Final Exploding Taurus Judge Thread With Probable Solution

[jonp]

Here are links to the other 2 threads on The Exploding Taurus. I hope that some may find this entire saga useful in the future
http://castboolits.gunloads.com/show...loads-Opinions
http://castboolits.gunloads.com/show...e-Found-So-Far

The other 2 threads were full of useful insights and suggestions. Many guys stepped up to the plate including through PM's and the last PM started me thinking. Combined with some of the other comments, research on this sight and a link to a different site about velocity vs barrel length caused everything to click so here it is.

I first started out looking at the ammo and then the components. I checked that the powder was correct and because of a suggestion that the wrong powder may have been put into the bottle I was using, poured the bottle out and compared to the ETR7 I last used to load up some 38sp. All was the normal black Unique. After several suggested a double load I weighed all of the rounds and they were within a couple of grains of each other and with my hand trickling each round and using a single stage there was at least 3 times I looked into the brass and would have noticed a double as I tried loading 17.6gr of Unique in one to see what it looked like and it was near the rim easily visible. I would have caught it. Another suggested checking the scale to see if I'd moved it somehow from grains to grams as my GemPro 250 has grams, grains, ounces, carots and probably British Stones. I checked it then re calibrated it before pulling bullets and weighing the powder of a random selection of bullets. All was where it should be within .05grains. Another member suggested bullet setback so I checked the bullets and they all looked good. When I ran some over a chrony yesterday after each shot I opened the BH up to look at them and they were fine. Dismissing that I turned to the revolver and looked at everything I could think of and what members suggested. The barrel was fine showing little leading, no Glock Block, bulge or anything although the forcing cone was tilted a little down and to about 1900 with some lead jammed into the area between the cone and the frame which I didn't notice the first time around as I assumed it was powder until I scraped it with a pick and it came up shiny.

Someone pointed to the cylinder itself and a pressure spike caused by ??. Also suggested was either a manufacturers defect in the metal or a flat out blockage in the chamber evidenced by the position of the bulge in the cylinder. Even a loose boolit was brought up. Further in the thread someone said something about the cylinder free wheeling or being off and I found a different site that said this was not unknown in Taurus pistols so I checked again and sure enough the round that was in the chamber that blew had a slightly off center firing pin strike. The final clues were my reading an old thread about Unique with a mention from Larry Gibson that as you approach max with Unique it can get spikey. This was followed by an article sent to me by a friend not on this site about barrel length testing in relation to differences in velocity readings. Unrelated to this discussion but timely.

All of this brings me to yesterday's testing of 20 random rounds from the box of 100 reloads. I was looking for velocity spikes indicating pressure changes but came up with a deviation that was not out of the norm. I assumed that since I was using a BH with a 7.5in barrel instead of the 6.5in of the Taurus combined with a tighter cylinder gap the velocity would be higher. The readings I got averaged 1065fps with one at 1100fps. For some reason that didn't register as I was concerned with variation not the numbers themselves. When I got to thinking about it today I remembered I should have been in the 900fps range. That didn't sound right. When I got home I checked the book to make sure and after re-reading the article on barrel length realized that each inch of barrel should have been about a change of 25fps and here I was 200fps over. When I tested a few the first time I didn't use a chrony, I just shot a couple and they were fine so loaded them up. The extra FPS could not be explained by the barrel length, cylinder gap, slight powder difference or the difference in weight of the cast boolits. Not that much so I pulled the ammo out when I got home and looked at it again.

All looked good with a nice, heavy crimp but when I pulled out my RCBS Dial Caliper to measure them something was off. I had visually looked at them but not measured them. The lengths were a uniform 1.565in. Huh? They should have been 1.60in. What gives? Thinking back I had not used my RCBS Dial but a Franklin Armory Digital I had for several years. Getting it out and trying gave me....1.6in. Several attempts at measuring bullets, ammo and a few other things showed it consistently off.

So, long story short here is my theory based on all of this. All of the ammo had the bullet too far into the case to start due to the faulty digital caliper. Being near max loading this had the effect of raising the already high pressure to near the limit for the Judge. When firing that light gun each round had enough recoil to force the rim of the brass on the next round a tiny bit into the lead itself in the crimp groove forcing the bullet a little farther into the case raising the pressure a little more. By the third round the recoil forced the cylinder to come a little loose evidenced by the just off center firing pin strike and the leading at the top right of the cone from the 4th bullet glancing it on the way down and out the barrel. At the third round the pressure may have even been enough to weaken or crack the cylinder wall between it and the 4th round. When the hammer dropped on the fourth and final round the bullet had been forced just enough into the casing to reach the critical point and the powder pressure spiked over the safe limit for the Taurus. Not enough to damage the far stronger Blackhawk but in excess of what the Taurus was designed for. This caused the cylinder to blow up and the top strap to come off. How the brass didn't get destroyed is a mystery in itself but stranger things have happened.

Too short rounds caused by a faulty caliper + light gun + spiky pressure + bullet setback just over the critical level = BOOM.
These rounds would be safe to shoot and I did shoot 20 or so in my BH with no problem. The Taurus Judge is not made for that or is a dedicated 45lc so is not the best to be shooting these rounds in the first place let alone top end even if they are within book.

How to not have this happen again:
In a gun not dedicated to 45LC like a Taurus Judge or a lesser gun than a BH, RH etc do not approach max loadings.
Check equipment for proper function before using the ammo. I threw out the digital caliper and am ordering a much nicer dial to back up the old RCBS Dial.
Use a Chronograph to check newly loaded rounds especially if you either have not tried that loading before and doubly so if approaching max.
Pay attention to the velocity itself and not just spikes or erratic readings.

All right, long winded but I think this is a plausible explanation based on the input from the members here and some research on my own part. Any Comments on this????

[tomme boy]

Nope!

[sparkyv]

Great job on the research; we can learn from such efforts. As others have said, glad you weren't hurt.

[jonp]

Nope!

Please contribute a little more than that. If you don't have anything else then find another playground, tomme boy

[wddodge]

Thank you very much for sharing this learning experience with us. This is the kind of discussion that takes us all to the next level of reloading. I'm just thankful that you're not bleeding anywhere.

I've got 2 digital scales that I check against each other and a beam that checks the digitals. Maybe it's time to get a manual caliper to check against the digital one that I always use.

Denny

[D Crockett]

I am ever so glad that you or anyone around you was not hurt. after reading this thread I can tell you that I will NOT be getting a Judge ever. it is just to risky for me or my son to shoot. thank you for all the research you have done on this problem. and who knows you just might have saved someone from getting hurt with one of these guns. D Crockett

[Rick Hodges]

It does seem that there was very little margin for error on your revolver for it to have come apart like that because of that much bullet setback. I echo everyone else that I am glad nobody hurt.

[BeeMan]

Which way do bullets move in brass under recoil?

[Plate plinker]

Seems plausible detective. As others have said glad you can continue intact.

[rking22]

Only problem I see is that recoil would tend to pull the bullet from the case not seat it deeper. Reason for not shooting 240s in a scandium 44 Smith, bullets go out of the case and tie it up.

[knifemaker]

I have a problem with you saying that the recoil from the previous round being fired forced the bullet further into the case on the next round. Everything I have been taught is that the opposite will happen. Recoil will cause a crimp jump forcing the bullet to exit the case mouth a small amount and in some cases tie up the cylinder if the overall length of the cartridge is equal to the cylinder length to begin with.
How about the cylinder jumping time and the bullet striking the cone off center while the rear portion of the bullet is still in the cylinder and causing a extreme pressure strike? Maybe why the brass case was not split ?

[dubber123]

Tomme boy knows boolits pull in revolvers, they don't go further in the case. The boolit is a heavy thing that wants to stay at rest, the case recoils away from it along with the rest of the gun. Only autos can have a bullet driven further in the case during the chambering cycle.

Your load just isn't that hot. I stated you had a metallurgical failure in the other thread, and that is still what I believe. The fact the case NEVER split is all the proof I need that this wasn't a typical over pressure revolver blow up. If the cylinder came unglued, but the piece of soft brass survived in reloadable condition, you had a firearm failure. I'm glad you are ok, guns are made every day.

[P Flados]

There are actually 2 items that do not fit completely in the simple/moderate overpressure explantion. The unruptured case and the imprint of the case head on the frame.

The extra 200 fps above expected velocity does argue for high pressures. However, the pressures that go with an extra 200 fps in a 45 colt are not any higher than a 357 mag or a 44 mag and these do not leave an imprint of the case head on the frame.

Having high pressure and a less than perfect heat treat could lead to the start of a split at the web between cylinders on shot 3. Having #4 go to full failure starting forward on the cylinder could work with the unruptured brass.

Getting back to the revese imprint of the brass headstamp on the frame. Brass is normally softer than steel. How could brass "imprint" into good steel with minimum damage to the brass? This sounds more like either very soft steel and/or there is something we are missing.

Regardless of what we have not figured out yet, JonP is correct that his loads were probably "hotter" than he intended. The second conclusion that seems evident now is that the Judge is no Ruger and probably does not need "hot" 45 LC ammo. Good reloaders all know that mixing potentially hot loads and guns that do not have the proven track record of being extra strong is "at risk". This is a message that most of us know, but we may not be as mindfull of as we should.
Lets all strive to take this to heart.

[country gent]

Do those calipers show any wear or damage? How do they check out over the range of the units full spectrum? If you have axcess to a set of gage blocks check them a 0 .5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 and 6". Also check the depth measurement against the jaws. Ive seen the knife edges wear some over years of use but never that much. The above is to see if the calipers are off a certain amount or progressive.
Normally the recoil makes the revolver act as a bullet puller lengthening the rounds OAL not shortening them, sometimes to the point of tying up the cylinder.

[lightman]

I find it commendable that you are digging into this so seriously, and being so open minded to any error on your part. But, I'm not sure that I agree with your theory. If I'm doing the math correctly I see that you bullet was .035 of an inch deeper than you wanted to it be. I would not be worried about that, although I usually hold tighter tolerances in my loads. While your load was a little warm I'm not seeing this as a gross overload. I would however buy into the theory that your revolver may have fired without the cylinder being locked fully into the correct position. Please continue to stay in touch with us as you continue to dig into this.

[BeeMan]

Could the brass have not been destroyed because it did not see excessive pressure? Because something else gave way and relieved pressure before the brass yielded?

[dubber123]

In regards to the firing pin indent being off center, I believe Jon stated he needed a magnifying glass to tell in was "slightly" off center. Slop in the firing pin/firing pin channel and slop in lock up will produce small variances in where the pin indent will appear. For that matter I'd not be surprised to find all primer cup holes in brass are not perfectly centered, which would do the same thing. The forcing cone on a revolver gives you a good bit of leeway, and remember the nose of the boolit in this case was smaller by a good amount than the cone too, allowing for self centering to occur. I think it is highly unlikely enough misalignment could have occurred to cause the boolit to strike the frame, while still showing a near perfectly centered primer indent.

[BeeMan]

How much would seating 0.035 inch deeper in a 45 Colt case actually raise pressure , according to Quickload? I am thinking the Colt is pretty roomy, compared to something like a 9mm Luger where deep seating can cause a pressure spike. Anybody have Quickload and care to run the numbers?

[jeepyj]

Tomme boy knows boolits pull in revolvers, they don't go further in the case. The boolit is a heavy thing that wants to stay at rest, the case recoils away from it along with the rest of the gun. Only autos can have a bullet driven further in the case during the chambering cycle.

Your load just isn't that hot. I stated you had a metallurgical failure in the other thread, and that is still what I believe. The fact the case NEVER split is all the proof I need that this wasn't a typical over pressure revolver blow up. If the cylinder came unglued, but the piece of soft brass survived in reloadable condition, you had a firearm failure. I'm glad you are ok, guns are made every day.

I agree 100% with this post. Jonp sorry to disagree but I strongly feel that something just doesn't add up for me. Mainly I want to say I'm just glad your okay. Best of luck

[BeeMan]

Any name brand jacketed bullet is a good enough reference to check a dial caliper. Line up a few .451 bullets side by side and you can know if you are off more than a few thousandths in the neighborhood of typically revolver catridge overall lengths. Yes, gage blocks are nice to have, but not necessary.