"Downloaded ammunition"

[amc577]

We read a lot about the dangers of downloaded fullbore ammunition, as opposed to factory ammo, but examining a number of rimfire rounds...factory!..I find the case is less than half full in all types..does this mean that most rimfire ammo is "downloaded" ? Does the NSRA appreciate this....

amc577

[dodgyrog]

You need to clearly define the term 'downloaded ammunition' before entering into discussion about it!

[Turnup]

I believe that the NSRA are using the term "downloaded" to mean less than the powder manufacturer's starting load rather than simply a partially filled case.

You are correct, I have never come across a .22rf case more than about 1/3 full of powder.

Us pistol shooters have been downloading pistol ammunition for many years. The ubiquitous 2.7 grains of Bullseye in .38spl being a very common target load. The case is less than 1/4 full. I am presently using 2.9 grains of D032 (identical to Accurate #2) in .38spl for my Marlin.

Now I can't speak for rifle cartridges, but in my opinion the horror stories of "detonation" in downloaded pistol cartridges is just so much myth. If you think about it, adding a little more powder means that the deflagration process will initially pass through the conditions of the smaller charge on its way to greater things. There are dangers, but this comes from a light load leaving a bullet stuck in the barrel, and the unwary firing another one behind it. If a small charge can detonate, then so can a large one. Some of the "evidence" found on the interweb is clearly a misinterpretation of the results of detonation. A detonation is a chemical reaction which proceeds through the fuel supersonically, i.e. faster than the speed of sound in the powder itself. Since the powder is a solid this is very fast indeed. Such events will cause shattering. Claimed nitro detonations show no such evidence, barrels etc, being destroyed by stretching/deformations which are characteristic of over pressure.


If I were a member of the NSRA I would be demanding to see scientific evidence or citation of a reliable source to support these claims.

[dodgyrog]

Sad to say the NSRA board couldn't find their own backside let alone come to a considered and accurate definition of REDUCED VELOCITY ammunition - please note that the term downloaded is a complete misnomer!
If you want a reduced velocity rifle load I suggest you do the research that is available on the internet.
I load reduced velocity rifle loads using cast boolits and fast burning pistol powder if you want a starting point.

[Turnup]

According to the NSRA, "downloaded" of the dangerous kind is using less than the starting load as recommended by the powder manufacturer.

[amc577]

Never seen any recommendations for rimfire cartridges...presumably a "detonation" would be just as possible in a factory rimfire cartridge as in a home loaded cf cartridge. I would also imagine that many factory pistol calibre rounds are also"downloaded"...I am not entering into a discussion on "downloading", just pointing out that most of the ammo shot by NSRA smallbore shooters...is "downloaded" ammunition, in the sense that the cases are not fully charged.

amc577

[kennyc]

Never seen any recommendations for rimfire cartridges...presumably a "detonation" would be just as possible in a factory rimfire cartridge as in a home loaded cf cartridge. I would also imagine that many factory pistol calibre rounds are also"downloaded"...I am not entering into a discussion on "downloading", just pointing out that most of the ammo shot by NSRA smallbore shooters...is "downloaded" ammunition, in the sense that the cases are not fully charged.

amc577

do the cases have the powder manufacturers recommended amount of powder? if so they are not downloaded. if they held more they would be overloaded! case fill is no measure of downloading/overloading.

[amc577]

The "Stinger" ammo goes at 1600fps and the case is well filled..standard and subs ammo has very little powder and goes at 1040 fps and less....so....the standard long rifle cases are "downloaded" in order to reduce the muzzle velocity....which is just what the NSRA were complaining about with downloaded/ handloaded fullbore rounds

Wonder what maximum muzzle velocity is attainable with a full load of the correct powder in a long rifle case....the case is of course quite weak in order to allow ignition at the rim.

I have never seen any information on powder type or measure on any rimfire ammunition....at least the fullbore handloader knows what is in his cases...

amc577

[DesG]

The "Stinger" ammo goes at 1600fps and the case is well filled..standard and subs ammo has very little powder and goes at 1040 fps and less....so....the standard long rifle cases are "downloaded" in order to reduce the muzzle velocity....which is just what the NSRA were complaining about with downloaded/ handloaded fullbore rounds

Wonder what maximum muzzle velocity is attainable with a full load of the correct powder in a long rifle case....the case is of course quite weak in order to allow ignition at the rim.

I have never seen any information on powder type or measure on any rimfire ammunition....at least the fullbore handloader knows what is in his cases...

amc577

You could always make the case a little longer to get more velocity. Strange no-one's ever thought of it!

[Daryll]

They should change the wording to "under charged"... most gallery rifle shooters make low velocity, low recoil ammo for competition use, so "down loaded" from normal commercial loads, but these are still published loads.

"under charged" would mean below recommended published loads.

[sarge4318]

in the powder itself.[/I] Since the powder is a solid this is very fast indeed. Such events will cause shattering. Claimed nitro detonations show no such evidence, barrels etc, being destroyed by stretching/deformations which are characteristic of over pressure.

I have seen first hand the effects of downloaded detonations of rifle ammunition three times.

First was someone reducing the loading to try and get a subsonic load but managed to get a detonation first. We heard the bang in a cubicle along the range and saw the shooter trying to hammer the gun open. It held together but the brass flowed and jammed the bolt.

Second and third were light charges due to poor powder measures (one it was found had a small piece of the powder tub sealant stuck in the powder hopper, I never found out the reason for the other light charge).
In one instance the case ruptured and destroyed the bolt, bolt carrier and magazine of the rifle, most of the recovered rounds were found to be approximately 50% the intended charge. We didn't find all the magazine parts.
The final one the brass again flowed around the bolt but didn't fail at any part other than the primer. No visual damage to the rifle.

In all the cases the worst injury was a stinging hand where the shooter was resting the rifle magazine on his gloved palm.

[Turnup]

I have seen first hand the effects of downloaded detonations of rifle ammunition three times.

First was someone reducing the loading to try and get a subsonic load but managed to get a detonation first. We heard the bang in a cubicle along the range and saw the shooter trying to hammer the gun open. It held together but the brass flowed and jammed the bolt.

Second and third were light charges due to poor powder measures (one it was found had a small piece of the powder tub sealant stuck in the powder hopper, I never found out the reason for the other light charge).
In one instance the case ruptured and destroyed the bolt, bolt carrier and magazine of the rifle, most of the recovered rounds were found to be approximately 50% the intended charge. We didn't find all the magazine parts.
The final one the brass again flowed around the bolt but didn't fail at any part other than the primer. No visual damage to the rifle.

In all the cases the worst injury was a stinging hand where the shooter was resting the rifle magazine on his gloved palm.

Glad to hear no injuries. Scary stuff.

Possibly splitting hairs but not evidence of detonation, however clearly overpressure events.

Interesting:

Rifle or pistol cases?

Absolutely certain that there were not overpressure from a stuck bullet (light charge failing to eject the preceding bullet)?

It is possible for the second bullet to eject them both so there is nothing remaining in the barrel. I have seen this with a factory .22rf - no sign of any bullet or part of a bullet in the barrel, but there was a ring bulge a couple of inches back from the muzzle and no other damage - the shooter had not noticed anything unusual while firing (experienced shooter) but two too few holes in the target, a good group, to his usual standard, and three fliers, from which we concluded that shot 6 had remained in the barrel, shot 7 caused the ring bulge and ejected bullet 6 and itself, and the three fliers were shot through the ensuing ring bulge. So this was an overpressure event caused by barrel obstruction and certainly not a detonation.

The reason I am dubious is that the damage you report in two of the events is not consistent with detonation, which would cause either shattering fractures (clean fractures and little or no sign of distortion) or no failures if insufficient pressure developed. Distortions evidenced by stretching and/or bending result from overpressure but not detonation. With a detonation there is simply not time for the metal to flow and bend, it either shatters or resists the pressure and is unaffected.

The one event where the gun came apart - were the fracture edges clean or ragged and were there signs of bending/stretching type distortions at the fracture sites?

[sarge4318]

All of the three were .223Rem reloads, the first in a bolt gun, make I know not, and the last two were straight pull AR types.

Detonation is probably the wrong term, but secondary explosion effect might be more suitable. Whatever term used the effect is a pressure spike causing something to fail and in these three firearms the cartridge case was the weakest link (after the ammo loader of course ).

[MikB]

Of course .22lr cases are only partially full - they were originally for black powder, where a compressed case full was only just enough to match what would now be regarded as a mild load.

I did see results of a 'detonation' many years ago. A 38 Special revolver cylinder had been stretched uniformly along a longitudinal line where the wall was thinnest, binding rotation past the cylinder bolt at that point. The owner recovered it by compressing the cylinder back to size in a pair of bored vice jaws, and continued to use the gun for years afterwards - though I don't know if he omitted the re - squeezed chamber, or even if he knew which one it was... ��

Nobel No.3 pistol powder was blamed - a very fast powder which rightly or wrongly had a bad rep in light loads.

[tacfoley]

I bleeve that the term 'downloading' refers to the use of other propellants than those usually recommended being used for low[er] velocity shooting - usually of cast lead bullets rather than the jacketed bullets normally shot in that particular calibre.

The use of the correct propellants is termed a 'reduced load' as it is the correct propellant, but less of it.

The instructions in MOST loading manuals are totally clear, and leave no room for interpretation 'IT IS DANGEROUS TO REDUCE THE LOAD TO LESS THAN THE RECOMMENDED FIGURE'.

What is so hard about that?

tac