Well, let's take a look at what Ross says in the article. Here is the paragraph from the Handloader October/November '02 issue starting on P. 38. The paragraph is on P. 43. The article is entitled Loading the .500 Express, Extreme black-powder performance by Ross Seyfried
It does not say, .500 Nitro Express.
I'd like to thank Bob Cuyler for providing me a copy of the article.

"The actual load to make the rifles shoot to perfection is stunningly simple. One uses the correct bullet (this may take a little experimentation) driven by 40 to 60 percent of the original black-powder weight of IMR or Hodgdon 4198. Primers are standard Large Rifle (not magnum). The other key ingredient is Dacron polyester filler. The material looks like cotton and come in a plastic bag to use to use as teddy-bear stuffing. In a .500x3, use 13 grains. Yes, this a big ball and the case is full, That is how it is supposed to work.
I cannot warn too strongly against using any kind of cereal, plastic or foam filler. While a little foam worm looks innocent enough, I know of two very fine double rifle that have been ruined with foam filler."

Once again let's look at the exact reference again. .The other key ingredient is Dacron polyester filler. The material looks like cotton and come in a plastic bag to use to use as teddy-bear stuffing. In a .500x3, use 13 grains. Yes, this a big ball and the case is full, That is how it is supposed to work.
I cannot warn too strongly against using any kind of cereal, plastic or foam filler. While a little foam worm looks innocent enough, I know of two very fine double rifle that have been ruined with foam filler."

That is all this article says about Dacron polyester filler and foam or plastic fillers.

From the above it looks like Ross is saying to use the Dacron polyester. Looks like he highly reccomends the Dacron filler but not the foam. This article deals with reloading a black-powder round.

So, from what I have read I have no reason not to use the Dacron polyester filler as Ross wrote in his Article Reloading the Nitro Expressin the December/January '2000 issue of Handloader magazine. I see no reason not to use the Dacron polyester filler in my 450/400 3 inch. I see no reason not to use the Dacron poly filler in any Nitro Express reloading using RL-15.

I'd stay away from the foam plugs reloading a black-powder round.

That is all this article says about Dacron polyester filler and foam or plastic fillers.

Hope this helps in our quest to reload our Nitro Express rounds!

[ 12-23-2002, 00:51: Message edited by: Rusty ]

Type-o on my part. I have edited my original post.

If you would like a copy of the 2000 article I will email it to you.

Oops, sorry Mickey I see you don't post an email addy.

Rusty

[ 12-23-2002, 01:06: Message edited by: Rusty ]

As to why the foam plug is dangerous as a filler: Maybe Ross doesn't know himself?

Two ruined double rifles that he knows of, and both were using foam? Not a very large database.

13 grains of Dacron would probably be equivalent to a one inch or longer foam plug.

Maybe this large amount of foam partially liquifies on the way out and forms a noncompressible hydraulic fluid behind the bullet and does "funny jackhammer things" under pressure just after ignition of the load. Could this ring a chamber or damage a barrel? I dunno. What is actually going on here?

Ross didn't say what kind of damage was done to the two rifles in question.

Is it some kind of chemical corrosion of the bores that cereal and foams cause, but polyester fiber does not, with repeated use?

Not clear at all from this quote.

A 1/2 inch thick foam plug in my 470 NE loads with RL-15 gave super consistent accuracy loads for me. This was polyurethane "packing foam."

Butch Searcy is said to use styrofoam.

I am leery, and will go to the Dacron polyester fiber filler.

Maybe the polyester fiber swabs the nasties out of the bore as it goes, and is resistant enough to melting or burning that it emerges intact from the bore, and cleans it as it goes.

The foam plugs just vanish on combustion.

Mysterious, eh?

Thanks for starting a new thread with the more extensive quote. Tip of the hat to Rusty.

I have recovered foam filler from the RL-15 loads I fired in my 450 No2. I do not remember seeing any signs of melting. The next time I fire some I will take a better look.

You will all recall that I have been using polyolefin (I think) foam filler in my .510-.505 Gibbs, now up to 2350 fps or so with the 700-grain M2 ball. The stuff comes as a 20 foot long cylinder intended to be used as a super-easy caulk substitute from Home Depot. You just slice a plug off the end of the cylinder. None of that cookie-cutter work. This reduced the incidence of hangfires with loads that didn't completely fill the case to zero.

Upon extracting the case, I can sometimes find frazzled-looking, compressed, and maybe half-burned little bits of foam stuck to the mouth of the case. My explanation for this is that the case is just a smidgen shorter than the chamber (good), and that the foam is crushed into a "cup" around the bottom of the boattail, and just a little bit of the foam expands into the gap between the end of the case and the end of the chamber, and the rest of it goes screaming by on the way to the other end of the barrel. A "trap" intended to let the bullet pass and catch anything else might catch some fried foam bits downrange.

My polyolefin (?) plugs do not just vanish upon ignition. I can't find any in the barrel.

I have less confidence in Ross Seyfried's directions for loading large cases than I have had in the past. He instructs us " I cannot warn too strongly against using any kind of cereal, plastic, or foam filler." But AFTER that he details his use of grease and vegetable fiber wads, felt wadding, and the base of a plastic sabot (?), all mentioned in the same article as being introduced into the interior of the case as load components. The logic that permits these other kinds of filler, but not plastic foam, escapes me. It is not one's intent in inserting the material into the case that matters in determining whether or not it is filler, but that it is in the case.

I do not own a double, and I expect I never will own a big-bore double. But if I did, I would be tempted to try IMR5010 in first working up loads with a foam filler, and then when load development was complete, perhaps with a full case and no foam and good regulation. A slightly compressed load only made 2075 fps in my .510-.505 with a 700 grain bullet. I understand the pressure curve is a matter of concern because preessures might be higher farther down the barrel than with other powders, but in the presence of proof marks, I think this is not much of a concern.

Once again, the article deals with loading the .500 Express a black powder round, not a Nitro Express.

There is nothing wrong with using the Dacron polyester filler. It isn't as easy as cutting off a tube of foam or cutting out a plug of foam, but I can recover all of my filler in front of the firing line. They are not burnt. They look like they could be loaded again. I use RL-15 in my Nitro Express double rifle. I will continue to use it.

Rusty
We band of brothers!

Keeping in mind that what little chemistry I have picked up in my life is now more than 25 years old, and unused since, and that I know nearly nothing about double rifles:

It seems to me that the two possible mechanisms by which foam of some kind might damage a double rifle are chemical and mechanical-pressure related.

Ross Seyfried says "I know of two very fine double rifles that have been ruined with foam filler."

I have been wondering if the various plastic foams and fibers have halogens (fluorine, chlorine, etc.)in them, in which case you could perhaps expect barrel corrosion with either fiber or foam without cleaning. B.P of course has sulfur in it, and is hygroscopic and can lead to rusting without removal? It seems to me that appropriate cleaning would reduce the risk of this to zero. In this case it would be the owner and not the foam that had ruined the rifle.

So it seems that the cause is of mechanical, pressure-related nature. Am I right in thinking that with a double rifle in good condition, the action always fails before the barrel(s)? Are the proof pressures fairly moderate for the thickness of the barrel and the quality of the steel, and therefore we may conclude that it is the action that is being most severely or solely tested during the proofing process?

If this is true, then it is the highest pressure that the action can tolerate that is being tested, because the action cannot tell where in the barrel the bullet is, and the highest pressure is reached only just after ignition. One example calculated using some assumptions in the A-Square Manual (p.101)gives peak pressure (presumably for a bolt-action or other strong action!) after just 2.8 inches of bullet travel at 60000 psi.

So if the foam is going to affect pressures to the ruination of a double rifle by means of damaging the action, it will have to do so in the first few inches of travel, because after that the likely magnitude of an increase in pressure that might be caused by the foam will not exceed the previous pressure peak caused by a normal working load composed of powder and no filler? If pressure is the cause, one would expect these ruined rifles to have damaged actions (shot off the face?)or barrels that are ringed or bulged near the action. Damage further down the barrel would not be related to pressure, and one might instead hypothesize an obstruction (bugs, dirt)?

It's worth noting that in the A-Square Manual on p. 81 there are some comments on the use of filler v. slower powder. A-Square reports finding pressure spikes with filler and "...The only safe and reliable way to ensure ignition in a large capacity case is by selecting a slower, bulkier powder to fill the case." A check of the load data shows that a lot of the large double rifle pressure data was obtained with a piezo transducer, so they could indeed have seen pressure spikes which would not have been detectable with a copper crusher system, which tends to average because of the masses of the various parts?

It seems what is needed here is transducer data comparing medium/slow powder with fiber to foam, and slow powder with a full case, loaded to identical velocities. It would be nice if Ross would share the reasoning behind his bias against foam and some other fillers, particularly v. fiber.

Speaking for myself only, I suppose I can add MORE POWDER, or maybe seat the bullet back to use up some of the space and preclude hangfires, but not until after I restock the rifle to make that reasonably comfortable. Prone across the chronograph with no brake has not been a lot of fun. Happily the empty space is already much reduced from the starting loads, and I might already be out of the range where hangfires of noticeable duration might be expected, but there is an encouraging amount left to be filled.

The smoky necks and large case volume and largely unmodified nature of the foam and drop-out-of-the chamber extraction and the currently long barrel (32") and moderate velocity (2350 fps) suggest to me that I am working at pressures of about 45000 psi?

SDS,
I don't know what the problem was. I don't think it was the action failing. I can only offer what the article states and my experience with the Dacron polyester and my nitro express double rifle.

If I had melting plastic going down my bores, I would be concerned about it building up.

Be gald to fax the article to any who haven't read it.

Rusty
We band of brothers!

[ 12-24-2002, 00:05: Message edited by: Rusty ]

FWIW- I believe the phenomenon that has wrecked these guns is Chamber Ringing, not the actions failing. There is a fair amount of data that suggests that chamber Rings ( I have seen three examples of this) are caused by Fillers or wads that leave enough air space in the cartridge, that upon ignition, they rapidly compress the air space producing a localized high pressure spike that expands the metal of the chamber.Think of a very fast moving piston in your case. These rings were only about .002-.003 deep, but were enough that cartridge extraction was extremely difficult. In two of the cases I examined, this chamber ring occured just behind where the bullet was seated. All black powder shooters know not to leave any air space in their guns between the powder and the bullet, however, the use of wads and grease cookies sometimes leaves room for error. Peolple also forget sometimes. Chamber Rings will occur with black powder cartridges like the 45-110/120 unless care is taken to avoid any air space inside the cartridge. This at black powder pressures of about 38Kpsi or less. I am told this problem is worse with bottlenecked cartridges than with Straight cases. I personally have used Dacron fiber for a filler for over 25 years in everything from the 45-110 to the .50 BMG with cast bullets and have not run into any problems. I stuff enough Dacron in each case that there never is a doubt as to the lack of any air space.
The same logic holds true for smokeless cartridges. If you use a filler, make sure there is absolutely no possible air-space that the wad can use as a piston. Personally, I use XMP5744 that works extremely well without a filler in very large cases like the 470NE up to .50BMG and /or find a powder ableit a slow one that fills the case completely. When this is not feasible( and it almost always is) I use dacron fiber as a filler. I should say that there have been some reports of chamber rings even with dacron Fiber, but my guess is these guys didn't add enough and still had an appreciable air volume inside the case. I use enough dacron that the powder charge can't move at all and it actually improves ignition significantly. My chron data on dacron fiber loads often shows std .Deviations in velocity of less than 10 fps,particularily in very large cases.-Rob

Thanks, Rob!

SDS and Robgunbuilder,
Your's are most "enlightening" thoughts. The really light foam is almost all air. 0.5 to 1.0 grain of foam equals 5.0 to 6.0 grains of Dacron fiber filler in some cases.

The light packing foam wads are like nothing is there but air within their lattice work and bubbles. They vanish when fired. The denser foams do not.

A dense foam or a tight packed wad of polyester fiber is the air excluding wad that holds the powder in place without allowing a pneumatic jackhammer to work on the chamber.

I am lucky that I only had the 470 NE with about a half inch of airspace at the top of the powder that I was filling with light foam. No damage to my chambers has been done, and won't be!

THERFORE I AM ENLIGHTENED :

Either a tight wad of Dacron fiber with RL-15 in the NE loads,

OR a full case of H4831 or slower powder with no filler, whatever fills the case best.

These are my choices, and I think I am starting to like the latter better.

The H4831 in a 470 NE will give pressures around 32Kpsi for a 500 grain bullet at 2150fps.

The RL15 with filler goes about 40Kpsi.

I think slow powders damaging modern barrels is a non issue. It relates to antiques with thin barrels.

So I have finally decided to go ahead and use slow powders and full cases with a batch of BELL brass I have. Then I will have to add a couple of grains more powder to get the lighter Norma brass loads up to snuff.

Gee, I feel like I have learned something!

I wonder if the two double rifles Ross Seyfried says were ruined were DAMASCUS BARRELS? If so that might explain a lot.

DaggaRon- I use quickload alot these days to find loads that are near 100%to 102% case capacity. Particularily with DGR's. This way the powder column acts as a bullet support so that they do not set-back on firing recoil. Of course crimping helps, but a full load of powder is even better.
With respect to Dacron fiber, I don't bother weighing it, I just stuff in enough to fit to the case mouth and to definately cause compression when the bullet is seated and crimped. Using this technique, my velocity SD.'s have dropped and I've never experienced a chamber ring even in double rifles.-Rob

RGB, I am fascinated by the phenomenon of chamber rings. I can imagine something like that occurring with a barrel obstruction (best observed with a stuck bullet with a partially burned squib charge behind it and then another round fired?), but I had never thought of it happening inside a case. Do you suppose the mechanism is properly described as an advancing shock wave that when it is obstructed by the very slowly accelerating bullet, goes radially outward? Where can I read about this? Because this is associated with air space inside the case, do you suppose this is caused by poor ignition, followed by detonation instead of combustion, instead of the air volume?

It might be easier to ring a chamber with ball powder than extruded powder: if you get poor ignition, you'll burn the retardant coating off the ball powder, and then when it goes, some of the powder will be as fast as pistol powder? It might be easier to ring a chamber by partially filling a case (with ball powder?), pointing the rifle downward to get the powder to the front of the case, and then discharging it? All the powder will get hot, the rearmost portion will burn, and the powder at the front will detonate? Or maybe slightly downward so there is free surface all the way to the front of the case?

Your low SDs suggest that it is not always true that filler produces pressure spikes.

Daggaron, I am not embarrassed at all to say that you should trust anything RGB says at least fifty times as much as me. I try really hard to report only what I have observed, but I find trying to figure out the mechanisms fascinating. I have been adhering to the "compressed load" policy in the A-Square Manual, so I always use more (dense) foam than there is space between the bullet and the powder. It is not possible to distinguish a hangfire, either at the time or when calmly reviewing the video later.

Maybe the "light foam v. dense foam" issue is like crimping the case mouth on the bullet to get lower SDs because the powder can't move around and burns more consistently?

During the time we have been worrying about this, and I mean the last few months, I have been trying to figure out why putting foam behind the bullet could be like something other than only making the bullet 5 or 10 grains heavier. If we grant that Ross Seyfried is right, it would have to be true (?) that putting the foam in the case makes the case smaller, and then it would be like putting a .460 Wby. load in a .458 Win case. Since we do not see overpressure signs, the powder must "believe" it is in a full-size case, and so the issue must be other than that? My amateur efforts with "dense" foam are not turning up problems, but it could be that RGB's case ringing IS occurring with light loads (of ball powder?) and "light foam", which is not holding the powder properly against the flash hole and leading to a detonation phenomenon?

I believe I have read that "smokeless powder for small arms" is supposed to burn, but that BP actually explodes? This lends some credence to the smokeless powder light load detonation idea?

NE 450 No. 2, your comment with regard to Damascus barrels is most apropos. In the current January 2003 issue of Rifle Magazine, Ross Seyfried returns to the "failed Nosler Partition" controversy, and says he is STILL waiting for anyone to produce either a Nosler Partition with a ruptured (rear) jacket or a failed Damascus barrel, in either case under normal use, the latter challenge having stood unanswered for a number of years now. I don't have the magazine in front of me right now, so please don't hold me to this too tightly.

So, SDS which of your reloadings do you use a filler in? The 510-505 Gibbs? Please tell me more about this round. You shoot Woodleighs bullets? I guess it is impressive on game?

[ 12-24-2002, 05:13: Message edited by: Rusty ]

Before I begain loading for my 450 No2 I did as much research as I could about chamber ringing using poly or kapok as a filler. There have been many reports written by the people who "rung" their chambers. These were first hand reports not "I heard" reports. There was always one common factor, only the smallest amount of filler was used, usually pressed down on a small amount of powder to hold it against the primer. This is where I got the Idea that it might be caused by a compression of air inside the case at the base of the bullet, where some had said their chamber was ringed. I really do not see how this small anount of compressed air could ring a chamber of modern rifles but something is doing it. I do know that I have fired several hundred rounds in my 450 No2 with enough poly inside to be compressed by the bullet. These loads have used 350gr. 480gr. and 500gr. with 3031 and 480 and 500gr. with IMR 4831. I have fired some loads with RL-15 and "foam" filler with no problems. I have the "foam" loads on hold until I can find out more about Ross Seyfried's statement. Graeme Wright in Australia is probably one of the most knowledgeable people with regard to shooting double rifles. Does any of our Aussie members know how to contact him? He can probably be reached through the BIG GAME RIFLE CLUB. I always weighed the poly filler for every case. The foam is easier to use, but not if there is any chance of rifle damage. I have sent an e-mail to Rifle Magazine but have not got a reply as of yet.
The main reason I tried RL-15 was because I "heard" of blowups with IMR 3031 and IMR 4831. So far all the loads seem safe in my rifles but I do not want to risk damage when it can be avoided, especially as I shoot my doubles quite a bit.

Rusty, the only case I use any kind of filler in is the .510-.505 Gibbs. The next smaller case I shoot is .338-.378, and it does not need filler.

I have shot three powders in the .510-.505, WC 872, and IMR 5010, and WC852 (slow). I was being extremely prudent when I started, and I thought the WC 872 had made one or two primers that I thought were too flat, so I tried IMR 5010.

IMR 5010 is a large-grained extruded "Lincoln Log" powder. The pieces are actually so large that they will occasionally bridge in an RCBS powder funnel. Because the pieces are so large, the powder is fairly bulky, and 145 gr. filled up all of the space up to the bottom of the 700 gr. bullet and a little bit more (compressed load) and made only 2075 fps. The IMR 5010 had hangfired at least occasionally up to 135 gr. After getting such slow speeds and filling the case I knew I had misinterpreted the primers and I needed to switch to a faster powder. I think the 145 gr. load has some potential as a 100 yard target load. It certainly is a good introductory load owing to the feeble pop and moderate ballistics.

I had worried about high pressures with the hangfires and perhaps associated detonation, so when I switched to WC 852(slow) I used the polyolefin filler I mentioned above. There have been NO hangfires. Having previously read the caution in the A-Square Manual, we have been very careful and so far have only had normal or sluggish chronograph data (more powder not much faster), and no debris in the barrel or chamber. It seems that if the foam does not hang onto the case mouth, it is blown out.

It might be possible to discontinue the use of foam altogether shortly. I have used up most of the space under the bullet, though I think there might be room for 155-160 gr. of WC 852(slow) or so, which would be another 25 grains. As an aid in load development in large cases, I highly approve of its use. Hangfires of even .1-.2 sec are disconcerting, and we were worried that some relatively unreported and dangerous powder behavior might occur. The foam prevented the hangfires and kept us from worrying about bad consequences to us from pulling the trigger (other than recoil).

So far all I have needed is a bullet for load development. As long as it is accurate enough to make it through the chronograph, no other characteristic has mattered. A few years ago Widener's was selling 1000 collet pulled M2 ball bullets for seventeen cents each with free shipping. Well, shoot (of course!) that's as cheap as .308 HPBTs! I think I would have preferred the higher velocity of 600-grainers, but these do what I need them to do. They hold the powder in the case and weigh the same. Because of various deficiencies of the stock it has not been possible to fairly test for accuracy, but I suspect the reported-to-be inaccurate M2 ball might finish at just over 1MOA. We have tried once or twice to recover a bullet, but so far we have always failed to put enough of an obstacle in the way to retain the bullet, so they all go into the quarry wall, and we do not dig them out. Right now I am saving up 40 inches of newspaper. We would like some relatively pristine bullets with rifling marks.

I lost one case while I was necking them up. I had necked down .378 cases to get the .338-.378s, so this was the first time I had ever necked a large case up, which is a qualitatively different process than necking small cases up. I had read that the large cases are relatively fragile, owing to the disparity between the bore size and the neck wall thickness. I had no trouble after I started using graphite on the expander ball. The original attraction of the .505 Gibbs case was that it seemed likely that it would require very little modification to get to .510", but it turned out to be a little more work than I thought it would be.

I hope to try BP muzzleloader sabots with the JHP handgun bullets. I think this will be a real scream with speeds with IMR 5010 of around 3000 fps. If the bullets will hold together, the terminal ballistics should be good fun. I don't plan to chronograph them because without precautions, there is a chance the sabot will trash the system.

I have a few other hobbies that are time-consuming, chief among them bike riding (including tandems)and hiking. I go shooting once or twice a year in a normal year, sometimes not at all, perhaps more when I have something new to try. It seems like I always finish rifles to the 80% stage and never complete the job. Load development sometimes takes nearly ten years for any single rifle. I'd almost rather sit on a rifle range than shoot on a rifle range. For me it is supposed to be a relaxed-pace leisure activity. I have not been hunting in ten years. I might go somewhere in Texas next year. I will not get around to .510" hunting bullets before then.

RGB occasionally mentions that he built a .505 Gibbs Improved (!). I imagine he could report some adequate ballistics with hunting bullets.

There should absolutely NEVER be any airspace between any filler, wad or what ever and the bullet. IMO, this is where 90% of the problems come from, when useing any filler. The other is light loads of slow burning powder, WITHOUT any filler to take up the airspace.

The problem with loading the very large capacity of cartridges designed for Double rifles, that were designed for Black powder, or CORDITE, is they have too much capacity for modern smokeless powders, and must have that volume taken up by filler. The filler should be slightly compressed when the bullet is seated, with no open airspace! It is also my opinion, that the problem is not the filler matieral, but the loader that is most often the problem. The one exception is creme of wheat, the initial pressure spike cakes this cerial into a solid against the bullet, and if in a bottle neck it can really cause some very high pressure. This is the reason this medium is used to fire form brass WITHOUT A BULLET because it builds so much pressure without the bullet. Most barrel bursts in double rifles fail just ahead of the chamber. Ross Sefried says the use of IMR 4831 causes a higher pressure farther down tha barrels where they are thinner, I don't find that to be the case, however. I have been useing IMR4831 with Dacron fiberfill for years with absolutely no sign of a problem.

[ 12-27-2002, 01:09: Message edited by: MacD37 ]

Those of you who do not feel quite done with this may find clarifying remarks by JBelk, with picture, in the "Powder Residue on Case" topic, in Gunsmithing.

Once again SDS, the Article in question deals with only loading the 500 Express a black powder round. The other article delt with reloading the Nitro Express rounds. The only things common in each article was the use of Darcon polyester fill,and both articles delt with reloading for older double rifles.
He said do not use the foam plug for reloading a 500 express black powder round. Plain and simple.

Any other conclusions drawn from these articles are your problems.

Just the facts ma'am, just the facts.
-Joe Friday, Dragnet

Rusty
We band of brothers!

[ 12-28-2002, 19:05: Message edited by: Rusty ]

I think the main issue that needs to be looked at are combustion by products are they corrosive do they cause pressure spikes. do they cause sticky glue like residue around the chamber area? when I started smokeless loads for my 50 3 1/4" sharps there was a wealth of information not advailable in the late 1970s. I found a very good handy filler it is inert easy to find and works very well in straight walled cases. I use toilet paper infront of imr3031. I am saying to use what is of good known useful material. If you can afford to replace your guns play. If not you better use the expereince of men who could and did the work. P.S. if you want my recipe for whitetail deer and stray house cats email me and I will reply.