case explosion

[Lost Sheep]

Clay's

International Clays (or is this not ever used for handguns?)

Universal Clays

Lost Sheep

[Hammerhead]

I use Universal more than any other powder, but Hodgdon has a very poor naming system with the Clays powder. They have improved it some by labeling the cans more clearly now.

SR-4756 and SR-4759 are a little close in name as well.

[Edward429451]

Reloading is something that you need to follow to the letter.

While this sounds good on paper, it is not necessarily true with handgun cartridge loading, or even rifle Cartridges actually. It is very true when loading for shotgun shells.

It is almost impossible to follow a load recipe to the letter. Having every single component exactly the same would mean stocking way more than is reasonably possible. The only critical thing to have exact is the gun powder. Substitution of primers is the norm, substitution of bullets is very common. You want to use common sense (Uh-oh). The bullet weight should be the same in the data. You want to understand that substituting a Mag primer when it call for a standard can easily increase pressures by ~2000 psi.

I am in my 4th decade of reloading and have made so many substitutions that I can not remember them all. I've never went KB. I've made plenty of extrapolations with no ill effects. It is in fact the norm to do so.

The biggest mistake that I see people commonly make (is not using common sense) is to not read the details and keep in mind that they are making substitutions so they....(wait for it)...fail to use the STARTING LOADS. When you make a substitution, it's fairly critical to understand that substitutions could give you excess pressure.

Most people are impatient and so they take the max load, reduce by 10 or 15% and start there. Because they heard it from an internet expert that, that's the thing to do. This is wrong. The time to do that is when you have an established load and you are very familiar with it, and you get a new batch of powder or primers. Then you reduce by 15% and work the load up again.

This business of starting max reduced is insanity. but that's the load that joey uses and it works fine in his gun. Fine. That's Joeys gun. Manufacturing tolerances vary even between different guns of the same model. Using that load in an XX gun when you have a YY gun is equally insane. This is what starting loads are for. If you must be anal about something, be anal about using starting loads. Even if you have the EXACT components used in the recipe, you should still use starting loads. You don't have a pressure test barrel. You don't have the same gun they used for testing. This information is in your load book if you care enough to read the darn thing.

Why do you guys think the starting loads are there for? Are they for the wussies? Oh, but your a mans man. Do you think that they can tell at the range when you shoot that it's a starting load, and perhaps they'll laugh at you? Don't be so impatient to get to max loads. Follow reloading procedure to the letter and begin with the start load, and work it up in your gun. Don't be so impatient to load up 1000 rounds of it. Load 5 or 10 rounds of it and try them. Then if it's no good, you wont have to pull so many. If it's ok but too weak for your purpose, you wont have much to shoot up. I've been loading so long and have so much experience that I sometimes go whole hog and load up (gasp!) 20 rounds. Depends what it is and how familiar I am with that powder. Previously unused by me? 5 or 10 rounds.

[Edward429451]

Lead would be a lower starting and maximum load

This is generally incorrect. Lead has less friction than copper so takes more powder than it's jacketed counterpart to get it up to speed. More friction from the copper means it sits still in the case longer, raising pressures more before it starts moving. Copper takes less powder than lead for equivalent speeds.

[ScottRiqui]

Lead has less friction than copper so takes more powder than it's jacketed counterpart to get it up to speed. More friction from the copper means it sits still in the case longer, raising pressures more before it starts moving. Copper takes less powder than lead for equivalent speeds.

I like that explanation a lot. In a sense, the extra friction from a copper-jacketed bullet mimics the effects of a heavier bullet (more resistance to being propelled forward).

[dacaur]

Lead would be a lower starting and maximum load

This is generally incorrect. Lead has less friction than copper so takes more powder than it's jacketed counterpart to get it up to speed. More friction from the copper means it sits still in the case longer, raising pressures more before it starts moving. Copper takes less powder than lead for equivalent speeds.

Not quite. you are both somewhat right, and wrong...

In a semi auto Edward429451 is partly correct, assuming the same powder, the starting and max loads are generally pretty close, so long as the copper speeds are not too fast since i think the general consensus is to keep lead below 1000fps to avoid leading. The last statement though "Copper takes less powder than lead for equivalent speeds." is incorrect, from what I can see, they are always pretty close, in a semi auto, Sometimes copper will take a minute amount more, sometimes lead.

but in a revolver, m&p45acp10+1 is correct that the starting and max loads for lead are almost always significantly lower, but both still achieve the same speeds.

Why? Its all about the gap. In a semi auto, the copper bullet has the benefit of the combustion gasses pushing on it all the way to the muzzle, It gets the same speed as the lead, because even though (or perhaps because) lead is easier to push, the increased friction from the copper means higher pressures. But in a revolver you get that first initial push and that's it, then the increased friction from copper comes into play, slowing it down all the way out of the barrel, which means that first initial push has to be bigger to get the same speed.

[Edward429451]

You make it sound feasible, but have you checked your load manuals to see if they support your theory?

Edited to add, I see it goes both ways in the manual. with different loadings and powders. I must just be used to certain loads which support my theory. I stand partially corrected!

[dacaur]

I stand partially corrected!

I literally LOL'd at that... wife thinks I'm crazy, thanks.

[shootniron]

It wasn't your primers. Blaming them is going to lead to another blown up gun when you get the "right stuff."

X 2

Bullet could have been seated too deep also. This would have contribute to the potential of a problem with a full or slightly over powder charge.

[PA-Joe]

We also don't know how he determined the actual charge weight? Was he following a LEEs table or was it actually weighed? Those tables can be off quite a bit.

[buck460XVR]

One thing I did notice after I measured a new 45 fmj again my reload was that is was about a mm longer.

Could have been a combination of an overcharge and too long of OAL, pushing the bullet into the lands. Could have been a combination of an overcharge and bullet setback.....both scenarios will greatly increase pressure. Or it could be a myriad of other reasons. Double charge.....squib load, etc. Was the Ka-Boom on the first shot or subsequent rounds?

[dacaur]

Yea, its too bad the OP stopped posting... would be nice to figure out the actual issue... hopefully he comes back....

[Lost Sheep]

Originally Posted by dacaur

Yea, its too bad the OP stopped posting... would be nice to figure out the actual issue... hopefully he comes back....

I do wish he would come back with a photograph of the powder bottle. My strongest suspicion is that he used the wrong powder.

I am also very sad that a new reloader had such an experience. With all the interest among novices in guns and loading lately we have an opportunity to increase our numbers and political power. I hate to think we might lose even one.

Lost Sheep

[ATPBULLETS]

Man,,,Scarry stuff.... glad no one got hurt... very lucky...

[Unclenick]

Edward429451,

Dacaur is correct about revolver pressures, though I'll suggest another mechanism for it. Elmer Keith, Skeeter Skelton, and other old time revolver handloaders and writers reported pressures being higher with lead over the same charge as a jacketed bullet. I suspect it's because they tended to shoot relatively soft bullets, like 20:1 and 16:1 lead:tin mixes back in the day, and that the pressure upset the bases of those soft alloy bullets out into the forcing cone after they cleared the cylinder. From there, pressure had to swage the bullet back down to bore and groove diameter again. Pretty much it was the same as shooting a bullet that was much more oversized than cast bullets normally are. If you look at how soft lead like commercial swaged lead bullets can build up in forcing cones, you can appreciate the upset.

A very hard cast bullet might not do the same thing, but it would need testing to determine if that's true. I'm expecting that in very light target loads the lead produced lower revolver pressure than jacketed bullets, but that as the powder charge is increased the pressure finally gets beyond the yield of the cast bullet alloy, so it starts to upset more and surpass the jacketed bullet's pressure.

I'd also be interested to figure out if a gas check mitigates the effect. Putting strain gages on revolver cylinders is a true nuisance, though.

[Edward429451]

Learn something new everyday.

[eldermike]

There could be 2 bullets in that barrel

[j357]

^Just because you say it several times doesn't make it any more likely.

Let's see if the OP comes back with pics of the weapon and canister before saying it again.

[swampy308]

Could it be that his bullet was in the lands, he did say his overall length was a mm longer then a factory shell.

[j357]

^That remark is a good catch by the two who noted it. I believe that more importantly this is another indicator of potential deficiencies in understanding, technique and tools. Here we see the OP most likely does not have a caliper available to compare the reloads to factory rounds during set up and after production. Obviously several causes could be in play beyond the potential powder mix up.

[dacaur]

You wonder if he meant, literally, "1mm", which would be .039", or "a mm" which is "a tiny amount" Either way, .039" longer than "factory" ammo tells us nothing... My reloads are more than that longer than some factory ammo.... also, the wording "One thing I did notice after I measured a new 45 fmj again my reload was that is was about a mm longer." could mean either his was longer, or the factory load was longer.... .... lots of unanswered questions.