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August 31st, 2015
 While Varget and Reloder 15 remain in short supply, you can often find IMR 4320 powder back in the shelves of local gun stores. IMR describes IMR 4320 as follows: “Short granulation, easy metering, and perfect for the 223 Remington, 22-250 Remington, 250 Savage and other medium burn rate cartridges.” This older-generation powder is more temp sensitive than the Hodgdon Extreme propellants, but in the right application, it looks to be a viable alternative for folks who can’t source Varget, Reloder 15, and even H4895.
IMR 4320 Shoots Well in the .308 Winchester
A while back, GS Arizona wrote an excellent Riflemans Journal article, IMR 4320 — the Forgotten Powder. GS developed IMR 4320 loads for his .308 Win Palma rifle and competed with IMR 4320-powered ammo at long range matches. He concluded that: “[IMR 4320] appears to be a very useful alternative to some of the harder-to-get powders. The load is working extremely well at 1000 yards. In the [2009] Arizona Palma State Championship, several high placing competitors were using the 4320 load. We got sub X-Ring elevation at 1000 yards from several rifles, and that’s all I’m looking for in a Palma load.”
IMR 4320 Works for Dasher Shooter
Forum member FalconPilot shoots a 6mm Dasher with Berger 105gr Hybrids. Looking for an alternative to Varget, he decided to give IMR 4320 a try. The results were good. FalconPilot reports: “I’ve been looking for other options (besides Reloder 15, which I love, but it’s really dirty). While at a gun shop in Ohio, I ran across 8 pounds of IMR 4320. I had never even heard of it, much less tried it. Getting ready for upcoming mid-range shoots, I loaded five rounds with IMR 4320 to the exact same specs as my winning Varget loads for the 6mm Dasher. This recipe was 32.7 grains of powder, Wolf SMR primer, Berger Hybrid 105 jumped fifty thousandths.” Falcon pilot tested his IMR 4320 load at 600 yards:
As you can see from the photo at the top of this article, FalconPilot had good results — a 1.5″ group at 600 yards. He reports: “This group was shoot during the middle of the day, mirage bad, scope set to 25X. It looks like IMR 4320 is a [very close] replacement for Varget… with a tad bit slower burn rate.” FalconPilot tell us the accuracy with IMR 4320 rivals the best he has gotten with Varget: “This gun has always shot under 2 inches [for 5 shots] at 600 yards, and most of time shoots 1.5 to 1.7 inches.”
For comparison purposes, here are Heat of Explosion and Burn Rate values from QuickLOAD for IMR 4320, and for the popular Reloder 15 and Varget powders. You can see that these powders have similar characteristics “by the numbers”:
| Manufacturer |
Powder Brand |
Heat of Explosion |
Burning Rate Factor |
| IMR |
4320
| 3890 |
0.5920 |
| Alliant |
Reloder 15 |
3990 |
0.5200 |
| Hodgdon (ADI) |
Varget |
4050 |
0.6150 |
|
WARNING — When changing from one powder to another, always start with manufacturer’s stated load data. Start low and work up incrementally. Never assume that loads will be equivalent from one powder to another, even powders with similar burn rates.
What Other Forum Members Say:
I was using IMR 4320 in the mid 70s in my .222 Rem. Darned great powder and I never had a load that was not accurate from the .222 to .30-06 with that powder. — 5Spd
A fine powder overshadowed by the nouveau wave of “gotta have the newest — make me a better shot” powders. Try 4320 in a 22-250 — what a well-kept secret! IMR 4320 meters very well and is a flexible alternative to many of the hard-to-find powders so much in demand. — AreaOne
IMR 4320 was my “go to” powder in my .223 for many many years. This powder and Winchester 55gr soft point bulk bullets (the cheapest bullet I could buy at the time) accounted for thousands of prairie dogs, coyotes, and anything else that needed shooting. I still use IMR 4320 in some .223 loads and am very happy with it still. — pdog2062
I’ve been using it in a .308 Win for several years. I think it is very sensitive to temperature and always waited till the last minute to load my ammo with a close eye on the weekend forecast at the range. IMR 4320 Works pretty good for 155gr Palma and 168gr Hybrid [bullets] in my .308. — JayC
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November 20th, 2012
 How much does it cost you to send a round downrange? Ask most shooters this question and they’ll start adding up the cost of components: bullets, powder, and primers. Then they’ll figure in the cost of brass, divided by the number of times the cases are reloaded.
For a 6BR shooting match bullets, match-grade primers, and 30 grains of powder, in brass reloaded ten times, this basic calculation gives us a cost per shot of $0.51 (fifty-one cents):
Bullet $0.33 (Berger 105 VLD) Grafs.com
Primer $0.02 (Tula/Wolf SmR magnum) PVI
Powder $0.08 (Reloder 15 @ $19.15/lb) PVI
Brass $0.08 (Lapua @ $82.30/100, 10 reloads)
Total = $0.51 per round
NOTE: If you shoot a larger caliber that burns more powder, and uses more expensive bullets and/or brass, your total cost per round will be higher than $0.51.
$1.00 Per Shot True Cost? Yikes!
OK, we’ve seen that it costs about $0.51 per round to shoot a 6BR. Right?
Wrong! — What if we told you that your ACTUAL cost per round might be closer to double that number? How can that be? Well… you haven’t accounted for the cost of your barrel. Every round you fire down that tube expends some of the barrel’s finite life. If, like some short-range PPC shooters, you replace barrels every 700 or 800 rounds, you need to add $0.60 to $0.70 per round for “barrel cost.” That can effectively double your cost per round, taking it well past the dollar per shot mark.
Calculating Barrel Cost Per Shot
In the table below, we calculate your barrel cost per shot, based on various expected barrel lifespans.
 As noted above, a PPC barrel is typically replaced at 700-800 rounds. A 6.5-284 barrel can last 1200+ rounds, but it might need replacement after 1000 rounds or less. A 6BR barrel should give 2000-2600 rounds of accurate life, and a .308 Win barrel could remain competitive for 4,000 rounds or more.
The table below shows your barrel cost per shot, based on various “useful lives.” We assume that a custom barrel costs $540.00 total to replace. This includes $300.00 for the barrel itself, $200.00 for chambering/fitting (conservative number), and $40.00 in 2-way shipping costs. These are typical costs shooters will encounter when ordering a rebarreling job.
The numbers are interesting. If you get 2000 rounds on your barrel instead of 1000, you save $0.27 per shot. However, extending barrel life from 2000 to 3000 rounds only saves you $0.09 per round. The longer you keep your barrel the more you save, but the savings per shot decreases as the round count increases.
How to Reduce Your TRUE Cost per Round
What does this tell us? First, in figuring your annual shooting budget, you need to consider the true cost per round, including barrel cost. Second, if you want to keep your true costs under control, you need to extend your barrel life. This can be accomplished in many ways. First, you may find that switching to a different powder reduces throat erosion. Second, if you’re able to slow down your shooting pace, this can reduce barrel heat, which can extend barrel life. (A varminter in the field is well-advised to switch rifles, or switch barrels, when the barrel gets very hot from extended shot strings.) Third, modifying your cleaning methods can also extend the life of your barrel. Use solvents that reduce the need for aggressive brushing, and try to minimize the use of abrasives. Also, always use a properly fitting bore guide. Many barrels have been prematurely worn out from improper cleaning techniques.
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May 25th, 2011
 Alliant is introducing a new extruded powder, AR-Comp. 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. The main difference between AR-Comp and Reloder 15, is the AR-Comp has a slightly faster burn rate, and AR-Comp is much LESS Sensitive to temperature changes. 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.
AR-Comp should be at Grafs.com in a Couple Weeks
Here’s the good news — Alliant will start shipping AR-Comp to Grafs.com later this week. Dick Quesenberry, Alliant Powder Product Manager, told us: “I just received the AR-Comp packaging labels and we hope to send off the first shipments to Grafs this week.” With transit time, expect the powder to be available from Grafs.com by the second week of June. You can go ahead and place advance orders for 1-lb and 8-lb containers of AR-Comp on the Grafs.com website.
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.
AR-Comp First in Series of New Alliant Temp-Stable Powders
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. We worked very hard to do just that and we think shooters will be impressed with the results.”
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.
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March 1st, 2011
Here’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.”
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February 26th, 2011
Here’s important news for handloaders. Alliant Powder has introduced a new medium-burn-rate powder: AR-Comp™. This new powder was developed specifically for AR-style rifles. Alliant says that AR-Comp powder is “ideally suited for heavy .223 and .308 match bullets”. We presume, from that description, that the powder will have a burn rate similar to Varget. The AR-Comp powder, produced in Sweden by Bofors Nobel, is an enhanced temp-insensitive reformulation of Reloder 15. The burn rate is slightly faster than Reloder 15, according to Alliant.
Alliant Claims AR-Comp is NOT Temp-Sensitive
We have limited information about AR-Comp, and we have not yet been supplied with a test sample. We have confirmed is a double-base extruded powder, and is an upgraded version of the Reloder 15 formulation. Alliant claims the powder meters very well and delivers “consistent pressures and velocities across temperature extremes”. This new powder is supposed to be very uniform from lot to lot. That would be great — if it is true — but only time will tell.
We will try to get a sample of AR-Comp soon and test it in both .223 Rem and .308 Win rifles. We suspect, if AR-Comp suits both the .223 Rem and .308 Win, it should work well in the 6mmBR and 6.5×47 Lapua cartridges as well. Stay tuned — we hope to have more info next week. AR-Comp should be hitting the market in June or July, 2011, provided DOT Classification goes smoothly. It will be offered in both one-pound (#150664) and 8-lb (#150665) containers.
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