My first double charge? Just may be my last.

[tdogg]

How did you determine the OAL for your loads?

I use the barrel/chamber plunk? test. Its difficult to explain. I basically drop a bullet and casing in the chamber(with the barrel removed) and set the OAL  so that the casing is flush with the "barrel hood/lug?-the longest part of the barrel on top". For the first few, i start too long and when its flush, i set my seating die there
Forgive my ignorance, but this is the method i have been using. Like I said, I am no expert.

Charlie,

Your OAL method is slightly flawed.  You want the case to headspace on the mouth.  Essentially you want the case to be free of the lands of the barrel rifling.  If you are just looking at the barrel hood to verify if it is flush you may still be loading too long (read into the lands).

If you want to verify your max OAL with the plunk test you need to make sure the case will spin when in the chamber.

Process:

Take a sized and unflared case and seat a bullet too long.  Incrementally seat it deeper and deeper (0.005 increments) until the cartridge when dropped into a loose barrel falls under it's own weight into the chamber and makes a plunk sound.  Then verify it isn't into the lands by lightly pressing with your thumb on the case head and verify it will spin freely.  Then invert the barrel and ensure it falls out under it's own weight.  If it passes all these tests that is your maximum OAL.  Then you would subtract 0.015-0.020 to determine your usable OAL for loading that bullet in that barrel.

Given your top two rounds set back considerably, I would check your bullet retention.  Take a seated bullet or finished cartridge and measure the OAL.  Then press the bullet end of the cartridge into your bench (or other hard surface) and verify it didn't set back any (remeasure the OAL).  If it did, then you need to look at your sizing process/die.  I push hard enough to dent my workbench (soft pine 2x6).

If your willing to seat and crimp with the same die, you can install a RCBS lockout die that will lock up your press when an under/over charge occurs.  I run it on my Lock n load but I have 5 positions for dies...  The RCBS die isn't sensitive enough to prevent minor shifts in powder charge but will let you know about doubles.  You should still visually verify powder in the case before placing the bullet.  More info here: https://ultimatereloader.com/2010/09/19/rcbs-lock-out-die-part-i-theory-of-operation/

Glad you still have all your digits!

Good Luck,
Toby

[painter]

Good catch, Toby.

OP...check your loads in the chamber for the ability to spin when fully inserted

[Wobbly]

How did you determine the OAL for your loads?

I use the barrel/chamber plunk? test. Its difficult to explain. I basically drop a bullet and casing in the chamber(with the barrel removed) and set the OAL  so that the casing is flush with the "barrel hood/lug?-the longest part of the barrel on top". For the first few, i start too long and when its flush, i set my seating die there.

Forgive my ignorance, but this is the method i have been using. Like I said, I am no expert.

First of all, very glad you're OK. I don't see one glaring issue here. I see several possible small errors that could have simply aligned and then erupted.

• First of all, can we please verify the caliber ? I don't see the caliber mentioned anywhere. 200gr is used in several 1911 cartridges. Everyone has assumed 45ACP ??

• Primarily, as per Tdogg's comments, your reloading process is not refined nearly enough. It needs to be re-thought to provide room for physical variations to exist, and needs to provide more safety checks. As per Tdogg, your method of finding your Max OAL is (to put it lightly) awful. OAL has nothing to do with the barrel hood, and everything to do with head spacing.

[We can help you improve your process, but obviously you need to learn more and move on from whatever source taught you this very poor method.]

• I don't see W231 as an issue. The lesson I probably would draw from that portion of the tale is that... You are not looking into the cartridge case before seating the bullet. And maybe this is because you simply cannot see in there. I highly suggest a lighting system from KMS Squared  Click Here

• If you are needing to stop to fiddle with primer size in the middle of reloading, then your basic brass sorting process is not very refined. Large/Small primers is now a way of life with 45ACP. And because it is, you need to focus on it, or change to a caliber that doesn't have this complexity.

• Finally, allow me to introduce my own reconstructed scenario that might go a long way towards a total explanation. This is only how I see this unfortunate event unfolding, and may/ or may not have any relevance....

You usually load 200 or 230gr RN for this gun. You were trying Hornady XTP for the first time. Your very basic process does not allow for changes in OAL driven by the bullet, and so you use the same OAL you've always used. The SIG chamber is a tighter-design. Chamber clearances were already nil-to-none with the RN, now with the XTP they are non-existent. That is to say, the XTP bullets are jammed into the rifling which raises chamber pressure. One might even be long enough to allow a firing in OOB condition, as per Mr Painter.

And I think that's what happened. The new-to-you bullet starts a sequence of events that's simply waiting on one round to be just 0.010" longer than the rest to cause real havoc.



Have your gun checked by a local gunsmith, but I believe you'll find it's OK. At the most, you'll probably only need some new grips and maybe a magazine.

All the best. 


PS. The process we use for finding Max OAL is here.... https://czfirearms.us/index.php?topic=103620.0   And in that document, the first 3 figures give a lot of background information as to WHY these steps are necessary. Bottom line, we're not going to "give you a fish", but rather give you the knowledge to become a "fisherman". Big difference.

[Dan_69GTX]

Out of curiosity... What did the mag look like?

[charlielikesczs]

The magazine looks fine. And it is .45 ACP. Thanks to all for taking the time to share some knowledge.
You all make excellent suggestions and I will definitely “refine” some things throughout the entire process.
Charlie

[Wobbly]

O.A.L- i don't remember the exact length but i did set them in SIG 1911 chamber until the base of the cartridge was flush with the barrel hood?

Forgive me, but reading between the lines of your post.... Of all the positive steps you could take TODAY, this may be the biggest of any of them... It's more important than OAL, more important than powders, more important than bullet selection....

You MUST get a 59 cent school notebook and start taking notes on your loads. That's the biggest step you can take, as far as your personal safety. It is impossible for anyone to remember after 5 days, all the detailed dimensions involved in building a cartridge. If you don't know where you started, then how can you possibly re-trace your steps when corrections are called for ?

A reasonable system I can highly recommend is to get a basic school "lab notebook" or other type of 8.5 x11 fixed page binder. Hopefully one notebook for each caliber. Then, since each bullet is going to have its own discrete loading dimensions, allow one whole page per bullet.


Typical page from one of my reloading notebooks. Bullet name at top. Bullet physical dimensions.
The OAL to use with this bullet. Load information. The loads and results, some with chrono data.

So at the top of the page record all the bullet dimensions. Then find the Max OAL and record that. Then decide upon what OAL you'll use for reloading that one bullet. Write all that down. Under all that you can record load data, powders you've used, impressions, accuracy, velocities, dates, etc. In that way if you like ithe load, you can return to it. And if something goes wrong, then you have a basis for research.

This "tractability" is supposed to be part of every reloader's standard process.

Hope this helps.

[Unamower]

Just IMHO...

I've seen similar incidents where the grips break and the gas comes down through the magwell usually blowing the mag out. In these incidents they were either case head separations or firing out of battery. Too bad you don't have the fired case to inspect. Also, with either of those scenarios a standard powder charge would be sufficient to blow the grips off. Do not want to discourage review of your reloading  process, which everyone should do now and then, but it may not have been a "double charge" after all.

[lewmed]

I agree with Unamower

[newageroman]

Thanks for sharing, glad it wasn't worse.

Missed index = double charge on the 550. That's why a lot of 550 owners will just pull all cases if they have to stop. Harder to do with the 650, but still possible. The other reasons sound more likely though.

A couple things that have helped me: I took the notebook idea and use excel spreadsheet. After working up a load with a new bullet/new COAL as wobbly described, write the coal on the outside of a non primed, non powder case with a sharpie and keep it as a reference bullet. For lighting, I used a 20 ga shell in the center hole, that holds a small led flashlight. When I REALLY want close inspection, hook the 12$ ebay boresnake up to my computer/monitor. When determining COAL, do it with a sample of 5 bullets and take the avg, as no bullet is perfect, they are all like snowflakes.

[Wobbly]

Missed index = double charge on the 550. That's why a lot of 550 owners will just pull all cases if they have to stop.

I'm sorry. Don't mean to start another bunny trail topic, but I'm not exactly following this statement.

The 550 is a progressive. As such it usually has a cartridge case in each of 4 shell plate stations. If the operator misses the shell plate advance, then there are still 4 cartridge cases in the shell plate. And the state of each one of them indicates where the machine is in the loading cycle.

I don't want to ding anyone's safety procedures, but of all the 550 owners I know, none take this extreme measure.

 

[newageroman]

If you miss the advance double charge, right, that's basically what I've heard is possible. Its been years since I've been around one, but the auto advance feature of the 650 helps, but doesn't eliminate it.

[charlielikesczs]

For the record, I measured all the remaining bullets from the suspect batch and the longest OAL was 1.200" with most closer to 1.197. Not sure if that seems out of wack or not with anything you folks are ending up with on OAL.
I dont have the gun right now so i can't perform a proper plunk/push/spin test.(Its at the gunsmith getting looked at) but I will do this when I get the gun back if the barrel checks out good.
I've gone through all my remaining .45 brass. All with small pistol primer pockets are in the trash.
I started a logbook when I began reloading but I found a few loads that I really liked so I got complacent. Not anymore. I will do a paper log on EVERY bullet and a spreadsheet as a backup.
If my process gets interrupted for any reason, I will clear the shellplate. and finish the rounds one a a time. As well as buy a better LED light.
You gentlemen were spot on with the "new to me round" and my failure to allow .010-.015 for variation in bullet size.
I was 100% positive that this was my fault before I decided to put this out there. I was 0% sure of what exactly I did or was doing wrong. I posted this here because you folks are a treasure chest of experience/knowledge and I wanted to learn from my mistakes.
THANK YOU- to each and every one of you for taking your time and sharing your wisdom.

[Dan_69GTX]

Yup, excellent knowledge here!

FWIW trade the small primer brass.  I do that.  Only I want the small so I trade for them.

[Wobbly]

For the record, I measured all the remaining bullets from the suspect batch and the longest OAL was 1.200" with most closer to 1.197". Not sure if that seems out of wack or not with anything you folks are ending up with on OAL.

The Max OAL comes from the way the bullet and case interface with the barrel. Any tester needs all 3 components to make the comparison.... which eliminates most of us who lack a SIG barrel.

I don't have the gun right now so i can't perform a proper plunk/push/spin test. It's at the gunsmith getting looked at, but I will do this when I get the gun back if the barrel checks out good.

I came here particularly to suggest this very action, so good thinking on your part. Even if the barrel is damaged, you'll still be able to do the static Max OAL testing. You simply won't be able to test fire it afterwards.

I've gone through all my remaining 45 brass. All with small pistol primer pockets are in the trash.

Lots of people prefer the SPP for use in 45ACP. I'd suggest you get them back, and post them on Brass Bucket where you can swap them 1:1 with someone in the opposite position. This is a FREE service (it's the CraigsList of brass) and is run by one of your fellow members here at the Orig CZ Forum. http://brassbucket.net/

I started a logbook when I began reloading, but I found a few loads that I really liked, so I got complacent. Not anymore. I will do a paper log on EVERY bullet and a spreadsheet as a backup.

You'll see. Very small differences between brands of bullets... even though they look identical at first glance, can make a huge difference.

If my process gets interrupted for any reason, I will clear the shellplate. and finish the rounds one a a time. As well as buy a better LED light.

1. Start keeping a reloading notebook again
2. With each new bullet start a new notebook page
3. Do the "push test" and working with the bullet and barrel, accurately determine your Max OAL
4. Then determine what your OAL will be for whenever you load that cartridge with that bullet (doesn't have to be Max OAL !!)
5. Pre-sort your brass
6. Schedule reloading time to be at an off-peak, low stress time

You gentlemen were spot on with the "new to me round" and my failure to allow .010-.015 for variation in bullet size.
I was 100% positive that this was my fault before I decided to put this out there. I was 0% sure of what exactly I did or was doing wrong. I posted this here because you folks are a treasure chest of experience/knowledge and I wanted to learn from my mistakes.
THANK YOU- to each and every one of you for taking your time and sharing your wisdom.

It's very encouraging to see that your quest for safety, continued education, and process improvement, out-weigh your pride. Not many guys would have posted those photos, and even more would said something like... "A friend has this problem...".    So you get all the credit on this one.

Speaking personally for myself, I only know what I know from falling flat on my face so dang often !

Anyway, in the interim we clean and sort brass, and find a couple of pieces we can use for the telescoping push test.

 

[newageroman]

Brass Bucket is closed to new posters at this time, but I can add you as a user if you want to sell brass. Same goes for anyone here. I had it open to post without verification, but spam quickly changed that.

Since a lot of people shoot 9 and 45, more are opting for SPP 45 so they don't have to change components/setup. 1 for 1 trade is great deal. If I shot more 45 I'd sell all LPP and make the switch too.