johnb Posted December 12, 2006 Share Posted December 12, 2006 Here are a few pictures of what's left of one of my favorite's I've been trying to work up a good load for my 29 using 300gr bullets and looking to push them at about 900-1000fps for a 50yd steel match that I shoot. I decided to try a moderate load using 300's instead of my normal full power 240 loads because the gun was showing a bit of gas cutting on the top strap. The load I was trying when this happened was 10.5gr of Blue Dot with a 300gr LSWC. I've been reloading for nearly 20 years and I'm careful about everything I do. I use Dillon 650's to load for my handguns and do all my rifle reloading on a single stage. I've been working with a 650 for several years and am comfortable using them. On Saturday, I went to the range with several different loads to test. I was shooting 50yd groups and chronoing but didn't come up with anything I liked. Went back to the range on Sunday with six more loads and had fired a six shot group of each. I then set up the chrono and started to shoot another group of each to check velocities. Starting with the 10.5gr of Blue Dot my velocities were 889, 917, 771 and then BOOM!(which chrono'ed at 859fps) The gun is destroyed but I walked away without a scratch. I thank God I was the only one around and nobody else got hurt!! So, was this a double charge or a very light charge that detonated? I can't imagine how I could get a double charge using the 650 because I never stop mid-stroke and the press auto-indexes. I guess it's possible. The other possibilty is the light charge that detonated. I've heard both sides but don't know for sure if a light charge could detonate. Yesterday, I pulled the remaining loads and they all weighed within a tenth or two. I also checked the weight of each powder charge thrown until the powder hopper was empty (about another 90 or so charges) and they weighed within two or three tenths. Still wondering why it happened. Any thoughts? Link to comment Share on other sites More sharing options...
DougCarden Posted December 12, 2006 Share Posted December 12, 2006 Wow, glad you are ok! Sorry about the gun, but you are what is most important! With that load and powder....is it a download from a higher load? Some big bore loads tell you not to down load from their minumums. I dont have any big bores so I have no experience with that combo. It appears that you had the round detonate, which in turn took the cylinder. We know that there was no bore obstruction, I would postulate that for some reason the powder detonated instead of burned properly....why, hell I dont know either I am taking my time learning how to load .223 right now, going slow as well. Thanks for the reminder to be damn careful! Hope to see you in the spring! DougC Link to comment Share on other sites More sharing options...
Carmoney Posted December 12, 2006 Share Posted December 12, 2006 Oh wow. John, really glad you weren't hurt. Link to comment Share on other sites More sharing options...
Patrick Sweeney Posted December 12, 2006 Share Posted December 12, 2006 No idea of the cause, but one note on topstrap cutting: don't sweat it. with a few exceptions, it is a slef-limiting problem. the gas jet loses velocity quickly, and once the strap is cut a bit, it usually stops. Now,k if you're loading 180 JHPs to insane velocities, yes you're going to get more cutting. But the cutting you'd have gotten with 240 lead would have settled down without much more than cosmetic problems. I agree with the others; ouch. Link to comment Share on other sites More sharing options...
38superman Posted December 12, 2006 Share Posted December 12, 2006 (edited) I don't have any load data at hand so can't speculate about the viability of 10.5 of Blue dot behind a 300 grain LSWC. I do know that a 300 gr bullet is way heavy for a 44 mag and would have to be seated pretty deep. I can't help but wonder if you had a bullet set back in the case. I also notice that you had quite a lot of variance in velocity from your first three rounds. Are you quite certain it was Blue Dot? Any possibility that the powder was mis-labeled or contaminated by being accidentally mixed with some other powder? Tls Edited December 12, 2006 by tlshores Link to comment Share on other sites More sharing options...
HSMITH Posted December 12, 2006 Share Posted December 12, 2006 I don't know for sure what caused your KB but I do know Blue Dot is VERY VERY sensitive to pressure. You can be working up with everything going fine, add a tenth and have hard stuck cases with no other changes. Add another tenth and things can go really badly..... Wicked nasty powder with NO warning you are close to the edge. Your load SHOULD be OK, and with the chrono running there should be no chance of a bullet stuck in the bore. How badly were they leading the chambers and barrel? From the pictures it looks like significant leading, and that can be enough to put Blue Dot over the edge. Could be that the lack of load density also helped light the powder in an abnormal way, that would also explain some of the velocity variations in your chrono readings. Blue Dot is extremely position sensitive in low load density situations as well. Maybe all the stars aligned just right and piddled down your back with a couple of variables just far enough out of whack for things to go soooooo badly. Glad you are OK, too bad for the gun. Link to comment Share on other sites More sharing options...
dillon Posted December 12, 2006 Share Posted December 12, 2006 Years ago the 38 Super major shooters went away from Blue Dot due to severe lot-to lot variations. A question, are any of the primer strikes off center? It could be the cylinder mis-timed, and the bullet went into the edge of the barrel, and not the bore. Another, much less likely possibility is two bullets in the same case. This HAS happened. The seat die was gummed up, a bullet stuck in the seat die, then was reseated into the next case. The operator failed to associate the case without a bullet in the loaded cartridge bin. The last known instance of this occured in 44/40 caliber, and was written up in SHOOT magazine a couple of years ago. A detonation is theoretically possible in any cartridge with light loads of double based powder, but unlikely, especially in this instance. Between the 10.5 grain of powder and the longer 300 grain bullet, I am not sure there is enough room for the powder to spread out that much. The more likely possiblity is that of dealyed powder ignition. If the powder ignited poorly, the bullet could have moved up into the bore, then the rest of the powder charge ignites. If this happens, the bullet acts as a bore obstruction. Did you notice any hangfires, or vertical stringing of your shot group? These are both indicators of bad ignition. Link to comment Share on other sites More sharing options...
johnb Posted December 12, 2006 Author Share Posted December 12, 2006 Wow, glad you are ok! Sorry about the gun, but you are what is most important!With that load and powder....is it a download from a higher load? Some big bore loads tell you not to down load from their minumums. I dont have any big bores so I have no experience with that combo. It appears that you had the round detonate, which in turn took the cylinder. We know that there was no bore obstruction, I would postulate that for some reason the powder detonated instead of burned properly....why, hell I dont know either I am taking my time learning how to load .223 right now, going slow as well. Thanks for the reminder to be damn careful! Hope to see you in the spring! DougC The load was at the minimum suggested starting from Hercules manual. They suggest 10gr to a max of 12gr of Blue Dot. I don't have any load data at hand so can't speculate about the viability of 10.5 of Blue dot behind a 300 grain LSWC. I do know that a 300 gr bullet is way heavy for a 44 mag and would have to be seated pretty deep. I can't help but wonder if you had a bullet set back in the case. I also notice that you had quite a lot of variance in velocity from your first three rounds. Are you quite certain it was Blue Dot? Any possibility that the powder was mis-labeled or contaminated by being accidentally mixed with some other powder? Tls I'm certain it was Blue Dot. I loaded the bullet as deep as I could and still get a good crimp. I had checked several of the last rounds of each group before I shot them to see if the bullets were moving and they looked fine. I had chrono'd the loads I had shot on Saturday and got decent SD's, usually in the single digits to low teen's. The chronograph usually reads a bit low for the first shot of every string but I don't know why a got the 771fps reading unless the charge was a little light. And then the next one seems to have been even lighter. I don't know for sure what caused your KB but I do know Blue Dot is VERY VERY sensitive to pressure. You can be working up with everything going fine, add a tenth and have hard stuck cases with no other changes. Add another tenth and things can go really badly..... Wicked nasty powder with NO warning you are close to the edge.Your load SHOULD be OK, and with the chrono running there should be no chance of a bullet stuck in the bore. How badly were they leading the chambers and barrel? From the pictures it looks like significant leading, and that can be enough to put Blue Dot over the edge. Could be that the lack of load density also helped light the powder in an abnormal way, that would also explain some of the velocity variations in your chrono readings. Blue Dot is extremely position sensitive in low load density situations as well. Maybe all the stars aligned just right and piddled down your back with a couple of variables just far enough out of whack for things to go soooooo badly. Glad you are OK, too bad for the gun. They didn't seem to be leading the barrel badly. It looks looks bad now in the pictures(after the explosion) but it really isn't. I checked to see how much free space there was and it looks like about 100-150 thousandths with 10.5gr Link to comment Share on other sites More sharing options...
MichiganShootist Posted December 12, 2006 Share Posted December 12, 2006 That's a bummer... glad you are Okay. Is that a bullet stuck in the forcing cone?????? Link to comment Share on other sites More sharing options...
johnb Posted December 12, 2006 Author Share Posted December 12, 2006 Years ago the 38 Super major shooters went away from Blue Dot due to severe lot-to lot variations. A question, are any of the primer strikes off center? It could be the cylinder mis-timed, and the bullet went into the edge of the barrel, and not the bore. Another, much less likely possibility is two bullets in the same case. This HAS happened. The seat die was gummed up, a bullet stuck in the seat die, then was reseated into the next case. The operator failed to associate the case without a bullet in the loaded cartridge bin. The last known instance of this occured in 44/40 caliber, and was written up in SHOOT magazine a couple of years ago. A detonation is theoretically possible in any cartridge with light loads of double based powder, but unlikely, especially in this instance. Between the 10.5 grain of powder and the longer 300 grain bullet, I am not sure there is enough room for the powder to spread out that much. The more likely possiblity is that of dealyed powder ignition. If the powder ignited poorly, the bullet could have moved up into the bore, then the rest of the powder charge ignites. If this happens, the bullet acts as a bore obstruction. Did you notice any hangfires, or vertical stringing of your shot group? These are both indicators of bad ignition. I'll have to check my targets tonight, but that particular load may have actually strung out vertically. I remember that on one group but am not sure if it was the load in question. I shot everything from single action and believe the timing was fine. I check that relatively frequently on all the Revo's I shoot regularly. That's a bummer... glad you are Okay.Is that a bullet stuck in the forcing cone?????? No, the bore is clear. Link to comment Share on other sites More sharing options...
slflr Posted December 12, 2006 Share Posted December 12, 2006 Did two rounds go off? Link to comment Share on other sites More sharing options...
johnb Posted December 12, 2006 Author Share Posted December 12, 2006 Did two rounds go off? No. The 'opened up' one is the culprit and the smashed one was the previously fired case. The live round in the next chamber to the right was dented. Link to comment Share on other sites More sharing options...
R112mercer Posted December 12, 2006 Share Posted December 12, 2006 First off, I'm glad you're OK, guns are replaceable, hands aren't. I have heard of light charges detonating, but usually it's for super light loads with lots of case capacity (esp. HBWC's in .357 mag brass). Usually with the slower magnum powders when the round fails to ignite (usually due to weak crimp, primer not hot enough, or insufficient charge of powder) the round just squibbs and blows powder everywhere. Bullet setback would be unlikely because the rounds were shot in a revolver, which has a tendency to telescope rounds under recoil. Just my $.02 Link to comment Share on other sites More sharing options...
revchuck Posted December 12, 2006 Share Posted December 12, 2006 John - I have no idea what may have caused this, but I just wanted to add my voice to those glad you're okay. Looks like you might be able to salvage the scope. Was that old powder, or new? I'm just wondering if it may have deteriorated and the decomposing powder caused this. Link to comment Share on other sites More sharing options...
TDean Posted December 12, 2006 Share Posted December 12, 2006 Yikes! I still have some 300gr loads that I tested at 1100 fps from my 629-4 Mountain Gun (H110 powder). Link to comment Share on other sites More sharing options...
Carmoney Posted December 12, 2006 Share Posted December 12, 2006 When we develop the legend of John's lost 29 over drinks at Nationals next year, we're definitely going with dillon's theory that John put in two bullets. Link to comment Share on other sites More sharing options...
johnb Posted December 13, 2006 Author Share Posted December 13, 2006 John - I have no idea what may have caused this, but I just wanted to add my voice to those glad you're okay.Looks like you might be able to salvage the scope. Was that old powder, or new? I'm just wondering if it may have deteriorated and the decomposing powder caused this. I think the scope is pretty much gone as well. Both turrets were blown of off it and I could only find the one in the picture. I thought about calling Leupold to see if it was salvagable. The powder is at least 7 or 8 years old. Generally, if it's kept at a steady temp and is not exposed to excessive humidity, it should last quite a while. It's always been stored indoors and we don't get much humidity in Colorado. But who knows? When we develop the legend of John's lost 29 over drinks at Nationals next year, we're definitely going with dillon's theory that John put in two bullets. Now I'm even more confused If there were two bullets, there shouldn't have been any extra space in the case to allow a detonation Link to comment Share on other sites More sharing options...
mikey357 Posted December 13, 2006 Share Posted December 13, 2006 GLAD you're Okay...looks like the GUN is FUBAR, tho'...I'd be interested to hear what Leupold says about the scope...on the same note, the RINGS look okay...and the grips...what're you gonna do with those grips???... ....mikey357 Link to comment Share on other sites More sharing options...
HSMITH Posted December 13, 2006 Share Posted December 13, 2006 John, next time you try this start with 8 grains of Unique, don't go over 10. Makes a nice 300 grain load from 800 to almost 1000 fps. Link to comment Share on other sites More sharing options...
johnb Posted December 13, 2006 Author Share Posted December 13, 2006 GLAD you're Okay...looks like the GUN is FUBAR, tho'...I'd be interested to hear what Leupold says about the scope...on the same note, the RINGS look okay...and the grips...what're you gonna do with those grips???... ....mikey357 I'll let you know what Leupold says about the scope, but the grips? I'll be keepin' those babies Link to comment Share on other sites More sharing options...
Carmoney Posted December 13, 2006 Share Posted December 13, 2006 John, I believe for two 300-gr. bullets stacked on top of each other in the case, the preferred charge is 0.0 grains of Blue Dot. You'd have to check with Aerosigns on this, that's more his area of expertise. (Sorry about your gun....hope the grim humor makes you feel a little better.) looks like the GUN is FUBAR, tho'... Ah hell, looks to me like there's three perfectly good chambers left. How many rounds you need in the gun for that silhouette crap anyway? Link to comment Share on other sites More sharing options...
cliffwalsh Posted December 13, 2006 Share Posted December 13, 2006 Ah hell, looks to me like there's three perfectly good chambers left. How many rounds you need in the gun for that silhouette crap anyway? I'd send it to TK and get it moonclipped...order a dozen half moons and your back in action guys are paying all kinds of money for the low torque Ti cylinders, you may have increased the value of the gun Link to comment Share on other sites More sharing options...
Waltermitty Posted December 13, 2006 Share Posted December 13, 2006 Ah hell, looks to me like there's three perfectly good chambers left. How many rounds you need in the gun for that silhouette crap anyway? I'd send it to TK and get it moonclipped...order a dozen half moons and your back in action guys are paying all kinds of money for the low torque Ti cylinders, you may have increased the value of the gun Yeah, but he's gonna get one heck of a high-speed wobble when he's really strokin'. Link to comment Share on other sites More sharing options...
johnb Posted December 13, 2006 Author Share Posted December 13, 2006 Ah hell, looks to me like there's three perfectly good chambers left. How many rounds you need in the gun for that silhouette crap anyway? I'd send it to TK and get it moonclipped...order a dozen half moons and your back in action I'm one step ahead of you on that one. I had Tom moonclip it several years ago so I'll just snip the ones I have in half and be good to go! The teeter-totter action of the scope is gonna make hitting anything a real bitch, though!! Link to comment Share on other sites More sharing options...
Carmoney Posted December 13, 2006 Share Posted December 13, 2006 The teeter-totter action of the scope is gonna make hitting anything a real bitch, though!! Got any JB Weld around the house, John? Link to comment Share on other sites More sharing options...
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