AA # 5 / Accurate no 5

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For the Accurate home page,
Accurate Powder designations:

Since 2003/4 all prefixes of Accurate Powder designations such as “XMR” or “XMP” no longer apply.

Also the company name “Accurate Arms” or the abbreviation “AA” are not to be used.

The products are merely designated as “Accurate” or abbreviated with a single “A” prefix.

http://www.accuratepowder.com/

I still call it AA # X :scrutiny:
 
Treat them as 2 different powders.Probley not the same. On this board, someone ask about this brand of powders before, forget the number of the powder. Powder looked totally different in size and shape if i remember correctly. Photos were posted of each. Walkalong might remember.
 
243winxb,
AA#5, Accurate Number 5, Accurate #5 and Accurate Arms No.5 are all the same powders written differently. They have to be the same because #5 powder from Accurate Arms (now just Accurate) is #5 powder.
 
It is all the same, and the burn rate should be fairly consistent (has to be in cannister powders), but the density between those two lots of AA #5 I took a pic of are very different.

The AA data from early on is very consistent with their online PDF data today. The velocities per grain I have gotten in 9MM in limited testing has been very similar.
 
Here's a pic of AA#5 from the Czech Republic and the other AA#5 a date on the bottom 12/7/07 I am assuming US made ?
reloading 002.jpg
These two powders weight the same by volume and I did not notice a difference in way they shot, but they sure don't look the same.
 
I Stopped using accurate powders back in the late 90s to many wild swings from lot to lot and to many different suppliers over the years.
 
i wonder if the powder size differences has anything to do with the suspected kabooms using the aa#5 powder?
Click to expand...
Forensic Science Communications April 2002 — Volume 4 — Number 2


red bar graphic Research and Technology


The Manufacture of Smokeless Powders and their Forensic Analysis: A Brief Review

Robert M. Heramb
Graduate Student
Bruce R. McCord
Associate Professor of Analytical and Forensic Chemistry
Department of Chemistry
Ohio University
Athens, Ohio

Introduction.......Composition and Manufacturing.......Distribution.......Improvised Explosive Devices.......Analysis.......Conclusions.......References

Introduction

Smokeless powders are a class of propellants that were developed in the late 19th century to replace black powder. The term smokeless refers to the minimal residue left in the gun barrel following the use of smokeless powder. In forensic analysis, smokeless powders are often encountered as organic gunshot residue or as the explosive charge in improvised explosive devices.

All smokeless powders can be placed into one of three different classes according to the chemical composition of their primary energetic ingredients. A single-base powder contains nitrocellulose, whereas a double-base powder contains nitrocellulose and nitroglycerine. The energetic ingredients in triple-base powders are nitrocellulose, nitroglycerine, and nitroguanidine, but because triple-base powders are primarily used in large caliber munitions, they are difficult to obtain on the open market.

Composition and Manufacturing

The major classes of compounds in smokeless propellants include energetics, stabilizers, plasticizers, flash suppressants, deterrents, opacifiers, and dyes (Bender 1998; Radford Army Ammunition Plant 1987).

* Energetics facilitate the explosion. The base charge is nitrocellulose, a polymer that gives body to the powder and allows extrudability. The addition of nitroglycerine softens the propellant, raises the energy content, and reduces hygroscopicity. Adding nitroguanidine reduces flame temperature, embrittles the mixture at high concentration, and improves energy-flame temperature relationship.

* Stabilizers prevent the nitrocellulose and nitroglycerine from decomposing by neutralizing nitric and nitrous acids that are produced during decomposition. If the acids are not neutralized, they can catalyze further decomposition. Some of the more common stabilizers used to extend the safe life of the energetics are diphenylamine, methyl centralite, and ethyl centralite.

* Plasticizers reduce the need for volatile solvents necessary to colloid nitrocellulose, soften the propellant, and reduce hygroscopicity. Examples of plasticizers include nitroglycerine, dibutyl phthalate, dinitrotoluene, ethyl centralite, and triacetin.

* Flash suppressants interrupt free-radical chain reaction in muzzle gases and work against secondary flash. They are typically alkali or alkaline earth salts that either are contained in the formulation of the propellant or exist as separate granules.

* Deterrents coat the exterior of the propellant granules to reduce the initial burning rate on the surface as well as to reduce initial flame temperature and ignitability. The coating also broadens the pressure peak and increases efficiency. Deterrents may be a penetrating type such as Herkoteâ, dibutyl phthalate, dinitrotoluene, ethyl centralite, methyl centralite, or dioctyl phthalate; or an inhibitor type such as Vinsolâ resin.

* Opacifiers enhance reproducibility primarily in large grains and keep radiant heat from penetrating the surface. They may also enhance the burning rate. The most common opacifier is carbon black.

* Dyes are added mainly for identification purposes.

* Other ingredients may be one of the following:
o A graphite glaze used to coat the powder to improve flow and packing density as well as to reduce static sensitivity and increase conductivity
o Bore erosion coatings applied as a glaze to reduce heat transfer to the barrel, but uncommon in small-arms propellants
o Ignition aid coatings that are most commonly used in ball powders to improve surface oxygen balance

FIGURE 1: Image showing drawings of 6 shapes--a perforated disk, a disc, a tube, a rod, a ball, and a lamel.
Figure 1 Common smokeless powder morphologies Click to enlarge image.
Chemical composition is one important
characteristic defining smokeless propellants; however, another important characteristic is its morphology. Shape and size have a profound effect on the burning rate and power generation of a
powder (Meyer 1987).:) Common particle shapes of smokeless propellants include balls, discs, perforated discs, tubes, perforated tubes, and aggregates (Bureau of Alcohol, Tobacco and Firearms 1994; Selavka et al. 1989). A few common types of smokeless powder morphologies can be seen in Figure 1 (Bender 1998).

Morphology also lends clues to whether a powder is single- or double-base (Bender 1998). Most tube and cylindrical powders are single-base, with the exception of the Hercules Reloaderâseries. Disc powders, ball powders, and aggregates are double-base, with the exceptions being the PB and SR series powders manufactured by IMR Powder Company of Plattsburg, New York.

Except for ball powder, smokeless powder is manufactured by one of two general methods, differing in whether organic solvents are used in the process (Meyer 1987; Radford Army Ammunition Plant 1987). A single-base powder typically incorporates the use of organic solvents. Nitrocellulose of high- and low-nitrogen content are combined with volatile organic solvents, desired additives are blended with them, and the resulting mixture is shaped by extrusion and cut into specified lengths. The granules are screened to ensure consistency,:) and the solvents are removed. Various coatings, such as deterrents and graphite, are applied to the surface of the granules. The powder is dried and screened again, then blended to achieve homogeneity.

The manufacture of double-base powders requires the addition of nitroglycerine to the nitrocellulose. Two methods can be used. One method uses organic solvents, the other uses water. The organic solvent method mixes nitrocellulose and nitroglycerine with solvents and any desired additives to form a doughy mixture (Meyer 1987; National Research Council 1998; Radford Army Ammunition Plant 1987). The mixture is then pressed into blocks that can be fed into the extrusion press and cutting machine. The resulting granules are screened prior to solvent removal and the application of various coatings. The powder is dried, screened again, then blended to achieve homogeneity. The water method adds the nitroglycerine to a nitrocellulose water suspension to form a paste (Meyer 1987; Radford Army Ammunition Plant 1987). The water is removed by evaporation on hot rollers, then the dried powder is shaped by extrusion and cutting.

Triple-base powders use a solvent-based process similar to the double-base powder process (Meyer 1987; Radford Army Ammunition Plant 1987). Nitrocellulose and nitroglycerine are premixed with additives prior to the addition of a nitroguanidine solvent mixture. The nitroguanidine is incorporated into the overall mass without dissolving in the other materials. The final mixture is then extruded, cut, and dried.

The manufacture of smokeless ball powder requires a more specialized procedure (National Research Council 1998). Nitrocellulose, stabilizers, and solvents are blended into a dough, then extruded through a pelletizing plate and formed into spheres. The solvent is removed from the granules, and nitroglycerine is impregnated into the granules. The spheres are then coated with deterrents and flattened with rollers. Finally, an additional coating with graphite and flash suppressants is applied, and the batch is mixed to ensure homogeneity.

In the manufacturing process, smokeless powders are recycled and reworked (National Research Council 1998). When a powder within a batch is found to be unsatisfactory, it is removed and returned to the process for use in another lot. Manufacturers save money by recycling returns by distributors or the return of surplus or obsolete military powders. Hence, reworking and recycling the material assures good quality control of the final product, reduces costs by reusing materials, and reduces pollution by avoiding destruction by burning.

Distribution

The production of smokeless powders is big business in the United States, where approximately 10 million pounds of commercial smokeless powders are produced each year. Most of the powder is sold to the original-equipment manufacturers to be used for manufacturing ammunition. A large amount is sold to domestic and foreign militaries (National Research Council 1998). The rest is sold in individual canisters (ranging from ½-pound cans to 12- or 20-pound kegs) to gun stores or hunting and shooting clubs for hunters and target shooters who prefer to hand load their own ammunition.

There are several ways smokeless powders are distributed within the United States (National Research Council 1998). Some manufacturers, foreign or domestic, produce, package, and sell their own powders commercially. They may also sell in bulk to resellers and to original-equipment manufacturers that repackage and sell it under their own labels. The powder manufacturers and repackagers may disburse large quantities of canister powders to distributors who later sell to smaller distributors and wholesalers, who in turn, supply cans to dealers, gun shops, shooting clubs, and other retailers. At this point, consumers can purchase a 1-pound canister of powder for approximately $15 to $20 from a retailer, though the cost per pound can be cheaper if bought by the keg or acquired through a gun club (National Research Council 1998).

Manufacturers who produce smokeless powders for the U.S. military can distribute it either by selling the powder directly to the military or by selling them the preloaded ammunition. Powders can also be shipped to U.S. military subcontractors, foreign governments, or foreign loading companies for loading into military ammunition (National Research Council 1998).

Improvised Explosive Devices

An explosion is the result of energy-releasing reactions, generally accompanied by the creation of heat and gases (a notable exception is thermites). A distinguishing characteristic of an explosion is the rate at which the reaction proceeds. There are low-order and high-order explosives, based on the speed at which the explosives decompose. In low-order explosives, the process of decomposition, called the speed of deflagration or burning, produces heat, light, and a subsonic pressure wave. (The reaction speed of the deflagrating material is less than the speed of sound.) In high-order explosives, decomposition occurs at the speed of detonation, creating a supersonic shock wave that causes a virtually instantaneous buildup of heat and gases. Table 1 shows some differences in low-order and high-order explosives (Bureau of Alcohol, Tobacco and Firearms 1994; National Research Council 1998; Saferstein 1998).

For low-order explosives, rapid deflagration causes the production of large volumes of expanding gases at the origin of the explosion. The heat energy from the explosion also causes the gases to expand. When the explosive charge is confined in a closed container, the sudden buildup of expanding pressure exerts high pressure on the container walls causing the container to stretch, balloon, then burst, releasing fragments of debris to nearby surroundings. It is this fragmented debris that produces the fatal result following the deflagration of an improvised explosive device (Saferstein 1998).

The safest and most powerful low-order explosive is smokeless powder. These powders decompose at rates up to 1,000 meters per second and produce a propelling action that makes them suitable for use in ammunition. However, the slower burning rate of smokeless powder should not be underestimated. The explosive power of smokeless powder is extremely dangerous when confined to a small container. In addition, certain smokeless powders with a high-nitroglycerine concentration can be induced to detonate. On the other hand, high-order explosives do not need containment to demonstrate their explosive effects (Saferstein 1998). These materials detonate at rates from 1,000 to 8,500 meters per second, producing a shock wave with an outward rush of gases at supersonic speeds. This effect proves to be more destructive than the fragmented debris.

The typical smokeless powder improvised explosive device, a pipe bomb, is roughly 10 inches long and 1 inch wide and contains approximately ½ pound of powder. The materials used for these devices are cheap and readily obtainable at commercial establishments. Smokeless powder is attractive for use in improvised explosive devices, because it is readily available and has the potential for a powerful explosion when the powder is placed in a closed container (National Research Council 1998). Larger explosive devices usually use bulk materials such as ammonium nitrate and fuel oil, typically purchased in greater quantity at an even cheaper price.

Many types of containers are used in the construction of smokeless powder bombs (National Research Council 1998). Whereas metal pipes are most common, plastic pipes, cans, CO2 cartridges, and glass or plastic bottles have been used. These containers are often placed within larger packages for ease of transport and concealment.
FIGURE 2: Drawing of a tube of powder with screw-on end caps and a fuse.
Figure 2 Pipe Bomb Click to enlarge image.

Another important part of the powder bomb is the initiation system, which provides the impetus to start the powder burning within its container (National Research Council 1998). A few examples include cigarettes, matches, and safety fuses (Scott 1994; Stoffel 1972). Improvised explosive devices utilizing smokeless powders within a robust container often include an initiation system, as shown in Figure 2 (Scott 1994).

Using data from the National Research Council on reported actual and attempted bombings using propellants during the five-year period from 1992-1996, Table 2 illustrates an average of 653 incidents per year involving the use of black and smokeless powders. Bombs containing black or smokeless powders were responsible for an average yearly count of about 10 deaths, 83 injuries, and almost $1 million in property damage for each of the five years. Using the National Research Council's data involving devices filled with black and smokeless powders, Table 3 illustrates the number of actual bombings that caused at least one death, one injury, or a minimum of $1,000 in property damage, as well as attempted bombings aimed at significant targets (National Research Council 1998).

Analysis
FIGURE 3: A line graph with two prominent upward spikes.
Figure 3 Gradient HPLC analysis of an IMR 700X smokeless powder. Conditions Restek C-8 Column, 36-80% methanol/water gradient, 1 ml/min, UV detection at 230 nm. Figure courtesy of Chad Wissinger, Ohio University Click to enlarge image.

Many methods for the analysis of smokeless powders have appeared over the years. These procedures have been extensively reviewed in a number of recent texts (Beveridge 1998; National Research Council 1998; Yinon and Zitrin 1993). The initial characterization of the powders is assessed using powder morphology and spot tests. Various instrumental analytical techniques allow organic additives such as nitroglycerine, diphenylamine,
ethyl centralite, dinitrotoluene, and various phthalates to be detected and quantitated. These materials are usually analyzed using gas chromatography-mass spectrometry (Martz and Lasswell 1983) and liquid chromatography (Bender 1983; McCord and Bender 1998). Figure 3 illustrates the analysis of an IMR 700X powder using gradient high performance liquid chromatography (Wissinger and McCord 2002). More recently, methods involving capillary electrophoresis have also been shown to be effective (Northrop et al. 1991; Smith et al. 1999). Fourier transform infrared microscopy can be used for the identification of nitrocellulose (Zitrin 1998).
FIGURE 4: A line graph with 1 prominent downward spike.
Figure 4 IC Analysis of H414 smokeless powder by Hodgdon. Conditions Nucleosil Anion IIÒ Column, 1mM DCTA pH 5.2, 1.5 ml/min, UV detection at 205 nm. Click to enlarge image.

The process of manufacturing smokeless powders provides sources of inorganic ions that are present in postblast residue. These can be analyzed by ion chromatography. Although not unique to propellants, the presence of these ions can be used
in forensic analysis to aid in the identification of the unknown powder. Potassium sulfate, sodium sulfate, potassium nitrate, barium nitrate, and other salts
may be added during the processing of the powder. Nitrate, sulfate, hydrogen sulfide, chloride, and nitrite may appear as a result of the reactions for treating
the cellulose to obtain nitrocellulose (Radford Army Ammunition Plant 1987). Figure 4 illustrates the analysis of H414 smokeless powder using ion chromatography. Also documented has been the presence of various cations found in the residue of smokeless powders after deflagration (Hall and McCord 1993; Miyauchi et al. 1998).

Conclusions

The wide variety of chemical components and the different morphologies of smokeless powders present a challenge for the forensic investigator. Physical characteristics of partially burned and unburned powder as well as the organic and inorganic materials that remain must be considered in the analysis of postblast residue. Although there are many techniques available for the determination of components in smokeless powder residue, the various formulations of powders make it necessary to continue the advancement of existing analyses and to develop new methods for testing the full range of available smokeless powders.
 
I think that is the long way of saying the powder companies go to great lengths to get burn rates for cannister powder the same from lot to lot for cannister powders. If they did not, they could not safely sell the product, as we would have to work up load data with every lot. :eek:
 
I shoot a lot of AA#5--it's my go-to powder for 38/357 short barrel loads, and I like it in 45ACP as well, at least on the upper end. I've shot at least three different lots of it in the past two years--and I could not find any statistically-significant variation.

Jim H.
 
The photo in post #8 shows the Czech powder on the left. The company didnt screen the powder to ensure consistency.
Click to expand...
This Czech powder worked well enough I bought the one on the right :)
 
ccjcc81: It is a "messy" powder in the Lee Autodisk measures--it leaks by the actuating lever and dribbles out on to the turret, etc. I find that a bit bothersome.

OTOH, it meters accurately, and consistently. (I use only adjustable charge bars, however, and cannot speak to its use with the 'normal' Lee disks.) The drop variation is perhaps as little as plus-or-minus 0.05 gr. instead of plus-or-minus 0.1 gr.

Jim H.
 
I use A#5 alot in 40cal,155grn plated.Meters great in adjustable charge as noted by jfh.
 
It's Accurate's No. 7 and Alliant's Reloader 7 that are the two you don’t want to confuse.
657903.jpg
reloder_7_lg.jpg
 
That AA powder is some funky looking stuff. I tell ya.
 
ccjcc81: It is a "messy" powder in the Lee Autodisk measures--it leaks by the actuating lever and dribbles out on to the turret, etc. I find that a bit bothersome.

OTOH, it meters accurately, and consistently. (I use only adjustable charge bars, however, and cannot speak to its use with the 'normal' Lee disks.) The drop variation is perhaps as little as plus-or-minus 0.05 gr. instead of plus-or-minus 0.1 gr.
Click to expand...
I agree with Jim. I feel the results are worth the slight inconvenience AA#5 poses.
 
I've used it for .40 pushing 155 gr. LSWCs with descent accuracy. My problem came in cleaning my barrel (broach cut). I have never seen nor do I wish to again, so much fouling, bits of lead and unburnt powder. No other powder gave my measures (Dillon and Hornady with pistol metering inserts) as much trouble in 25 years of loading. I had to scale every load and though the Dillon never varied a single tenth the chargebar failed to return on most every load and required dissassembly and cleaning. (No, the powder was not wet).

I consider myself lucky to have all my fingers and pistol intact as the powder in question seems a common denominator for kabooms in nearly every Glock incident. Or maybe its just stray cosmic harmonics (are ATLAS particles to blame?) splitting plastic, you be the judge. As for me, I'm done with it.
 
The words polygonal rifling come to mind and the associated pressure it develops by sealing gas. Combined with the older less supported Glock chambers and some reloaders who don't know when to recycle their brass and it's quite possible the powder had little chance for success.

Still, some issues never do fully resolve themselves (think Ford Explorer and Firestone tires) and I'd rather not question my safety every time I squeeze the trigger.
 
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