How much PSI could cause this?

[Blue Avenger]

What is the Cause of SEE. Its almost self explanitory but Im more complex than that. ???


When you have too little case fill to cover the primer the powder can be ignited in multiple spots. When the pressure waves hit you get a pressure spike. Which is why people use fillers, whether cream of wheat or cotton, to hold the powder against the primer.
with to much air in the case, THE POWDER ACTUALLY EXPLODES INSIDE THE CASE, RATHER THEN A CONTROLLED EXPANSION.

Why some of use cringe when you talk reduced loads with other then proven powders!

[Eric in NC]

I had discounted SEE as a possibility because 1) 221 is such a small case and 2) Blue Dot is a pretty fast powder. Seen it happen with things like 45-70, and in particular the big magnums, but never heard of it in a very small case like the 221. I did see where ATK says not to use Blue Dot in light bullet 357 loads now - and the 357 and 221 are roughly the same size and the 221 bullet is MUCH lighter so I guess it is even a known problem.

I just sidestep the issue by using 4759, 4198, 5744 etc. in cast bullet loads.

[ellobo]

I think there is a misinterpretation of SEE. Modern powders to not explode, they burn at a phenominaly high rate. The explosion of the SEE kind is a result of the pressure spikes due to the uneven burning of the powder but not of the powder "exploding".

El Lobo

[wbm]

If it were me, I would pay extremely close attention to the words of Blue Avenger and Sharpshooter and give up shooting those cast "boolits".

[sharpshooter]

Secondary explosion effect would imply that there is a primary explosion. The word "explosion" is a misnomer... there are no explosions, only higher than normal or expected pressures.
One of the leading causes in a reduced load causing pressure is the fact the case is not to full case density. A fluffy powder such as any flake type double base powder takes up little space in a rifle case. When the primer is detonated, it has such a blast wave it blows the powder about without instantaneous ignition and at the same time it has enough pressure to unseat the bullet from the case, moving it forward with just enough energy to wedge it into the throat. This act just like an obstructed bore. When the powder finally gets to full pressure, it hits a bullet that is now partially obturated and increased in resistance.
In simple terms; this is like being rear ended in your car. If both vehicles were stopped and you mated bumpers and then proceeded to push the car ahead, you're fine. If you hit car ahead with a running start, well you know what I mean.

[stangfish]

Thanks for elaborating gentlemen. That info might save my or someone elses extremities or life on day.

[ellobo]

There is nothing wrong with shooting cast bullets if you use your head for something besides a hatrack.. I have fired hndreds if not thousands of cast bulllets from a .308 using proper powders and min loading data from the manuals. I hard cast the bullets (using linotype metal or solder in the lead) lube and size them with gas checks. I have never had a problem with leading but then again I wasnt using a Savage with a rough barrel so with a Savage act accordingly. I never saw a sign of high pressure and some powders gave phenomonal accuracy out of My Winchester Model 70. Light recoil is good for kids and ladies as they are cheap and you can get a lot of practice for little money. By the way. The most accurate bullets I have cast came from wheel wgts that most garages will give you free.

El Lobo

[RustyW]

Here's a link if you want to read some more disscusion about SEE. http://castboolits.gunloads.com/showthread.php?t=138177
I don't blame the cast bullets for the bad experiance. I've been shooting cast for way to many years to blame them. It's a combination that didn't work out. I don't blame the powder either, it just wasn't the correct choice for this application & luckily I came out unscathed. I've been handloading for nearly 28 years, casting my own bullets for the last 5/6 years. Shot thousands of rounds both reduced & full power loads and have never had this sort of thing happen. I've never used Blue Dot in anything other than 44mag either. Trailboss, Unique, & 2400 is what I've always used for reduced/cast loads in rifle's and all has been good. One thing I have learned is Blue Dot & reduced loads don't go well together.

[teebirdhyzer]

I have read about SEE, but never seen anything like that. Very glad you are OK!

[Jamie]

That "phenominaly high rate" is actually an explosion. The rate of the burn/expansion determines if it is a low explosive or high explosive.

[airaddict]

This is all very interesting cuz ive never heard of SEE at all but i have never loaded cast for rifle....yet. Only handgun. Gives me lots to consider when i do decide to tiptoe into it.

Brian

[Jamie]

This is all very interesting cuz ive never heard of SEE at all but i have never loaded cast for rifle....yet. Only handgun. Gives me lots to consider when i do decide to tiptoe into it.

Brian


Use proper powder your setup and follow the books and you will be fine.

[hound53]

never used any blue dot but that sure looks like more than 8 grains in the picture of the pan. Might just be the camera angle. Anyway glad you are ok, I double charged a .45 ACP a while back, other than cracking a grip , damaging the magazine and ruining a good pair of boxer shorts I was ok but the incident made me come off the wallet to buy a powder cop die for my progressive.

[skoger]

I have read of/seen this same thing happeniing a lot with the 25/06 and light loads in several other calibers, using jacketed bullets in articles and books by PO Ackley. What happens , he thought, is that the gas/fumes present with any type of smokeless powder ignites first, and the powder in these light loads that is lying underneath ingites secondary when the primer is fired. The ignition of the powder gasses pushes the bullet into the bore so far, then the powder ignites/detonates and the bullet acts like a plug in your barrel or obstruction like mud or debri. A buddy of mine, a 25/06 lover did not believe this, and tried it in his 98 mauser 25/06, custom job, and warped the action, cracked the lugs, had to drive the bolt handle open with a hammer,completley wrecked the rifle. PO stated that the 25/06 was worst caliber for this to happen. Just chiming in, makes sense to me though.