So…Pulling down some hand loads that were from a development effort back on 06 - 07.
This was ammo for short range rapids in XC shooting. National Match stuff.
Everything was identical except for 2 powder types.
Berger 73gr LTB bullets
New Federal Gold Medal .223 brass - factory primed w/ FGM 205M primers.
Powder was various weights of N140 and N540. All slightly compressed
Pulled all the bullets w/ a Hornady LNL collet puller - the 140 loads came out a bit sticky - took a tad more oomph to get them out.
540 loads came out with ease. I noticed in all the 140 loads, the base of bullet was discolored. The 540 loads - base of the bullet looked brand new.
Here is the kicker; The 540 loads pour out after a little help with a toothpick - easy. Inside the cases - clean and bright - new brass just like when they were loaded.
The 140 loads…wow! Inside the cases were almost black. The powder had to be scraped off the walls and the walls were what appeared to be oxidized. Kind of a greenish grey discoloration.
I have never ever seen anything like this - anyone ever experience anything similar?
Theories?
Hunches?
I use n135 and n140 and have never experienced this myself. Would be interesting to know what chemical reaction causes this and if there is a time frame/shelf life for VV loads.
Good find - I read through the whole thread. It is interesting to note that this ammo was loaded in brand new Fed GM brass w/ factory loaded FGM 205 M primers - both powders were dropped during the same loading session. Brass came from the same box - literally everything was exactly the same except the powder types. The two different powder type / loaded ammo were stored in the same MTM plastic box. My shop is temp / humidity controlled - the only difference between the corroded ammo and the non corroded was x number had N140 and x number had N540. Really is very strange.
Interestingly enough, I never had much luck with the N140. Far better results w/ N540.
I will dump the pull down powder in the garden (my wife thinks she has a green thumb - little does she know how much old powder goes in the flower beds LOL) :lol:
Sticking with N540 for a new effort.
Would love to get to the bottom of this though.
I believe there are some significant differences in the chemistry of VV N140 and N540, 140 being a single base (nitrocellulose) propellant and 540 being double-based (nitrocellulose and nitroglycerin – higher velocity at less pressure but higher temperature).
Smokeless powder manufacturers will add different stuff which affects powder in different ways. Each can affect how the powder deteriorates.
Deterrants affect burn rate. Stabilizers reduce decomposition and oxidation. Flash reducers come at the cost of added smoke. Other ingredients help in reducing powder or copper fouling, reducing barrel wear, aid production by keeping propellant grains round, reducing clumping, helping powder grains flow through machinery, or by helping to reduce static electricity and sparking.
If you leave powder in a powder measure with a clear plastic storage tube you may notice the transparency and color of the plastic changing over time as it’s affected by chemical exposure or change. This may be from acids or other chemical interaction with the plastic.
Here is a pic of a sectioned case - which was loaded with N140. Every case was like this as well as the bullet bases (see the ones on the right). The cases loaded w/ N540 were spotless - I didn’t even bother sectioning them. The bullets were fine as well. Again - this was a development effort - the brass came from the same lot, was prepped all at the same time, loaded within minutes of one another - bullets from the same box.
The only variable was the powder. This was loaded in 2007.
I’d love to get Vihtavouri’s take on it, but I highly doubt they’d even comment on it.
BTW - all ammo is stored in GI cans, with desiccant bags. Shop is climate controlled as well.
Baffled here…
Anyone want to buy some N140? 24lbs available…:blink:
Nitrocellulose smokeless powder begins to deteriorate as soon as it’s produced. Diphenylamine is usually added at 2 percent by weight to help slow the oxidation process.
Army Quality Assurance Specialist Ammunition Surveillance folks monitor ammo for heat and decomposition. Once ammo gets old, stale, or acid (by measuring fumes and heat) they’ll test ammo by lots (including sealed ammo). Some stuff like .50 cal, .45 ACP, 30-06, and 105mm howitzer ammo produced during WWII and Korea is still serviceable and soldiering on.
Some stuff gets to a certain identified safety level or level of decomposition and gets pulled down. Components might be sold as pulled powder, brass, and bullets, while the primers are chemically inerted (usually by immersing in an oil).
Interesting to note the N140 seems to have a fairly aggressive corrosion rate in this particular case.
A spin-off the Army found with its WWI 30-06 was tin-plated bullet jackets cold-soldering to the inside of case necks. Hatcher explained this would boost pressures to near-proof levels.
it would be interesting to find out whether the n140 you had issues with is the same lot# as the person at falfiles, perhaps it was more something to do with that lot of powder than n140 in general. that said, in my experience VV powder is generally very consistent lot to lot and it seems that there is a 3-4 year gap between the falfiles poster loadings and yours opsoff so the chances of this are likely very low.
I am curious too - I joined Falfiles so I could contact him - definitely wanted to compare lot #'s. I have always had pretty good luck with VV powders, until they got so expensive. Luckily I’m sitting on a lot (other than the N140)
Finding really good results with 73 Bergers and N540 right now.
Also - N140 is a single base powder - the 5 series are double base. I know that single base powders are hygroscopic - so maybe on some weird outside chance, there was some moisture in that powder. If not - it has to be some type of chemical reaction.
I am finding it hard to believe that it was moisture though - I have probably 20+ different powders on hand, some of which are 15 - 20 yrs old - still use them occasionally - never an issue with any of the others new or old and they are all stored in the same place right next to each other.
agree with the thoughts on it likely not being moisture, i too have some powder that has been around for a long time (I have about two pounds of the original Thunderbird, no it is not for sale ) and it is all fine/useable, in fact I am still using varget from the same 8 lb keg my grandfather gave me when he started teaching me to handload (14 years ago). hopefully you are able to find a cause for the degredation of the ammo using n140.
Did you tumble the brass before loading it? Is it possible that lubricant used during the brass forming process interacted chemically with the N140? Do you think the chemicals used to effect the hygroscopic properties of the powder interacted with the brass?
One manufacturing process uses organic solvents and another process uses water. The water or solvents must be dried before packaging the powder. Could it be that the batch of N140 powder you used was not dried enough after the manufacture process and prior to packaging at the factory?
Getting a manufacturer to reveal the chemicals used in their powder making process may be an exercise in futility.
T2C,
Good questions - the brass was new Federal Gold Medal - factory primed w/ 205M’s - right out of the carton. The only things that were done: neck size with a TiN bushing, so no lube involved or tumbling or really any other operation. The interesting or perplexing point is all the brass came out of the same box, was processed at the same time, loaded with bullets out of the same box. The only variable was half the brass got N140 and half got N540. I also have some ammo development / tests using the same components (loaded at a different session) using N135 - no issues with that either. Appears to be specific to N140.
I’ll definitely keep on this as I want to find out the root cause. The big question is this a byproduct of too long in storage - so if I load and shoot N140 now it’ll be ok or is it an issue where the powder has gone bad?
This is an extract from the FBI (Forensic Science Communications, April 2002 - Volume 4 - Number 2, 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
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.
It sounds like this particular lot of N140 might not have been properly manufactured.
) and it is all fine/useable, in fact I am still using varget from the same 8 lb keg my grandfather gave me when he started teaching me to handload (14 years ago). hopefully you are able to find a cause for the degredation of the ammo using n140.