Problem with W296 powder

[the_mad_rshn]

Hi all,

I am having a really strange problem with 2 bullet waits. 230gr and 200gr. Both are jacketed. The problem is that the primer goes off, but there is no ignition. There is enough pressure to push the bullet out of the case and jam it in the barrel maybe ¼” in. When I was shooting the 230gr bullet I had hang fire in a few instances instead. When I carefully extracted the unfired case and examined the powder I noticed that the powder at the top looks normal. But the powder at the bottom feels slightly compressed and also is brown-yellow (dirty yellow) in color. Please see the attached picture. First I thought I might have my cases contaminated with the Lyman spray case lube, but then I tumbled them and started using Lee’s case lube paste, which does not harm gun powder at all. I opened a new can of W296, but the same problem happened today. This past Friday I loaded a 300gr XTP bullet using the powder from the same can and there was no problem. Not even once. So that confirmed my suspicion about the Lyman lube contaminating my powder, but today’s experience totally destroyed that theory. Unfortunately I do not have different primers so I cannot role them out. I use CCI small rifle primers.
Can you please tell me if you have seen this problem before and if you can tell me what the cause of this is?

Thank you so much.
Cheers,
Mad

P.S. The powder fills the case almost to the bottom of the seated bullet, however it is not compressed and if I shake the cartridge it actually makes the powder-shaking noise.

[wildcatter]

Hi all,

I am having a really strange problem with 2 bullet waits. 230gr and 200gr. Both are jacketed. The problem is that the primer goes off, but there is no ignition. There is enough pressure to push the bullet out of the case and jam it in the barrel maybe ¼” in. When I was shooting the 230gr bullet I had hang fire in a few instances instead. When I carefully extracted the unfired case and examined the powder I noticed that the powder at the top looks normal. But the powder at the bottom feels slightly compressed and also is brown-yellow (dirty yellow) in color. Please see the attached picture. First I thought I might have my cases contaminated with the Lyman spray case lube, but then I tumbled them and started using Lee’s case lube paste, which does not harm gun powder at all. I opened a new can of W296, but the same problem happened today. This past Friday I loaded a 300gr XTP bullet using the powder from the same can and there was no problem. Not even once. So that confirmed my suspicion about the Lyman lube contaminating my powder, but today’s experience totally destroyed that theory. Unfortunately I do not have different primers so I cannot role them out. I use CCI small rifle primers.
Can you please tell me if you have seen this problem before and if you can tell me what the cause of this is?

Thank you so much.
Cheers,
Mad

P.S. The powder fills the case almost to the bottom of the seated bullet, however it is not compressed and if I shake the cartridge it actually makes the powder-shaking noise.

[ http://i39.photobucket.com/albums/e198/the_mad_rshn/IMG00099-20091018-1450.jpg ]

Ok, first thing, STOP!! Do not shoot this any more until we work this out. I personally have never seen powder that looked like that. Let me think about it. Any of you other guys have a clue here. Was that brown stuff in a clumped mass, almost like a gob of gunk, semi-solid, but when probed, the gob fell apart? I have my suspicious, can you tell us more about the load?

[pitted bore]

Mad-
What you have reported is the typical bad behavior of light bullets in the 450B, and is predictable. Check out the thread in the General Reloading forum that was started on 7 Aug 09 by demo-450, titled "Trying 200 Grain load Saturday".

Here's my working hypothesis that I haven't seen contradicted here yet. When the primer ignites, it does a couple of things; it starts the powder burning, and it also creates enough pressure in the case to drive the bullet out of the case into the lands. The usual situation is that in fractional milliseconds, the powder ignites and builds up enough pressure to cause the powder to burn quickly and completely. That's why smokeless powder is called progressive burning - with more pressure it burns faster to create more pressure, etc., with positive feedback until the powder is all consumed, and all before the bullet is very far out of the case.

The presssure from the primer, coupled with the pressure from the burning powder, causes the bullet to exit the case. When it does so, the combustion chamber is enlarged, which tends to cause pressure to be reduced. Unless the powder is really burning and into its positive feedback cycle, the reduction in pressure can cause the powder to stop its burn.

The hangfires experienced by those of us who've messed with light bullets are the result of the burn being interrupted. The pressure drops as the primer pushes the bullet and some of the powder out of the case, so that ignition is incomplete. However, since the bullet is jammed into the lands, there may be sufficient pressure redeveloping to cause the powder to recommence burning, and then the rifle goes bang.

In the 450B, with bullets weighing 240 or more grains, when the primer ignites, there's sufficient inertia of the heavy bullet so the powder can start and complete its progressive burn successfully before the bullet is very far out of the case. With lighter bullets, this doesn't happen. What you have observed is the result of failure to get the powder burning due to low pressure.

The yellow color you see is the color of 296 and most smokeless powder before graphite and other surface coatings are applied to the grains. I'm not sure what causes the graphite to disappear.

The light bullets are in general not compatible with relatively slower powders like 296 and its H110 twin, or AA1680. Lil'Gun will likely work better than 296 with 200 grain bullets, because in the 450B it's a smidge faster. However, you're on you own for loads. Hornady probably will not produce any loading data for light bullets.

I learned about this while working with 185-grain bullets. You can read the saga on this forum. It's up to six chapters already.

--Bob

[wildcatter]

Except Doc, he was shooting 230gr bullets as well. Though I agree with you, 296 has always been a friend of mine. I have untold tens of thousands of rounds using it and using it with 200/185gr bullets too. It looks to me to be a horror-ably over compressed load, except, he states that he can hear the powder moving when he shakes a loaded case.

To maybe go down the Doc's path, Mad, do you have some lil-Gun or something in that burn rate area? Even Blue dot would be good, I've used it allot for Arctic Shooting.

[pitted bore]

Ok, first thing, STOP!! Do not shoot this any more until we work this out. I personally have never seen powder that looked like that. Let me think about it. Any of you other guys have a clue here. Was that brown stuff in a clumped mass, almost like a gob of gunk, semi-solid, but when probed, the gob fell apart? I have my suspicious, can you tell us more about the load?

T-
I'll attach a photo that shows the same thing that Mad observed. This happened in 2007 with a long Berthier rifle in 8mm Lebel. (The phenomenon is not unique to the Lebel - it just happened to be the rifle I was shooting when it happened.)

The rifle went "click" instead of "bang", and I noticed some smoke curling out of the action. I waited a bit, opened te action, and the case came out normally. It was sooted. Some granules of powder (I think it was RL15) came out with the case. Looking down through the barrel, all was dark. I took the rifle home and found the bullet was jammed into the lands. From the muzzle I knocked the bullet back into the chamber (which is why the flattened tip in the photo), and a cylindrical mass of aggregated powder came out with the bullet. The powder mass had obviously had been forced into the barrel. Some of the powder granules were yellow, and some were partly yellow. The mass was held together with a light coating of thin tar. Initially the tar was damp, but it dried in the air.

I think the cause of the event was a long, smooth throat in the Lebel. I believe the sequence was what I wrote above: The force of the primer drove the bullet out of the case and down the barrel before the powder had a chance to ignite and bulid up pressure. The powder was blown out of the case along with the bullet.

Some persons have written that similar things might be happening in the case of the infamous "Secondary Explosion Effect", which caused some rifles to blow up in the 1960s. In the instance of my Lebel adventure, what might have produced bad trouble would have been ignition of the powder after it entered the barrel. In that case, the bullet would have been acting as a barrel blockage, with a resultant big increase in pressure.

So, you're absolutely right, Mad should STOP trying 296. He may not be getting a sufficient crimp to hold the bullet in for the fractional amount of time needed to build up a good burn, or his lot of 296 might be a little bit harder to ignite than other lots, etc., etc. There are many possibilities that might produce what he's seeing.

Feel free to tell me where I've gone wrong in my ideas.

--Bob

[wildcatter]

Doc, day ain't no-way I going to tell you, you are wrong, because I think your hypotheses is exactly right. I'm just scratching my head, cause of my long standing experience with 296. The events you, so correctly describe, are usually observed with really slow powders, none of them are pistol powders and of course 296 is a pistol powder and not even a particularly slow one either, really only medium-slow.

But I've forwarded the data and picture over to a Super-Duper, for real, High-End, Expert, in these matters. I think, however, that ol' Doc here is going to be found the more correct. I concur with him, so far, and he gives credence to my original suspicions, I just don't want to believe it.

If the Doc and I are right about this, it is dog-gone lucky he did not experience Detonation, blowing the gun apart!

MAD? Were you using your side crimp? And we really do need more data about the load, most importantly, how much powder, what kind of bullets, and how deep did you seat them etc.

TAKE NOTE, ALL YE HANDLOADERS!! This is serious business and SAFETY is your biggest concern and YOUR RESPONSIBILITY ALONE !!

[pitted bore]

Mad-
Answers to a couple more questions may help in deciphering what's happening. Wildcatter's question about the crimp is really important.

If you used the Hornady taper crimp die, what was the diameter of the case mouth after crimping? If it's not sufficiently crimped, then the bullet can exit the case too easily. If it's really scrunched, then possibly the bullet has been swaged by the die to a smaller diameter so it doesn't engage the lands immediately.

What are the diameters of the bullets you are using? I suspect they are nominally 0.451, but if they are a trifle smaller, it may make a difference in firmness of crimp or immediate engagement with the rifling.

Did any of the 230-grain bullets get hung up in the barrel, or only the 200 grainers? Your original post indicated that you had some hang-fires with the 230s, but it wasn't clear if that was the only problem with them.

Since I'm not really expert with the ARs, I may be guessing wrong here, but have you checked for bullet movement when chambering? Some of the others on the forum have noted that bullets may move forward from the case when the bolt slams the cartridges into the chamber. If this is happening with your loads, then it might help to explain your observations, because you'd be starting from a pre-expanded lower-pressure combustion space.

Wildcatter's safety warnings are on the mark.

--Bob

[wildcatter]

Another thought here...Hornady uses a 297 product which is slightly, very slightly, slower than our 296, of course they are using 250 grainers..

[the_mad_rshn]

Gents,

Thanks so much. From more research on the net and posting a couple of other places it does look like the problem is a known one with the 296 and H-110 powders. Here are some of the answers.

Today the load was between 42.5gr and 44.5gr in increments of .5gr 5 rounds each weight. I started with the lightest so I can observe if the pressure signs show with the increased loads. I went through only 5 rounds of 42.5. First 2 fired and the rest did "click-noting". I seated the 200gr XTPs to 2.05". They are .451" in diameter with no crimping grove, but I do use a pretty firm Lee Factory crimp from my modified 45-70 die. The problem with these bullets is that they are short and the crimp is low so they basically are being held by the crimp only by their base. I wish I cut the collet only .5" instead of .55". I cannot push the bullet in manually, but I cannot tell you how difficult it is to pull it out because of the latter.
The 230gr bullets were Winchester .451". At the time I used unmodified Lee's FC for crimping. To work with 450BM I would just shim it in a way, but the crimp was still very week. Some of the rounds would have hang-fire others would not fire at all with the bullet getting stock in the barrel right at after the chamber, just like today. The load was something like 41gr of 296.
Some time last a week before last I was also shooting 300gr and 405gr made from wheel weights in front of W296 (forgot the numbers). I sized them at .454 and crimped the same way as the 230 grainers. They all ignite very well without a glitch.
I tried shooting some 2400 and BlueDot with my cast loads and neither had the problem like that.

Anyway. Thanks a lot all. I hope we can get to the truth

Cheers,
Mad

P.S. I did shoot 110 and 296 in many other calibers - .357, 44 Mag, 454 Casull and 45LC but never I had this problem before.

[Al in Mi]

I had a couple of simular things happen with 296 back in my 454 Casull days. One of the guru's back then, suggested compression of the powder, a heavy seperate crimp and I've had no problems since with 296.