What Caused My Squib?

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carnaby

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Had my first ever squib today and I want to figure out what was the cause. I loaded up 12 grains of H322 with a 160 grain Nosler Accubond for 6.8 SPC. My barrel won't stabilize the bullet with this load and it gives a big fat key-hole. I don't care about this.

I shot some other similar loads to this one, up to 20 grains of H322, and also 18 grains, 16 gains, 14 grains, and 12 grains. The 12 grain load gave about 1000 fps or so says my chrony. Anyway, after progressing through one load at each of these powder charges, I wanted to see how consistent would be the muzzle velocities.

Also note that the 16 and 14 grain loads cycled the action, but the 12 grain load did not. This load fired successfully and was not a squib. When I pulled the charging handle on my AR to eject the spent case, it came out easily but was covered with carbon fouling on the outside.

I loaded up a few more 12 grain cartridges into the mag, chambered one, pulled the trigger, and *click*. That's the only sound I heard. Thought this was funny, ejected the round and all that came out was an empty case with carbon fouling on the outside, just like the last one. At that point I figured "uh-oh, probably my first squib," and I was right. The bullet was sitting in the bore just past the chamber. The entire bullet was into the rifling and no amount of smacking on a dowel down the bore would budge it. I did check to make sure that I didn't have two rounds stacked on each other.

So what caused this squib? I'm hoping that I just somehow managed to throw a zero-charge into that case, but I'm worried about the carbon fouling. I want to shoot more of these loads, but I don't want to wreck any more barrels. Is the carbon fouling from the previous round, or did the case not seal in the chamber when this round was fired? I heard NO SOUND AT ALL except the click of the trigger and firing pin, so I'm guessing it was a zero powder charge. I weighed the rest of my 12 grain cartridges and they all have a 12 grain charge, at least nominally.

So what's the verdict? Did I miss the charge, or was there some other, more insidious, problem?
 
The only loads I find listed have a 115g bullet as the heaviest bullet and a minimum charge of 22g of H322.
WHERE DID YOU GET THE DATA YOU ARE USING ???
 
That is SOME experimenting you have going on there:eek:. What are you working on? I am amazed that any of those cycled the bolt in the first place. With a load this below min, and a bullet this above max, it is anyone's guess. I would think the excessive soot is probably from the case not expanding enough to create a good gas seal and getting blow back.
 
I like these kinds of questions!




Watch me hit this one out of the park!















What caused your first "squib"?

















Not enough power to get the bullet to exit!




















I love it when it is this easy!

All kidding aside, there is a reason that there is a minimum set of data for each and every powder, friend. If you are trying to make a subsonic round so the silencer works better, use a different powder. I have a friend, it is with a 223 though, that uses Trail Boss pistol powder to get his done. They don't cycle the bolt though, but he doesn't care. All that can be heard is a "pffffffft". Pretty cool.

All powder has a minimum pressure where they will work reliably. Get outside of that range and you cannot know what will happen until you try. Most of the time on the bottom end you will have a squib, just like you did, on the other end, catastrophic things can happen.

The reason you had a squib is because you expected 12gr of a very slow powder to burn enough to have a heavy bullet exit a long barrel. No equipment problem, no missed load, you simply had limited knowledge about how powders work.

The reason you had carbon on the outside of the case is because there wasn't even enough pressure in it to have it obturate (seal off) in the chamber.

This is the reason that Hodgdon has had the warning on H110 for more years than I can count that says something to the affect: "Do not reduce maximum loads given when using this powder."

Hopefully it wasn't arrogance that drove you to do something like this. Couple that with reloading and it is a VERY dangerous combination.
 
Exactly.

The powder was forward against the bullet vs back against the primer. Try it and prove it. Easy to duplicate. I do powder forward testing a lot with pistol calibers, but normally it is not needed with rifle as the case is mostly full.

Yep, try Trail Boss.
 
Not enough power to get the bullet to exit!

I'm not convinced that this is true. If you read the Lee Modern Reloading manual you will find a listing of loads for different calibers that seem too low as well, but that are not. For example, using the same powder I'm using, with a 180 grain bullet, the Lee manual lists a load for .308 that uses 18 grains of H322. This is in a much larger case than the 6.8, so my loads have similar empty space with my 12 grain charge.

Lee lists these loads for cast bullets, but then makes the following two statements:

... these numbers are calculated from loads tested by the powder supplier with jacketed bullets.

and
A bullet that is too strong usually will shoot well.

You claim that:

The reason you had a squib is because you expected 12gr of a very slow powder to burn enough to have a heavy bullet exit a long barrel. No equipment problem, no missed load, you simply had limited knowledge about how powders work.

This is clearly not true from the evidence. The other cartridges with thee same 12 gr of H322 gave me a muzzle velocity of 1100 fps. This particular one didn't even get the bullet all the way out of the chamber. If you would like to explain why a heavy bullet cannot be moved by a slow burning powder, I'd be interested in the explanation. Especially given that the evidence and the Lee reloading manual are both against this claim.

There is a lot of interest in subsonic ammunition that carries energy down range (i.e. a heavy bullet) and that will cycle an AR15 action. There are cartridges that will do this, and they certainly do not use Trail Boss.
 
with a 180 grain bullet, the Lee manual lists a load for .308 that uses 18 grains of H322.
Not in my Lee manual there isn't!

I loaded up 12 grains of H322 with a 160 grain Nosler Accubond for 6.8 SPC.
Shirley, you can't be serious!

You have the wrong powder, and not enough of it, even if you were using cast lead bullets, and not bonded jacketed bullets with very high bore friction.

I'd suggest you stop before you hurt yourself.

The reason for the sooty cases and finally a squib is you are not getting enough pressure to get ball powder like H-322 to light off every time.

rc
 
If you want a subsonic load that carries energy down range and will cycle you are messing with the wrong caliber. You would be way ahead in the game with a 458 socom or 50 beo. Even a 300 whisper would be better than what you are working with.

That being said, do some research on subsonic rifle loads and you will find pistol powders are what work the best most use fast pistol powders but trail boss is a "go to" powder because of it's bulk.

If you think the load you used is fine because of data for some other combination has you convensed, keep using it. The evidence they were using for their conclusion was your stuck bullet.
 
The reason for the sooty cases and finally a squib is you are not getting enough pressure to get ball powder like H-322 to light off every time.

H-322 is not a ball powder.

Not in my Lee manual there isn't!

Modern Reloading, Second Edition, Page 146.

On the other hand, I goofed and wrote "160 grain Nosler Accubond" when I meant "160 grain Nosler Partition." They don't make the Accubond in a 160 grain .270.
If you want a subsonic load that carries energy down range and will cycle you are messing with the wrong caliber.

Why?

The evidence they were using for their conclusion was your stuck bullet.

This may be true, but it may also be that there was no powder in the case. The other cartridges I loaded up worked fine and cycled the action, except for this one. The bullet didn't even begin to travel down the bore. This looks more like a zero-powder problem to me. I do appreciate the info that other folks have given that indicate this may be a problem with too much case volume, but I don't think that's the answer, given the info from my Lee manual.
 
Modern Reloading, Second Edition, Page 146.

On the other hand, I goofed and wrote "160 grain Nosler Accubond" when I meant "160 grain Nosler Partition." They don't make the Accubond in a 160 grain .270.
The Devil is in the Details!
And you missed the most importent detail right there!

What you failed to notice, or failed to understand is:

Page #146 of the Lee Manual is for grease lubed cast lead bullet loads.

You apparently are using Nosler Partitions!!!!

Hell of a difference in bore friction there my friend!

rc
 
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Why?

Because energy is derived from either speed or mass and you take speed out of the equation when you limit yourself to subsonic speeds. That leaves you with mass to play with. A 160 grain bullet won't have the same energy at the same speed as a 220 grain from a whisper and nothing compared to a 600 grain from a socom.
 
So what caused this squib?

If there was unburned powder in the case, you would have noticed it when you removed the case. It would have made a mess in the action of your rifle.

If the squib had no powder, there would be no debris in the chamber and the primer has enough oomph to get the bullet into the rifling.

You did not describe your loading process, but empty cases and double charged cases are a serious problem with reloaders and can happen. Most reloaders develop a method to check cases after charging. For progressive presses, the manufacturers have designed powder "cop" dies to tell the operator if there is the proper level of powder in the case.
 
He's using Nosler Partition bullets in a 6.8 SPC, with load data he guessed at from a .308 Winchester cast bullet minimum starting load.

Had he double charged it, it would have been much closer to a 6.8 SPC starting load with Nosler bullets.

That right there is his Freeken Problem!!!

rc
 
That right there is his Freeken Problem!!!

rc

rc,
I respectfully disagree. His problem is that he thinks he can do things that have been proven to be failures over and over again and not suffer the same kinds of results.
(Not sure who it was that said this but it does ring true: "Being crazy is when you keep doing the same things and expect different results.")

carnaby,
Listen, you may fall from a roof once without any problems too. Try to repeat it too often and you may come away with a broken bone.

Too light of loads with certain powders, lead to squibs, period. One reason is inconsistency of ignition. You may get away with it once, but don't try it twice.

But, hey, I'm sure you will figure it out on your own. Sorry for butting in. :rolleyes:
 
I'm not convinced that this is true. If you read the Lee Modern Reloading manual you will find a listing of loads for different calibers that seem too low as well, but that are not. For example, using the same powder I'm using, with a 180 grain bullet, the Lee manual lists a load for .308 that uses 18 grains of H322. This is in a much larger case than the 6.8, so my loads have similar empty space with my 12 grain charge.

Lee lists these loads for cast bullets, but then makes the following two statements:



and


You claim that:



This is clearly not true from the evidence. The other cartridges with thee same 12 gr of H322 gave me a muzzle velocity of 1100 fps. This particular one didn't even get the bullet all the way out of the chamber. If you would like to explain why a heavy bullet cannot be moved by a slow burning powder, I'd be interested in the explanation. Especially given that the evidence and the Lee reloading manual are both against this claim.

There is a lot of interest in subsonic ammunition that carries energy down range (i.e. a heavy bullet) and that will cycle an AR15 action. There are cartridges that will do this, and they certainly do not use Trail Boss.
Hmmm. Did you want an answer or...
 
He's using Nosler Partition bullets in a 6.8 SPC, with load data he guessed at from a .308 Winchester cast bullet minimum starting load.

The Lee manual states explicitly that these loads were tested by the powder mfg with jacketed bullets. Are you saying that the fine folks at Hodgdon are fools and know less than you about reloading?
 
You did not describe your loading process, but empty cases and double charged cases are a serious problem with reloaders and can happen.

Good point. I loaded these on a single stage press. I loaded 5 rounds at a time, holding the cases in a RCBS shell holder. Charge one case, move to the next, charge it, repeat until all five cases charged. Press the bullet for each one till they're all done. Crimp. Mark. Done.

I'm thinking the next time that I'll hand meter each powder charge, weigh each with my digital scale, fill the case, and seat the bullet, all in one go. With a charge this light, it's possible to throw a charge that's significantly lighter than desired, which could mess things up as I've seen.
 
I'm saying Hodgdon, in thier wildest dreams, never said you could use 18.0 grains of H-322 powder in a .308 Win with a Nosler Partition bullet.

In fact, the Hodgdon manuals I have don't list any powder charge, with any powder, even close to that low with any jacketed bullet.

What the Lee intro says is, "Hodgdon supplied the raw database for the loads listed, but also did pressure tests with my (Lee) data".

The Lee data is for Lead Cast Bullets, just as it says at the top of every page in that section of the book.

There is NO data, on any of the pages in Chapter 10 for Jacketed bullets, or Nosler Partition bullets especially.

The whole chapter is about cast lead, grease lubed bullets!!!

rc
 
It does appear that you have managed to use cast bullet starting loads with jacketed bullets, and then pieced together some unrelated sentence fragments to show that Lee endorses the practice. That's your call and you seem to have already answered your own question.

But what all this makes me wonder is...why? Even if the squib was from no powder, you have found a load that will not cycle the action and keyholes on the target. Why would you want to load more of that load?
 
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