Originally Posted by tmitch
I just read a match banned over powder wads for loads using smokeless powder due to the prevelence of pressure issues using that method. Trying to find where I read it so I can link it.


**Found it.............The Matthew Quigley match. I copied and pasted their explanatiion below:

Safety Issues of Concern

Note: This is not a directive on how to reload. It is a note of caution and a warning about some of the dangers. If you reload for yourself or others, you do so at your own risk.

The last few years it has become increasingly clear that certain reloading practices are increasing the dangers inherent is our sport of rifle shooting. We will try to outline some of these practices and dangers so you are made aware of them. Not all of these are fully understood since the science is a difficult one to observe and the effects are likely variable due to even minute changes in the causing condition, equipment and other parts of the equation.

Three basic types of powder are used in our sport although they are often listed as two (black powder and smokeless). These basic types are more directly labeled as black powder (and substitute), single-base smokeless (nitrocellulose) and double base smokeless (which has an added buffered nitroglycerine component).

The primary problem we have been experiencing has been unexpected loss of control of the propellant combustion.

Powder manufacturers have experimented greatly in this regard and, with loaded ammunition provided by them, have maintained a cautious approach with a generous (though not large) margin for safety. They, by demand, also supply reloading supplies to their customers and by various means have supplied safety guidelines for the use of their product. This is where we come into the picture. We reload because the volume of our shooting demands cost savings.

The problem is showing up as damaged firearms and some explosions that can injure and/or kill people. There is always an inherent danger in our sport, but the practices of some are making it more so.
A number of rifles have emerged with the dreaded chamber ring. This is often first noticed as sticking cases and, when inspecting the cases, a noticeable, protruding ring is found around the case approximately where the base of the bullet would be inside the case. Carrying this inspection further shows a ring in the wall of the chamber at this point. This chamber ring is an indication of being close to the pressures that will burst the gun.

So far, virtually all of these known instances have been with the use of double-based powder and usually (admittedly) using a wad in the case that held the powder back against the primer. These are usually lighter loads in large cases.

The facts are that the manufacturers have sold this powder carefully marked as double-based and have made efforts to inform the user not to use an over-powder wad with it (card wad, cotton wad, polyester fiber wad or other types). Some have cautioned not to use reduced charges (below a recommended minimum charge).

The use of a wad over the powder provides an air space between the ignited powder and the base of the bullet. The powder is ignited and burns from behind, pushing the unburned powder in front of the burn. The unburned powder gains momentum and gathers heat. The air is compressed but the bullet remains stationary. Then, the unburned powder slams into the base of the bullet. The powder is sensitive to temperature and impact. At this point, both are provided and a new rate of burn and energy release comes into play. It’s best thought of as a new, highly volatile explosion, usually called detonation, of the unburned powder.

The manufacturer has carefully tested the powder in single-cavity chambers and has provided guidelines for such use, but the separated cavity with the wad and associated airspace hasn’t been (and presently can’t be) fully accounted for. The pressures generated will displace solid steel by extrusion, shear or rupture depending on the strength of the steel and the pressure generated by the exploding force. Small increases in powder charge or resistance to the movement of the bullet can be the difference.
The difference between a chamber ring and a burst barrel may be only a couple of grains of the unburned powder before the detonation. Double-based powder is very useful without the wad. With an over-powder wad, it’s a dangerous commodity – the air gap being the problem and not the wad itself. Air compresses a long way before much pressure is generated. A case full of air compressed down to almost nothing won’t move a bullet.

It should be noted that a wad isn’t needed to supply the air gap. Simply pointing a lightly loaded rifle straight up (providing a volume of air space between the powder and the bullet without a wad) will do that and, therefore, a rifle loaded with a chamber-ringing below load data level of powder will ring the chamber without the presence of a wad.

All gun powders are temperature and percussion-sensitive but single-based powder (nitrocellulose) is much less sensitive than double-based powders and within reason can be controlled.
The use of a wad and air gap with single-based powders is much less apt to damage or destroy a firearm than with double-based powders, but it can be done with improper load data and careless reloading procedures.

Black powder is also very sensitive to heat and percussion and does cause this phenomenon of sudden increase in pressure in the presence of an air gap, but in equal quantities develops much less pressure than either type of smokeless powder. However, too much of any gunpowder will blow up and destroy a firearm.

The air gap phenomenon described above does occur with black powder, although with a relatively milder detonation. With certain loads it can blow up a gun and has done so in the past. The use of a small quantity of smokeless powder or finer grade of black powder (4Fg or dust) to ignite a normal load of black powder will cause the coarser powder to burn with a greater intensity and pressure and present the danger of burst rifles. An included air gap will also add to the pressure – sometimes greatly so.

An overcharge of any powder can blow up a gun and many things can and do cause pressure increases. Some of these are: heavier bullets, longer bullets, bullets engraved into the rifling, harder bullets, dirty bullets, bullets with inclusions, obstructions in the bore (even soft things like mud or a bug, sometimes even water), hotter primers, cases too long for the chamber and wrong powder. Since some shooters are pushing the envelope of pressure already, any of the aforementioned items can push the pressures beyond what can be contained, and an unexpected, uncontrolled explosion will result.
Another consideration is the strength of the steel of the barrel and the rifle action. Modern steels are in general much stronger than antique steels, but some modern steels are stronger than others. Be aware of the strength of your rifle.

Be safe and stay within known guidelines. We want you all to enjoy the sport of shooting for many years to come.

Interesting, thanks for that. I didn't see reference in particular of the ringing issue to the use of reduced loads using fast burning powders ie pistol powders. There's plenty of cases where ringing isn't an issue with reduced loads using fast rifle powders with spaces and/or fillers. The only ringing issues I've heard of were reduced loads with pistol powders in straight wall cases with or without wads.

Graeme Wright wrote a little bit about it also in his "Shooting the British Double Rifle" - I'll have to reread it.

Originally Posted by mauserand9mm
Originally Posted by mauserand9mm
Originally Posted by Raspy
Whatever you said...everyone knows you are a lying jerk.

That's a bold assertion. Point out where you think I lied.

Well?