I have recently started loading some 45-70 and 50-70 and many loads call for the use a small charge of a relativly fast burning powder and a cotton or dacron filler to keep the powder positioned against the primer. I just had someone tell me this could cause damage to your gun (ring the barrel). what concerns do you have with this practice. I am currently loading a 50-70 with 450grn bullet 26grns of IMR 4198 and about a 1 inch square of cotton batting, it chronagraphs at 1170 and is very consistant. Should I use the synthetic batting rather than cotton? this was suggested in another thread.

I have used the cotton with out any problems in the 45/70 using unique and 405gr. lead bullets. Works good for light plinking loads
I was told that a air gap could ring the barrel , so Ihave put in enough cotton to take up the gap between powder and bullet.
The only thing then to remember is that when the cotton comes through, it could start a grass fire.
Have fun

Straight walled cases respond to fillers quite well, Bob - its the bottleneck cases you have to be careful of ringing the barrel just ahead of the chamber.

Using either cotton, kapok or dacron - pinch it off, fluff it out and insert into the case. A small amount is all you need. If you make a tight "pill" out of it, could get a pressure buildup. All you want is enough to hold the powder column against the primer and not be rattling around loose.

The August issue of Handloader magazine has an article on reduced loads for cast bullets and demonstrates the pinch of batting for filler.

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For a time, that "somebody" that advised against fillers was the NRA...they may still for all i know, I've not checked. I don't use them if I can get the perfomance I desire without them...not so "wedded" to a given powder that I'll use a filler to get it to work right, will try other powders until I find one that performs to my sadisfaction without a filler.

There have been instances of straight walled cases ringing a barrel without fillers...and have been cases of them ringing a barrel with fillers. Filler does make consistant accuracy (less position sensitivity) more easy to find, but I do not believe it gives immunity from chamber rining. If it woeks for you, then keep on using it.

Am also a 50/70 fan, but do not load many smokeless forunds for the old rifle. When I do, usually use 4759 (22.5gr. under a 450gr. Lee bullet earns 1150fps from a 36" barrel). 24gr. of 5744 will about equal that, but oddly the same charge will get 25 fps MORE velocity with a 515gr. bullet (another Lee).

Bobinil,
I have been using Dacron in my 45/70 reloads for many years with no hint of any problem.
Some say that,because it is a synthetic material,Dacron is dangerous,and cotton,being natural material is better.
On the other hand,cotton is denser/heavier then Dacron,and forms a wad inside the case. If you tamp the Dacron down onto the Powder surface,you can't form as much of a wad.
That is my reason for not using ccotton.
Frank

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I am using some 100% cotton batting I bought at a fabric store that is about 1/8 of an inch thick, I cut it into about 3/4" squares .5 grains in weight and then lay the sheet of batting over the case mouth and poke it in the case from the center so all side fold in to the center the bullet is seated on top but not compressed at all. I can still hear a very slight sound of powder rattle when I shake the finished case so I know it isn't compressed. I shot a couple of these through my chrony last night and was getting very consistant velocities. less than an 8 fps deviation. I am still getting some unburnt powder with the 5744 but if this load gives the accuracy I want I can live with a few unburnt powder ganules. Overall the load is as follows 50-70 bertram brass, WW large rifle magnum primer, 26 grns of 5744 .5 grn cotton buffer and a 450 grn bullet MV of 1230 fps. I measured the case head just above the rim after fireing and it was exactly the same diameter as a newly resized piece of brass, no expansion. I may still back off a grain to be safe.

This is interesting to me.
Could someone please explain this problem of ringing the barrel in more detail for me?
I have never heard of this before.
What exactly happens in the barrel to cause this? Thanks...flinch

Dacron is a synthetic material and when it burns it leaves behind a platic type residue so to speak...cotton will just burn and turn into dust pretty much...so i can see where you MIGHT have a problem with dacron, but ive never heard of problems with either. IVe used real cotton for years now and havent had a single problem with it...a bag of cotton balls at wally world is dirt cheap and will last ALONG time.

AA 5744 powder is the dickens to get to burn right. Been using some in my .45LC to use it up and have the same problem with unburned granules - even went to a mag primer and cotton fluff filler. A friend that tried using it in his replica Sharps 45-70 had the same result.

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I just tested it for accuracy and am quite pleased. I printed a 3" group at 100yds and just under 6" at 200yds. Not bad for a 135 year old gun with crappy sights. I can live with a few unburnt ganules at this rate.

In the five or six articles I've read on this over the years, no one else is 100% sure what's happeing either. IF a chamber is going to get "rung" ( a raidal expansion or buldge that looks like a dark ring) it will usually be located at where the base of the bullet seates in the cartridge. Have been reports of cahmbers run when using less than case filling powders without fillers and also with fiber fillers. Haven't read of any ringing problems with compressed granular fillers or with powder charges that take up most of the case volume.

The obvious answer to "why" is that pressure rose rapidly and that pressure wave saw the bullet base as an obstructioon. Obvious, but it doesn't really explain the "how come" of it. They don't seem to be in agreement on how it happens...some have written that the fast powders that such low volume loads rely on can burn fast enough that pressure builds faster than the bullet's ability to move.

Others have argued that the filler actis as a light weight.vast moving projectile that slams into the base of the bullet. Even case filliung "fluffy" wads of fiber son't move all at once...the fiber near the powder moves forward at the same rate as the powder gas, kind of an "accordian" effect that eventually stops when bullet base is met.

Darned if I know...but each side put up a good argument and sited examples of ruined guns.

Many years ago I managed to "ring" the barrel of a Sako Forester, .243 Win. Was using H380 powder and read that the case should be full to the base of the bullet for best accuracy. Poured in some recommended corn meal as a filler to the bullet base. First shot resulted in a greater than normal barrel jump and a sticky bolt lift. Primer was flattened, blackened and the case had a big bulge at the web. Swabbed the barrel and looked down - sure enough, there was the dreaded dark "ring" just ahead of the chamber.

My thinking is as RS has stated - the cornmeal bridged off in the shoulder of the case and when firing acted like a plug, allowing greater pressure to build. The bullet may have started downbore movement, hung momentairily and then got booted by the plug of cornmeal.

Never ever used anything else except kapok, dacron or cotton for fluffy fillers after that! Haven't repeated the event and have had better consistency with velocities, spreads and accuracy.

The thought of filling the case as full as possible with slower burning powders that can be used is the ideal way to go, avoiding having to use fillers. The problem is, some firearms just don't respond accuracy wise with these powders for the chosen bullet and weight. You have to experiment with what your particular firearm shoots best, then go with it. If at all possible, I'll go with the case full of slower powder in lieu of the fillers.

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Kdub,
Your post is an 'eye opener'.I have been following reports of chamber ringing closely for the past year,and you mention the only case involving granular filler. Is it possible that you compressed the filler.That will cause it to form a solid mass,and then cause trouble.
If you want to check,load some up,and let them set for awhile.Then pull the bullet,and see if you need to pry the filler out.
I have done that.Even Puff-lon,a fine powder expressly made for use as filler will do it.
Frank

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The discussion on fillers is one I always follow because I use kapok fillers and I have read enough to always have a bit of doubt. the confusing thing to me is that whenever I read of a barrel that has grown a ring it is a few inches down the tube at a point where filler and powder and bullet have all collided well before. My thinking is is that the powder and filler will move on the power of the primer alone. Buy the time the powder is in full ignition and enough pressure has been built up to overcome the inertia of the mass of the bullet the filler is packed tightly against the base of the bullet. I have been advised to use a coffee can lid plastic wad to protect the base of my bullet in my 45/70 from being etched with powder grains which are pounded into the base at ignition. If that is the case then my little tuft of kapok is probably a thin waffer by the time the bullet starts it movement. On another forum we were debating barrel vibration and one engineer stated that other engineers in the gun world told him that all barrels exhibit a tiny running bulge as a bullet passes down the bore. I guess ringing occues just from pressure. A point where the running bulge does not bounce back and leaves a ring. A few inches down the bore is where I have always been told max pressure is achieved. As you can tell this topic interests me. JB

The point of max. pressure is probably not the point of max. stress to the projectile. Would guess that the travel distance BEFORE max. pressure is more stressful to the bullet, with a big bit coming in the first movement to overcome inertia/force of engravment.

Yeah, Frank - I'm sure the .243 load had a bit of compression on the cornmeal.

My line of thought though, is that granular fillers, compressed or not, have a tough time negotiating the reduced body of a bottlenecked case and will "bridge" momentarily at that point before releasing down the neck and into the bore. A straight walled case doesn't have these complications.

I'm further convinced the bullet and mass in the case (powder and filler) DO start forward movement prior to the full powder ignition. If the filler bridges there will be a momentary pause of the bullet until the pressure builds to the point of blowing the filler on out the case neck and then the filler and pressure come up against a stalled bullet, which takes a bit to develop further momentum. That, I believe is where the ringing (swelling) occurrs.

Been thinking of writing a short piece for Marshall here on the board on fillers to be included in the Tech Notes section. Have done a bit of background research only to find there is surprisingly little written previously on the subject. Evidently, everything heretofore has been word of mouth or tiny blurps buried in some other topic. There is a pretty good article on Puff-Lon filler in the August issue of Handloader magazine. That's the most complete article I've found so far.

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KDub,
Yes,there is a lot of 'talk' about fillers on the Web,but very little actual presentation of facts.
I've pounced on every discussion of fillers that I discovered on any website and haven't learned a lot. the best discussion was on the 'Cast Boolets" Site, a few months back.
I saw that Puff lon article in 'Handloader'. I'm the only person that I know,who uses it.
If you are interested,I'll be glad to share the little data on fillers that Iv'e gleaned this past year.
To get back on track here. I always thought that granular fillers would be less likely to cause a chamber ring because,even if it is compacted into a wad,the wadsits at the base of the bullet itself. It can't 'ram' the bullet,if it rests against it.
Obviously,I was wrong.
Frank

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Would appreciate any and all info you have gleaned on fillers, Frank - Will add it to my meager pile and see what I can do for a writeup.

All I know is I've never used a granular filler since ringing the Sako. Have used pinches of dacron and a little hoard of kapok that's long since gone. Never had any problems with either of these. The Puff-Lon may be something to consider, although I'm not wild about the moly it contains.

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A little distant here from the original topic , but when I was fireforming cases for my 240 Gibbs I ended up with one case that had a solid chunk of instant wheat left in it after firing. The case formed fine but had to break up the chunk to clear the case. That was one out of about 80. Not really sure if it was just a fluke or if a different filler is being called for, but just the same it went solid.

Cast Bullets by Col. E.H. Harrison USA (ret) is a NRA publication; First printing 1979, Second printing 1980, and Third printing 1982 have articles about cartridge space fillers that were in "The Rifleman".

If you can find a copy, its a good reference for the bullet caster of today. I've used dacron over SR4759 in 30-06 cases for years with no ill effects.

Keeping my fingers crossed..............

Hoopie,

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