Secondary Explosion Effect

[Lane]

Last night in the chat box, Dave Waits was once again trying to help me keep all my body parts intact and functioning as normal. Need another holster yet, Dave?

Anyway, we were discussing loads and what works - and Dave tossed out the term "detonation." That got me thinking (which is usually a scary thing) and I started looking for more info. Many people refer to it as Secondary Explosion Effect (SEE) - but I tend to think this is inaccurate.

The theory is that if a load is "too" light, you can create a situation where the power detonates instead of burning, resulting in an exploded barrel, missing body parts, etc.

The problem, from what I've been able to find so far, is that no one is certain what causes this. It can't be reproduced in a lab. In fact there are some that believe it's not a chemical problem, but a problem that with a small load, it's easier to double charge a case.

I've seen "definitive" statements that it's only light charges with fast burning powder, and other that it's only slow burning powder. There's also a pretty good contingent that believe more in the user error side of things vs actual chemical problems (probably due to the fact that it can't be duplicated in the lab.)

It was even bandied about as a topic for Myth Busters.

I sent an email to Alliant customer support to see if they had any addition information or recommendations. I'll pass along anything they send.

Without a doubt, it is an interesting topic.

Lane

[Big Smoke]

Much like how a gas tank is more explosive with a little bit of gas rather than a full tank (which is the vapors that cause the explosion), one theory is that of oxygen content in the case (fast burning powder mixed with too much oxygen in a contained space). I don't know if this have any validity, but the theory sounds plausible to me.
That's why there are minimum loads, and maximum loads.

[Dave Waits]

'Detonation' is real and it started in the Bullseye Fraternity. Using, of course, Bullseye powder, which is an extremely fast-burning powder. Problem was, a charge of this powder,enough to propel a .45ACP,185gr.SWC to 740fps, wouldn't cover the entire inside bottom of the case. Plus, the swift pressure-build of the charge was so fast and large it detonated the case(Actually, it would blow the rim back against the breechface, flow the primer back into the firing-pin hole and rupture the case right above the rim). Remember, 3.1 grains of Bullseye will, with a 148 gr.HBFWC, attain 800fps in a 38Spl!
Bullseye is a lot like 296, you have to follow the manual exactly and not deviate at all. No manual I know of lists Bullseye anymore for the 45ACP either.

[Lane]

Originally Posted by Dave Waits

'Detonation' is real

I don't doubt that for a second. That's why I spent an hour yesterday pulling bullets. I'm not going to mess with it. I guess the point of my original post was that there is so much mis-information or conflicting information.

I guess the thing that really got me wondering was seeing the chart on burn rates that you posted a few days back. I've been using Clays for .45ACP for quite a while. Clays was quite high in the list as far as burn rate (#10 if I remember right). The load I've been using (based on a reloading manual I have) is 3.7gr. This load leaves a lot of empty space in the case.

I've loaded and shot literally thousands of rounds with no issues - but I'm wondering if I'm spinning the roulette wheel.

Dave, one again, your experience and knowledge is greatly appreciated.

BTW - do you happen to have a compact 1911? I was cutting leather for my new RIA last night, and inadvertently flipped the patterns. So, I've got the pieces for a lefty.

Lane

[DaFadda]

To Lane's comment: "using Clays for .45ACP for quite a while. Clays was quite high in the list as far as burn rate (#10 if I remember right). The load I've been using (based on a reloading manual I have) is 3.7gr."

I use loads from Speer #14 Reloading manual. Page 972 for Gold Dot Hollow Point in 230 grains: 5.5 gr H. Universal is the minimum load. Max is 6.3. Bullseye is also listed with a min. of 4.5 gr to 5.0 gr. Theoretically... the smaller the bullet grain, the more powder is used. (i.e. a 185 gr bullet has a min of 6.9 instead of 5.5 H Universal with a 230gr bullet)

Looked at the bottle of H. Universal Clays that I have and it says the MAX load for .45 is 6.4, and to reduce by 10% to start. So that would be 5.76 gr to start.

I would be concerned if you are using Clays at 3.7. I'm hoping that the above 3.7 is a mistype.

As someone above says (I think it was Dave) Do not deviate from the minimums and maximums. That said, I've been happy with Bullseye for several years. Its been being put into .45's since 1913. I load 4.7 grains bullseye under a Montana Gold 230 grain JHP for target. Its been a good, low recoil, accurate load for me. But below 4.5? Not in my gun. H. Universal Clays has been just as good to me.

Just my 2 cents, Hope it helps and adds to the confusion (oops, meant Conversation!)

[DaFadda]

OK... Lane and I have compared notes. He is using Hodgden's Clay powder. I use Hodgden UNIVERSAL CLays. There IS a difference. Took a bit of discussion on IM to figure it out. The IM feature on this board is a great addition!!!!

Da

[Lane]

Originally Posted by DaFadda

OK... Lane and I have compared notes. He is using Hodgden's Clay powder. I use Hodgden UNIVERSAL CLays. There IS a difference. Took a bit of discussion on IM to figure it out. The IM feature on this board is a great addition!!!!

Da

Agreed.

And, I appreciate the friendship here. The fact that the gang here care enough about my safety to help me not make a mistake (quite honestly, I can't believe God hasn't let me kill myself before now... )

Anyway, Dave - thank you again for your vast knowledge and understanding - and Michael - thanks for the chat this morning. I feel much better about what I'm doing and what I won't be doing.

Lane