Case filler with cast bullets on reduced charges

[Turkeyfeather]

The question I have is on the use of case fillers. I have been, what I believe, successfully using Dacron fiberfill to offset the empty space in the case when loading reduced loads and cast bullets. This has enabled me to get complete ignition and good accuracy, respectable velocities, as well as reducing the concern for barrel leading at the resulting speeds.

I have used this philosophy on the 8mm Mauser, 303 Brit, 35 Whelen, and 45-70 cases with no clear indication of excessive pressures or concern. Perhaps I was lucky or perhaps there is some science to the percentage of load used and the use of the filler material.

In the paper written by Mr. C.E. Harris, on "Cast Bullet Basics for Military Surplus Rifles", he considers it strictly forbidden and briefly states it raises chamber pressure and contributes to chamber ringing.

I have been casting and handloading cast rifle bullets for over twenty years and many of the earlier writings I have used as technical knowledge had routinely used kapok, and other inert material to top off the powder charge to ensure proper ignition and uniform performance. While technology does advance and new information does condemn some of the old practices, I am a concerned about this report.

For example, in my 35 Whelen I have changed a very poor performer into a successful hunting load. I had experimented with using a Lyman 358315 w/w bullet, 204 gr., charged with 38.2 grains of IMR 4895. It gave me a calculated velocity of approximately 1,900 fps. The challenge was that the performance was very sketchy and inconsistent. After inspection and evaluation I noticed unburned lead particles left in the brass case. I quickly went to the rules of the past and took up that notable free space in the case with a case filler material. I noticed no indication of pressure change on the case or primer and from the human side, the charge felt no different on the shoulder. The performance outcome was just great and the load is now one of my main selections for that rifle. I get almost no barrel leading and I can punch consistent 100 yd holes.

While my success maybe a result of good fortune or perhaps a note to soften the condemnation of the use of filler materials. Considering Mr. Harris a well informed technical writer and validity of his statement, I would like to get comments and perhaps other technical reports on this topic. Let me know your views and experiences with this.

[StarMetal]

In the paper written by Mr. C.E. Harris, on "Cast Bullet Basics for Military Surplus Rifles", he considers it strictly forbidden and briefly states it raises chamber pressure and contributes to chamber ringing.

But Mr Harris wasn't always that way about filler. Just read the NRA Cast Bullet book. He highly recommended it there. I just wonder if his change of heart came from legal issues.

Joe

[Buckshot]

.................I have used it since almost day one of my cast boolit casting career, where ever I felt it was called for. I have NEVER to date had any issues or problems of any kind. That includes high pressure excursions, or melted dacron barrel fouling.

I have read of the SEE phenomenom, and of simple high pressure excursions, and ringed chambers or barrels because of it. I would imagine if it hair lipped the Pope, I'd still use it. I've used it consistantly in every rifle cartridge I have, from the 6.5 Carcano to the 577-450 M-E.

If, at some time something untoward happens that I can pin on the use of the filler, I'll take a second look. Until then, I'll continue to use it and enjoy it's positive rewards. I do NOT use it with powders faster then Unique, nor do I use it in pistol cartridges.

.................Buckshot

[Roudy]

After inspection and evaluation I noticed unburned lead particles left in the brass case.

Your comment about lead particles in the brass case intrigues me. Recently I was working up a load for a 45-70 405 grain plain based boolit and had serious leading. Using FFg or IMR3031 left lots of lead in the bore. I started using a card wad (with dacron filler for the IMR3031) and found virtually no leading for either powder...accuracy improved as well.

My thought was that the heat of the burning powder actuall melted a bit of the lead on the base of the boolit. Someone told me that this wasn't possible, but after reading your comment I'm beginning to beleive it may be so.

I also use dacron filler and have experienced no problems, but I haven't any scientific data to support the use or non-use.