Almost KABOOM with AA-5 in 41magnum load...??

[41mag]

Just got off the phone a while ago with my good friend and hunting bud. He is up at their country place and was hoping to do some load work with his 41mag. He got in one the Mihec GB molds for 41 Mag. #258 (Keith), and has poured up several dozen boolits using different alloy to decipher which might be best for his gun and hunting.

Several weeks back he had been shooting some of these same boolits using a 10.7gr charge of AA-5. He has been using the CCI-300 if I am not mistaken. Cases are trimmed to length. He has been shooting this same load with several of these boolits already, but with a tad different alloy. We are in the process of trying to soften it up a bit to keep the HP on them while at the same time, keep the loads accurate. His revolver is a S&W 657 with the solid cylinder and a 7.5" barrel. It was cleaned prior to this weekend and a patch with a bit of LLA smeared on it, was run through the barrel. Again nothing he hasn't done in the weeks prior to this.

He loaded up 6 rounds, walked out to the end of his barn and shot the first one. He said the noise and recoil was worse than when he shot my 454. He initially thought he had set the scale up wrong so he walked back inside to check it. Right where it was supposed to be. Then he considered the possibility of using the wrong powder, but there was only the one can of AA-5 sitting there. Again running down the list he checked the primers and there were only the six missing from the box he said he had just opened.

So he unloaded the rest of the rounds, and put in some from two weeks ago. He walked outside and proceeded to shoot all 5 of them into the target with a nice mild recoil and hitting the area around the bull very easily. Thinking WTH to himself, he walked back in and loaded up the other 5 rounds he had just loaded, and went back out. Again the revolver recoiled like something four times heavier, he said he simply couldn't believe it, but the recoil had pulled the other bullets out and locked up his action.

So after finally getting the powder and bullets somewhat back into place, he managed to get the action open, and remove all but the one he fired. He said he had to use a dowel and small hammer to remove the now ruined case from his cylinder. He said the primers on both of the cases were ironed so flat, that the dimple from the firing pin wasn't even visible in them.

Ok, so I immediately went through the list of things I thought it MIGHT be,
Wrong powder, primers, bullets, cases, fouled bore, fouled cylinders, OAL too long, cases too short, wrong charge weight. I'm stumped...Heck I even considered that he might have a boolit that is wedging up in the cone inside the cylinders chamber. Thinking that possibly the shoulder on the front driving band might have been jammed in just a bit causing the pressure to spike, but he shot the same exact loads that he loaded two weeks ago and nothing, nada, zilch, of an issue.

The powder was purchased new about a month to two months ago. Primers at the same time. The boolits are sized to .411 which fit his cylinder chambers perfectly, and the bore was checked at .410. The alloy has been Isotope ingots he purchased from Muddy Creek here on the board, followed up with some Core ingots he smelted down and poured up week before last.

We're looking for something to grasp onto here and determine what the issue is. I told him to bring home the remainder of the loads he had left that he has been shooting and that shot well, and also the can of AA-5 it came out of. To contact Accurate tomorrow ASAP and find out what their take on it is.

Granted the powder hasn't been stored in a total climate controlled area, but it hasn't been exposed to much over 80-85 degrees nor any type of humidity. It's been kept inside an insulated room which is built inside their barn, and has kept plenty of powder good for years and years. Now if it were some of my old 97 era stuff that had sat out on the back porch shelf in heat and cold for years on end I would know right off the bat, especially since I had to pour out several jugs of it that went south on me. Another thought was that the powder was simply warm from sitting in the room, but he said this was first thing in the morning so it hadn't gotten warm yet. Since he keeps it in a plastic box sitting on the concrete floor it is usually cooler in there anyway.

Being brand new and only being a couple of weeks since he shot some of the same powder, from the same jug, has us both a bit twisted up. Everything else being the same as well. He left everything set up and ready to go the last time he was there, so nothing has changed, at least that is obvious anyway. The measure he used was checked, the scale was re-zeroed and checked with the standard, and like I mentioned above everything else was gone over as well.

Anyway possibly someone here has an answer or question that I might not have thought of. If so please feel free to post it up, cause this has us both baffled.

[Rockchucker]

Have you pulled any of the boolits yet and checked the powder weight?

[geargnasher]

If that's the same can of AA#5 he used two weeks ago, perhaps he accidentally returned some much faster powder to the can from a different reloading session? Ask him to pull the boolits (again, since the gun did it once!) and have a gander at the powder. It's either too much or wrong kind/mixed.

Gear

[Dennis Eugene]

My first thought excatly. pull one of the bullets and weigh the charge. Dennis

[41mag]

Yep both idea were suggested to him by me.

He doesn't have anything faster to have sitting around, other than Unique, and he hasn't even opened it up yet. Even so that would pretty easily seen in the hopper of his powder measure, especially when he dumped a charge to check it's setting.

My first thought was too much, but he said he rechecked the weight, and zeroed the scale and checked it again to be sure.

He said he didn't have the puller up there with him, so I told him to load it all up and haul it on home. I personally would like to be there when he pops the top on them.

I have known this fellow for going on the better part of 25 years, and he is a very attentive handloader. If something distracts him he simply stops what he is doing and starts over. For him to call me and tell me what happened, it must have shook him pretty hard.

Like I said, this one has us both two blocked.

[william iorg]

If he changed his alloy to a softer alloy that could be the problem. If you have a hardness tester test the previous batch with the current bullet.

[308w]

My vote is for a double charge, could be something hinky with that can of powder but I'm thinking too much powder.

[Ben]

I don't think that a " child mild " load vs. cylinder locking up load could be explained by hardness of alloy alone. Just my opinion.

The kind of propellant, or the specific charge weight of propellant is most likely at the base of all this.

Ben

[LUBEDUDE]

The kind of propellant, or the specific charge weight of propellant is most likely at the base of all this.

Ben

Most logical

[725]

Any chance his powder measure had some other powder bridged across from another loading session. Not likely but possible a mixed powder in the measure, now gone.

Curious

[41mag]

The alloy was changed, but not by much. He purchased some alloy from Rotometals, some 20-1 and some Lyman #2. He also had poured up around 50ea or so using Iso core and Iso ingot alloy and from it all had equal numbers which were AC, and WQ. He for the most part was simply looking to see what the differences were in how they shot. I was told the ones used on these rounds were the straight AC core alloy. We're both looking at expansion with the different alloy we have to work with, and the Core has shown to be about as good as we need for hog hunting. The core alloy works the best in my Rugers, but I am pushing them a bit faster. The ingot alloy hsa worked better for him. But like I said he is still working with them and trying to see what is the most accurate.

He has been shooting both the Iso core and ingot, in the previous trip up, and before that had been using some commercial cast he purchase from Montana Bullet Works in the 15 BHN. Nothing he has shot so far has exceeded 1200fps loads, well till this happened.

He will be bringing me the loaded rounds both from the previous loads and this weekend. He said he didn't want to mess with it and would rather I did it.

As for the different powders, he has only worked with the AA-5 for the past month or more with this revolver, and when he was done the last trip up, he dumped the remainder of the hopper back into the original container. He left everything set. This weekend he filled the hopper once more and then verified the setting before loading the initial 6 rounds.

If I see him at work today I will get the rounds and have them pulled down sometime this evening. I will do a close examination of each one, as well as checking the weights of both powder and boolit. I will also remove the primers and compare best as I can to factory fresh ones, just to see if possibly that might be it. I highly doubt it would be, as he just purchased a brick of them on the same ticket as the powder. THey are all he is working with at all so chances of getting them mixed up with something else would be highly unlikely, but I'll look anyway.

[garandsrus]

Its not the alloy.....

[rockrat]

Concur on checking powder weight. I believe there was another on this board that loaded ammo and had something akin to what happened to your friend. Turned out that the scale, that he checked again, had been incorrectly set and he was throwing a charge with 5 more grains of powder, than what he wanted.

[w30wcf]

It certainly appears that the powder in those cartridges is likely not AA-5.....unless like others have suggested....an increased powder charge.

Is there a possibility that even though the can says AA-5, the powder contained therein is not AA-5(?).

Is there a possibility that another faster burning powder in the measure was not emptied before the AA-5 was dumped in(?). I know of one instance where that happened. Thankfully the gun survived but the back of the case melted a bit (rifle).

w30wcf

[odfairfaxsub]

alloy will not cause your shells primer to flaten in this situation.

[geargnasher]

Concur on checking powder weight. I believe there was another on this board that loaded ammo and had something akin to what happened to your friend. Turned out that the scale, that he checked again, had been incorrectly set and he was throwing a charge with 5 more grains of powder, than what he wanted.

That would just about have to be the issue, that or powder bridging. I keep an electronic scale handy to double check my beam scale, not for accuracy but to give me digital numbers to verify my beam settings. Once I undercharged a light pistol charge and stuck a boolit because I used the tenths instead of the ones weight. I still don't know how I did it, even checked the weights several times, but my brain was in the wrong gear that day.

Gear

[gray wolf]

Wrong powder--- or to much of the correct powder.
Ain't the metal, not a blocked bore if it happened more than once.
The cases were over charged in some way.
Bullets should have been pulled after round one.
lucky guy, I am glad he is OK and hope he finds out what happened.

[rexherring]

Has to be either wrong powder or overcharging. I've been shooting AA#5 at 11 grs in my .45 BH a lot and never had an issue no matter how hard or soft the boolit. It is very easy to overcharge the load as it doesn't fill much case in fact I could probably get a triple charge to fit. That;s why I use a Mag light to inspect every case before seating the boolit and weigh every 10th round.

[ColColt]

Not that it would cause an even close to kaboom issue but AA#5 definitely doesn't need a magnum primer. I learned long ago not to have two different powders on the bench at the same time. I had a can of Universal and a can ofHS-6 not far apart but had been using Universal. After emptying the powder measure with had about half a cup of powder left and put it in my little cup for dumping back in the canister, I realized I had just dumped all that Universal somehow into the can of HS-6.

That's what happens when you have more than one powder close by and are distracted. Would it have caused a kaboom? Don't know but I had to thrown the entire can of HS-6 away.

[paul h]

I've never used that paticular powder, but have used enough different handgun powders in various cartridges to know that occasionally there are combinations that just behave strangely. I've had powders I've used for years that have been consistant in one chambering that in a different cartridge behaved strangley with wildly varying velocities and even velocities that go down as powder charges increase. The only real way to possibly know what's going on is to chronograph loads, but with two instances of that in his gun I'd advise him to immediately discontinue using that powder.

The only time I've had a mild load give one wild overpowered load is in a friends 475 linebaugh. He had some medium loads with I believe blue dot and he let me fire a cylinder full. I think it was the 3rd shot that had hellacious recoil and muzzleblast and he had to pound the case out of the cylinder. I would be highly suprised if it was a double charge.

I think there are some chambering/powder/bullet weight combinations where occasionaly instead of the powder burning normally it essentially detonates causing a high pressure spike.

That's one reason I tend to stick with the most common and popular powders for a given chambering, enough people have shot those combos to be able to provide somebody having found out if there is a tendancy for erratic behaviour.