What are the dangers of loading well below minimum? I know of a guy that loaded a bunch of 223 Rem with 55gr Speer bullets and 21.9gr of Varget. Speer and Lyman list 25gr starting load and Sierra list 25.5gr starting load. What kind of bad things if any can happen shooting this load?

My understanding, Steve, is that this can be dangerous.

Especially dangerous when using slow burning powders, which are prone to pressure spikes.

flaco

Loadtech calls that load below 40,000psi. I wouldn't go that far below minimum but I have no proof that it would be dangerous. Each powder, case, bullet combo will act different to being 15% below min.

This is interesting. My load reference, Metallic Cartridge Reloading, 3rd Edition does not list a minimum or starting load for a 55gr bullet and Varget powder. It also says that the .223 Remington case has a useful case capacity of 28.8 gr. Perhaps 21.9 grains of Varget fills the case sufficiently that no detrimental pressure waves arise.

Did your guy actually fire these reduced loads? Does he use the thicker military cases? MCR doesn't mention any cautions for low pressure loads, but it does list one:

quote:

Using full listed loads in military cases can result in dangerous pressures.

Might be an accurate FMJ load for fall wild turkeys where you want to pencil right through and not ruin tasty breast meat?

quote:

Originally posted by ramrod340:
Loadtech calls that load below 40,000psi. I wouldn't go that far below minimum but I have no proof that it would be dangerous. Each powder, case, bullet combo will act different to being 15% below min.

Very well stated.....it has long been said that overly reduced loads (whatever that is) of especially slow (whatever that is) burning powders can be dangerous......and this just might be true.....or it could be merely internet bullpucky!

I've never wanted to load that low to find out.....and while I thuly don't believe it.....there has not in my eyes been proof....nor do I want to be the one to furnish it!

vapo-

It may in fact be bullpucky, but it's not limited to the internet.

My source is the 7th Hornady Handbook.

flaco

Powders vary in ease of ignition.
If you will note in Winchester ball powder data some of it specifically forbids using loads lower than the manual lists. This was with 296 in the 44 Magnum.
I can give you a reduced load combination for an extruded powder that might get you a blown primer. The powder has been sold as a competitor to 4895.

However 4895 has been recommended for significantly reduced loads for decades and I have yet to hear of a reduced load accident with it. I think the reduced load warnings have to be considered in view of how hard the powder is to ignite. I suspect it is more a problem with ball/spherical powders.

First of all I do not claim to be an expert, but testing powders as I do there are things you learn.

When reducing powder charges of slow burning powders you reach a point where the temperature and the pressure are not adequate to achieve complete burning and you blow unburned powder out the barrel.

To me something says ,Hey go to a more appropriate faster burning powder.

In my world it is more inteligent to go to faster burnig powders as your velocity goal is reducing, Ergo the now famous Blue Dot scenario and beyond. roger.

Roger
I agree with you statement. When I see a lot of unburned powder left in the bore I prefer to switch propellants.
First I don't think it is burning at the pressure it is designed and is probably not producing uniform velocities.
Second you often get a lot of soot around the case because the case does not expand and seal due to the low pressure.
Third I don't like running over large amounts of unburned powder with a bullet. It can't be that good for the bullet or the barrel.

One thing I have learned is the barrel length also affects how complete the burn is.
I shoot a few old Mausers and I don't like to load them heavily. A load that leaves unburned powder in a carbine barrel may burn completely in a 29" barrel.