What Caused My Squib?


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carnaby
December 7, 2010, 12:18 AM
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?

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Blackrock
December 7, 2010, 06:11 AM
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 ???

68wj
December 7, 2010, 06:33 AM
That is SOME experimenting you have going on there:o. 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.

Skip_a_roo
December 7, 2010, 07:02 AM
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.

Fleet
December 7, 2010, 07:08 AM
The powder may not have been close enough to the primer to ignite.

Walkalong
December 7, 2010, 09:53 AM
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.

243winxb
December 7, 2010, 10:30 AM
What Skip a roo said http://castboolits.gunloads.com/images/smilies/drink.gif

carnaby
December 7, 2010, 11:18 AM
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.

Skip_a_roo
December 7, 2010, 11:25 AM
Hopefully it wasn't arrogance that drove you to do something like this. Couple that with reloading and it is a VERY dangerous combination.

Well, so much for that! :rolleyes:

rcmodel
December 7, 2010, 11:35 AM
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

jmorris
December 7, 2010, 11:43 AM
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.

carnaby
December 7, 2010, 12:48 PM
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.

rcmodel
December 7, 2010, 12:57 PM
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

jmorris
December 7, 2010, 01:35 PM
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.

cfullgraf
December 7, 2010, 02:08 PM
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.

rcmodel
December 7, 2010, 02:17 PM
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

Skip_a_roo
December 7, 2010, 02:31 PM
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:

mdi
December 7, 2010, 02:50 PM
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...

carnaby
December 7, 2010, 03:03 PM
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?

carnaby
December 7, 2010, 03:06 PM
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.

rcmodel
December 7, 2010, 03:17 PM
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

Walkalong
December 7, 2010, 04:51 PM
He's not listening rc.

Skip_a_roo
December 7, 2010, 05:41 PM
I have this mental picture:

http://i142.photobucket.com/albums/r115/Sackettwannabe/dontwanttohearit.jpg

griz
December 7, 2010, 05:46 PM
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?

snuffy
December 7, 2010, 06:54 PM
And this guy builds barrels and AR uppers?

Bison Armory 6.8 SPC Specialists

You come here asking why you had a squib, then argue with us when we tell you you're wrong? You would be the last place I'd go for an upper with an attitude like that!

http://www.thehighroad.org/showthread.php?p=6911435#post6911435

Interpolating loading data is common place. But not from an entirely different caliber and type of bullet!:what:

carnaby
December 7, 2010, 06:56 PM
...and then pieced together some unrelated sentence fragments to show that Lee endorses the practice.

Lee certainly did not endorse this practice. I'm saying that Hodgdon fired these loads with jacketed bullets, which is all the manual states. Make whatever you want of that.

Look, I wasn't looking for opinions on whether or not I should be doing this, that's what my mom is for. I was only asking for opinions on the evidence, and if it looked like this was a squib due to a complete lack of powder or if the powder failed to ignite because of the excessive case volume etc.

Really, I didn't ask for any other opinions. As long as I'm not risking detonation with a low charge, then I don't care if this is a bad idea, and I don't care if I ruin a bunch of barrels. Trust me, I have more than enough to spare. As long as I'm checking after each shot for a squib, then there's no other danger involved.

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?

Good question! The answer is that it's a secret, but if you knew the answer, you'd understand. If I had gobs of cash lying around to do the testing the right way, I wouldn't be doing this. On the other hand, shooting subsonic loads that cycle the action is fun. And I was getting subsonic loads to cycle the action, just not that particular load.

243winxb
December 7, 2010, 06:58 PM
http://68forums.com/forums/content.phpCAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

I am currently loading the 160 grain Nosler Partition, and the 150 grain Sierra Game King, and with both 4198 and reloder 7, I have them cycling but not locking the bolt back. I am using a carbine gas, but I also have a pistol gas barrel on the way.:confused:

http://68forums.com/forums/showthread.php?16931-Subsonic-Loads-That-Cycle These are 130gr round nose bullets. This video was done with the IMR4759 powder 10.5 grains. :uhoh:

carnaby
December 7, 2010, 07:01 PM
You come here asking why you had a squib, then argue with us when we tell you you're wrong?

I appreciate all the help identifying whether or not the squib was likely to have been due to a missing charge or not! I wasn't asking for opinions about why 6.8 subsonic is no good, or whether or not I should be trying these loads in the first place. People were arguing for all sorts of things that I don't care about and didn't ask about.

243winxb
December 7, 2010, 07:02 PM
Maybe a faster powder?? Burn rate chat > http://www.hodgdon.com/burn-rate.html Good luck, be safe.

Walkalong
December 7, 2010, 07:27 PM
I still say Trail Boss is a viable option. Certainly one he should try.

I also agree with 243winxb, try a fast pistol powder...very carefully, and always have it powder back.

Ask me what Blue Dot (powder forward) will do in .22 Hornet. :o

Trail Boss. Very very bulky. Good stuff for reduced loads in rifle calibers. Others to try are AA-5744 or SR-4759 which are designed for reduced rifle loads, but they may give more velocity that you are looking for.

Skip_a_roo
December 7, 2010, 07:54 PM
On the same page as quoted by the OP, it has this caveat. I found this very interesting too:
"Italics = Calculated pressures may be less accurate due to the large reduction" The 308 data used is in italics.


The op's charge is at the bottom of the published data for a completely different bullet. It just seems to make so much sense that there isn't enough energy stored in this powder/cartridge combination to reliably get the desired results.

In the op's "correlation" to the 308 he failed to notice that a 1gr increase at the bottom level of the data used only increased the velocity by 30fps! 2gr increased a whopping 70fps!

The silencer will still be just as quiet and the neighbor's dog or cat or whatever will still be just as dead, sideways bullet and all.



Sticking to your 12gr "guns" is going to prove fruitless unless stuck bullets is your goal! ;)

howlnmad
December 7, 2010, 08:29 PM
Easy answer.

Not enough bang bang kernels in the boom boom room. :D

Skip_a_roo
December 7, 2010, 09:17 PM
Easy answer.

Not enough bang bang kernels in the boom boom room. :D

http://i142.photobucket.com/albums/r115/Sackettwannabe/thSMILEYROLLINGONFLOORSMALL.gif


PRICELESS! Permission to use this in the future! :)

243winxb
December 7, 2010, 10:12 PM
CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.
I still say Trail Boss is a viable option. Certainly one he should try.

Trail Boss looks a little faster than Alliant's Unique. .:confused: Loading 7.0gr of Unique to maybe a maximum of 10.0gr. with a 160 grain Nosler Accubond in his 6.8 SPC might work for 1000fps. Thats my best guess. :confused:

jmorris
December 7, 2010, 10:13 PM
One statement you made was This may be true, but it may also be that there was no powder in the case.

Then you say As long as I'm checking after each shot for a squib

The answers you received as to “why” were assuming you were checking to make sure you had powder as much as you were checking if bullets were stuck in the barrel.

You certainly knew before you started a new thread that if you had zero powder in the case, that would have been the cause of your squib…right?

ArchAngelCD
December 7, 2010, 11:43 PM
Why are you guys continuing to argue (I mean reason) with this person?
It's obvious he disagrees with everything said here even though he was the one who produced a squib load, not us. :rolleyes:

May I suggest you leave him to his own devices now that he's been warned. Your job is more than done here, it's all up to him now not to hurt himself or someone near him. :uhoh:

howlnmad
December 8, 2010, 12:26 AM
http://i142.photobucket.com/albums/r115/Sackettwannabe/thSMILEYROLLINGONFLOORSMALL.gif


PRICELESS! Permission to use this in the future! :)
You go ahead and use it anytime you want. I'm glad somebody thought it humorus.

carnaby
December 8, 2010, 10:34 AM
You certainly knew before you started a new thread that if you had zero powder in the case, that would have been the cause of your squib…right?

Yes, obviously. I was asking if anyone, based on the evidence, could tell if this was a zero powder issue or if there was powder and I got the squib anyway. I'm inclined to think that there was powder in the case and that I got the squib for some other reason. The soot on the case is the giveaway, I think, but it may have been a much smaller charge than I intended. There's no way to know, I guess.

As to the nay-sayers of using loads such as these, the new AAC Blackout (http://300aacblackout.com/) uses a very similar load. A 220 grain bullet over 11.2 grains of AA1680 in a .223 Rem case necked up to .30 cal. AA1680 is only a little faster than H322, and has higher density so the powder volume will be less.

snuffy
December 8, 2010, 11:18 AM
All the criticism aside, I'd like to see you achieve your goal. Whatever it is. The 6.8 SPC is a 30 Remington case shortened, necked down and blown out for maximum powder capacity. As such, it has much more case capacity than a .223. So you're comparing apples to horse apples. If you insist on using H-322, you're going to have to use MORE of it. If that results in supersonic velocity, then you'll HAVE to use a faster powder! That's as plain as I can make it.

To say nothing about a 160 nosler accubond @ 1200 fps. It won't expand at all, so it'll be like shooting a FMJ. If all you want is a hole in something, well that it will do. (If it will stabilize)! A keyholing, unstabilized bullet will NOT be accurate,,, at all! So, am I wasting my time even trying to help?

carnaby
December 8, 2010, 11:52 AM
Thanks snuffy.

I'm looking at using AA1680 which is faster than H322, or SR4759 which is both faster and significantly bulkier. Yes, I realize that the .223 case necked up using a .30 cal bullet isn't the same as what I'm doing, as the case capacity for the 300 BLK is less than mine.

True, the 160 Partition won't expand at subsonic velocity, but there's no alternative that I know of... nobody else makes a heavy .270 bullet.

snuffy
December 8, 2010, 12:35 PM
I'm looking at using AA1680 which is faster than H322, or SR4759 which is both faster and significantly bulkier.

NOW you're cooking with gas! The 4759 would give you a nearly full, or completely full case, but still be subsonic. I can't even begin to offer loading data, I doubt that any exists. The pressure curve drops off fast with 4759, so your port pressure might be too low to work the action.

Why are you stuck on the 160, and is it the accubond, or the partition. Your OP says accubond. There's a bunch of 150 grain bullets out there, if it were me, I'd go with the 150 SST from Hornaday, or the Nosler 150 ballistic tip. Both will open/expand at much lower velocities, and you're only giving up 10 grains of bullet mass.

You MAY have to go with the shortest 150 grainer out there to achieve both sub-sonic velocities AND stability. It's not just weight that's in the formula for stability, it's also length. That leaves out plastic tipped, boat tail bullets. Speer makes what they call a "deep curl" bullet. It's a plated bullet like the Federal fusion, since they both have the same corporate parent. Speer's gold-dot technology was used to produce the Federal fusion bullet. It is a flat based exposed lead point bullet. If it would expand @ 1200 FPS is anybodies guess.

Is 1-11 the standard twist for 6.8? Does anybody make a faster twist? You may HAVE to go that route.

carnaby
December 8, 2010, 01:33 PM
Your OP says accubond.

Right, I'm a doofus! I meant Partition.

Is 1-11 the standard twist for 6.8? Does anybody make a faster twist? You may HAVE to go that route.

Model 1 sells 6.8 with 1/9.5 twist, which may stabilize the 150/160. I understand all about twist and stability, that's not an issue for me at the moment.

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