This powder is comparable to Hodgdon H4350.

IMR 4955 is a medium burn speed powder, falling in between IMR 4451 and IMR 7977 in burn speed. It provides top performance in big game cartridges such as 25-06, 280 Remington and 300 Winchester Magnum. This powder is comparable to Hodgdon H4831.

IMR 7977 has the slowest burn rate among the Enduron Technology powders. Its loading density is perfect for magnum cartridges and contributes to superb uniformity, yielding outstanding performance in 300 Winchester Magnum, 7MM Remington Magnum and .338 Lapua Magnum. IMR 7977 is comparable to Hodgdon H1000.

The Enduron Technology powders are available in one-pound (1 lb) and eight-pound (8-lb) containers from quality reloading retailers. Learn more about Enduron powders at www.enduronimr.com. For info on other IMR powders, visit www.imrpowder.com.

IMR Enduron Powders 4955 4451 4166 7977

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November 7th, 2014

Powder Valley has new IMR 4166 Powder in Stock

IMR Enduron powder 4166 Varget RL15Powder Valley Inc. (PVI) now has the new IMR 4166 powder. This is an all-new extruded powder with a burn rate similar to Hodgdon Varget. It is expected to perform well in the .308 Winchester and in 6mm cartridges running the heavier (95-107gr) projectiles. IMR’s press release states: “IMR 4166 [has] a perfect burn speed for cartridges like the 308 Win/7.62mm NATO, 22-250 Remington, 257 Roberts and dozens more.”

IMR 4166 is one of the new Enduron family of propellants. It is formulated to reduce fouling and to be stable across a wide temperature range. If you commonly use Varget, Alliant Reloder 15, Norma 203B, IMR 8208 XBR, or Vihtavuori N140, you might want to try IMR 4166. It is available right now at Powder Valley in both one-pound ($25.45) and 8-pound ($182.75) containers:

IMR4166-01: IMR 4166 – 1 LB. — $25.45
IMR4166-08: IMR 4166 – 8 LBS. — $182.75

For more information and IMR 4166 LOAD DATA visit imrpowder.com or check the 2015 Hodgdon Annual Manual. Load data should be forthcoming pretty soon.

Permalink New Product, Reloading 2 Comments »
October 21st, 2014

IMR Introduces New Enduron Powders: 4166, 4451, 7977

IMR Hodgdon Enduron PowderIMR is bringing out a new series of advanced-formulation extruded powders. In 2015, IMR will introduce three (3) new Enduron powders: IMR 4166, IMR 4451, and IMR 7977. The new line of IMR Enduron powders feature small kernels for easy metering, plus a built-in copper fouling eliminator. IMR claims that Enduron powders are not sensitive to temperature changes. If this is true, these powders should prove popular, particularly IMR 4166 which seems to be in the Varget/Reloder 15 burn-rate range. With Varget so hard to find, if IMR 4166 proves accurate (and available) we might see many .308 Win shooters make the switch. IMR states that IMR 4166 is a “versatile, match grade propellant”. We’ve been quite pleased with IMR 8208 XBR as a Varget alternative. IMR 8208 XBR is accurate, clean-burning, and offers good velocity. Perhaps the new IMR 4166 will be as good or better.

When will Enduron powders appear on dealers’ shelves? Hodgdon Powder Co., distributors of Hodgdon, IMR, and Winchester powders, says that: “The new IMR Enduron™ Technology powders will be available at dealers in early 2015 in 1-pound and 8-pound containers.” For more information and Enduron LOAD DATA visit imrpowder.com or check the 2015 Hodgdon Annual Manual.

IMR’s press release provides these descriptions of the new Enduron propellants:

IMR 4166 is the first in the series of Enduron™ propellants. It’s a perfect burn speed for cartridges like the 308 Win/7.62mm NATO, 22-250 Remington, 257 Roberts and dozens more.

IMR 4451 Another new Enduron powder that gives top performance in the venerable .30-06, 270 Winchester, and 300 Winchester Short Magnum, to name just a few. This propellant is ideally suited for many mid-range burn speed cartridges.

IMR 7977 is the slowest burn rate Enduron Technology powder. It is a true magnum cartridge propellant with outstanding performance in such cartridges as the .300 Winchester Magnum, 7mm Remington Magnum, .338 Lapua and more.

IMR Hodgdon Enduron Powder

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