Dacron Filler

I am using dacron filler for the first time and need advise. I am loading 45-70 with 320 cast and A2400 [24gr] and a WLR primer. I already shot this load over a chrono and got some eratic results. So, I decided to use a dacron filler 1/2" thick cut approx. 5/8" square pushing it in the case with a pencil. The groups were more like a pattern at 100 yds. After I shot the initial bullets I had loaded I decided to up the charge 1 grain. What I noticed when I resized the cases was that the die met more resistance at the bottom 1/2" or so on the case. Leads me to believe the "powder detonation" with the filler occurred in the first 1/2" or so of the case. Maybe I am missing the obvious, did I do this wrong? Is the filler too much or packed to tight? Is this just normal occurrence with fillers? I sure would appreciate some advise.[smilie=b:

I've used Dacron in bottle necked stuff but never in straight walled ctgs , But the way I was instructed on its use was it pull it apart (fluff it up) and then insert on to the powder filling the remainer of the case ,if it's fluffed up it will easily do this . Don't just push it down in a semi solid wad on top of the powder and still have airspace .

Tim

My advice is to not use fillers. If you must use fillers, do it correctly, as RU pointed out. I would further advise to try H4895.

That is really good to know. I experienced those "erratic results" with 1680 in my 458 SOCOM w/starline brass-Wolf LRP and homemade 400g bullets. was planning on trying some filler. Thanks for the question and the answer.

There's a wealth of info on here about using fillers if you use the search function. I will tell you that you NEVER pack fillers in a case....NEVER. If you use a filler, you need to use a very small piece of it and "pluck" it to get that very small piece to take up as much room as possible simply by expanding it. It is supposed to only act to work as a barrier between the powder and the bullet. A very small piece of dacron can be lofted up from a small .5g piece to about ten times its original volume. What you're doing will end up ringing your chamber (if it already hasen't done that). I'd suspect your accuracy problem is much more bullet related that filler/powder related. I shoot a lot of 45-70 and use 2400 powder a lot. It's one of my most accurate loads. I have rarely, if ever, gotten my best accuracy with bullets lighter than 400g. I have gotten some "decent" accuracy with 350g, but not as accurate as the heavier bullets. The first thing you need to do is slug your barrel and find out what your diameter is and then get some bullets that are .001-.002" larger than the bore. Have you slugged your bore yet?

Larry Gibson did a good write up on it.

What I noticed when I resized the cases was that the die met more resistance at the bottom 1/2" or so on the case.

That is normal if the pressure is sufficient to obturate the case at that point. That area of the case is called the "web" and has thicker brass than the case fartherer out. It is also harder (not annealed) in that area. You might back the FL die out of the press so it sizes the cases only enough for reliable chambering. It will still be sized enough for good bullet tension. That will ease the harder sizing in the web area, work the brass less and give longer case life.

There is no "powder detonation", the powder ignites and burns. The 2400 powder is a relatively fast burning powder but may not be the best choice for 320 gr cast bullets in the 45-70, even with a Dacron filler. The problem could be as simple as the bullet mass is not enough for 2400 at 24 gr to burn efficiently for it to give good accuracy. I suggest working up to 27 gr, with and with out the Dacron filler. If that doesn't work you might switch to a powder such as Unique.....that's the powder I prefer for my 300 gr PB cast bullet loads in my 45-70s. TB may work better also.

When using Dacron as a filler make sure it is a filler. In post #2 I explain it; http://castboolits.gunloads.com/show...use-of-fillers. If you have read it and are using the Dacron filler correctly then it's the powder or charge of powder that is probably the problem.

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Originally Posted by Larry Gibson

What I noticed when I resized the cases was that the die met more resistance at the bottom 1/2" or so on the case.

That is normal if the pressure is sufficient to obturate the case at that point. That area of the case is called the "web" and has thicker brass than the case fartherer out. It is also harder (not annealed) in that area. You might back the FL die out of the press so it sizes the cases only enough for reliable chambering. It will still be sized enough for good bullet tension. That will ease the harder sizing in the web area, work the brass less and give longer case life.

There is no "powder detonation", the powder ignites and burns. The 2400 powder is a relatively fast burning powder but may not be the best choice for 320 gr cast bullets in the 45-70, even with a Dacron filler. The problem could be as simple as the bullet mass is not enough for 2400 at 24 gr to burn efficiently for it to give good accuracy. I suggest working up to 27 gr, with and with out the Dacron filler. If that doesn't work you might switch to a powder such as Unique.....that's the powder I prefer for my 300 gr PB cast bullet loads in my 45-70s. TB may work better also.

When using Dacron as a filler make sure it is a filler. In post #2 I explain it; http://castboolits.gunloads.com/show...use-of-fillers. If you have read it and are using the Dacron filler correctly then it's the powder or charge of powder that is probably the problem.

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I was just reading that post and I am using the filler incorrectly. I was using it more like a wad. I will try fluffing it up. I mainly wanted to know if I was doing something dangerous. I have shot over a chrono without filler [2400] and got erratic velocities, so I decided to try a filler. I have already loaded to 25 and 26 gr of 2400 with a "wad" filler and I gather it will be safe to shoot. If groups don't show signs of tightening up I will go with H4895 or IMR4198. Should I be using a large rifle primer with the 2400 loads?

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Originally Posted by dhom

I was just reading that post and I am using the filler incorrectly. I was using it more like a wad. I will try fluffing it up. I mainly wanted to know if I was doing something dangerous. I have shot over a chrono without filler [2400] and got erratic velocities, so I decided to try a filler. I have already loaded to 25 and 26 gr of 2400 with a "wad" filler and I gather it will be safe to shoot. If groups don't show signs of tightening up I will go with H4895 or IMR4198. Should I be using a large rifle primer with the 2400 loads?

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Your case takes a large rifle primer so you don't have any choice there. Do you mean "should I use a large rifle magnum primer"? The answer to that is probably a no, but you can try them. Sometimes you get better results. I load most of my 45-70 "hunting loads" with 2400 and don't use a magnum primer or a filler. I used fillers for a while and then compared loads with and without and didn't see any difference in my loads. This powder is just one of several really good powders for the 45-70 at mid-range velocities. I think you'll find 4198 to also be a good powder. If it were me, I'd be slugging my barrel to see what I have to work with. It's possible that your bullet doesn't match your bore.

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Originally Posted by NSB

Your case takes a large rifle primer so you don't have any choice there. Do you mean "should I use a large rifle magnum primer"? The answer to that is probably a no, but you can try them. Sometimes you get better results. I load most of my 45-70 "hunting loads" with 2400 and don't use a magnum primer or a filler. I used fillers for a while and then compared loads with and without and didn't see any difference in my loads. This powder is just one of several really good powders for the 45-70 at mid-range velocities. I think you'll find 4198 to also be a good powder. If it were me, I'd be slugging my barrel to see what I have to work with. It's possible that your bullet doesn't match your bore.

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Actually, I was thinking of a Wlp primer.

I use WLRs most often.

Not meaning to get off topic and, I will get to it. My first real experience with fillers was after reading Grahame Wright's book, "Shooting the British Double Rifle". His use of an open cell foam filler and the pressures Birmingham Proof House and Kynoch got when testing them with the old copper crusher method pretty much convinced me they were safe to shoot. Then Sherman Bell's series of articles on fillers fleshed out even more what I had experienced. After using open cell foam for close to, if not more than, 20 years I'm sold on them when called for. Chuck up a sharpened cartridge case of appropriate diameter in your battery drill and cut out a bunch in a hurry. Measure for length, cut them, put them in the case and nothing is moving. They also disintegrate on firing. I have yet to see a Unique, reduced load which numbers across the screens did not improve significantly with the addition of an open cell foam filler.

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Originally Posted by sharps4590

Not meaning to get off topic and, I will get to it. My first real experience with fillers was after reading Grahame Wright's book, "Shooting the British Double Rifle". His use of an open cell foam filler and the pressures Birmingham Proof House and Kynoch got when testing them with the old copper crusher method pretty much convinced me they were safe to shoot. Then Sherman Bell's series of articles on fillers fleshed out even more what I had experienced. After using open cell foam for close to, if not more than, 20 years I'm sold on them when called for. Chuck up a sharpened cartridge case of appropriate diameter in your battery drill and cut out a bunch in a hurry. Measure for length, cut them, put them in the case and nothing is moving. They also disintegrate on firing. I have yet to see a Unique, reduced load which numbers across the screens did not improve significantly with the addition of an open cell foam filler.

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I am not sure I have a handle on the method you mentioned. I think you are saying to use a cartridge case as a hole saw to cut filler?

I didn't explain that very well, did I. Yes sir, you're correct. As an example, I took a 40-70 SS case, cut off the head and sharpened the case mouth with an RCBS de-burring tool. Chuck that case in a battery drill and cut out the open cell foam cylinders. The foam I've always found has been about 1 1/2 inches thick and I have an old piece of industrial belting I lay the foam on. For me I've found that pressing the cut off case firmly into the foam, bottoming on the belting and a quick press of the drill trigger cuts out a perfect cylinder of foam. Cylinders cut using that case work very well in a large number of cases such as anything on the 8 X 57/30-06 case....or about anything close. For larger cases I cut off the head of a 45-90 case and sharpened the mouth of it.

In his tests Sherman Bell also tried closed cell foam and found it raised pressures too much so if you try it make certain you have the open cell foam. Once you know the difference they're easily recognizable. Closed cell is much more rigid than open cell. Open cell is pretty floppy....closed cell isn't. 'Course you probably knew that already. I think it is J.C. Munnel who uses Styrofoam packing peanuts with good results. I've not tried them but kept a bag full from somewhere if I ever want to.....as if I need more stuff laying around.

If I remember correctly the lowest pressures that Sherman Bell got when using fillers was with, of all things, cotton balls! As others have described, not packed in as with a wad but left fluffy.

Would floral foam (the stuff they stick fake flowers in ) be considered an open cell foam ?

If it's what I'm thinking of, no. Isn't that stuff more of a Styrofoam or rigid? Doggone it, I have a picture but haven't replaced photojunkit with a new host.

Are you familiar with those yellow, foam pads that are put under bed sheets? Those are open cell foam. I've used them but with all the....egg crate looking shape, they're a bit of a pain.