How much Dacron?

[4296]

While I am concerned and apprehensive about using any type of filler in cases, I have seen the benefits with a chronogragh and through group size. I do weigh my tufts but am unsure as to the density I should be trying to obtain. Two examples: in the 375 H&H with the Lyman 264g. FN GC and 33g. H4198, and the 45-70 with the Lyman 385 RN and 33g. H4198, a 1.5g. tuft of dacron will occupy completely the empty airspace with a fairly dense mass that can still be compressed. The 375 load is accurate and gives consistent velocities. I will try the 45-70 loads in a few days. My concern is that i my be using too much fiber as the amount seems to be too dense. Should dacron be used minimally and should it take up the complete empty space or just a portion? Thanks!

[swheeler]

It should take up the complete space, dacron should rest on top of the powder and be slightly compressed by the bullet base. As far as weighing the dacron, I don't, but instead cut into pieces that are large enough to occupy the air space left in a charged case.

[Larry Gibson]

It should take up the complete space, dacron should rest on top of the powder and be slightly compressed by the bullet base. As far as weighing the dacron, I don't, but instead cut into pieces that are large enough to occupy the air space left in a charged case.

I use an aweful lot of dacron as a filler and concur with swheeler.

I have measured the psi in both the 375 H&H and the 45-70 and numerous other cartridges also. I have found that weighing the dacron is wasted effort. I have weighted pieces of various weights for reference and just eyebal it when cutting the chunk to the desired size. The more important aspect is making sure it fills the sapce. A slight compression with the bullet base is what I use also.

Larry Gibson

[onondaga]

I have used a variety of fillers in .458 Win Mag, .500 S&W Mag. (rifle) and .308 Win. and .223 Rem. Dacron is the lightest and that is important but after considering other factors I gave up on Dacron for a couple of reasons:

1, Dacron and other cloth or fiber batting materials have to be cut by hand and individually fit into the cartridge case.
2, The powder burn is capable of burning around the Dacron and leaving it in the cartridge or bore causing an unsafe condition.

I have used Dacron, cotton fiber, bulgar wheat, Farina cerial, cracked corn, grits, Dietary cellulose fiber, and 2 commercial inert buckshot buffers as ballistic fillers in the calibers above with powder charges less than 80% of case capacity.

The scary thing that causes pause for tinkerers is pressure. The weight of any filler must be added to the weight of the bullet for a total projectile weight as the filler is fired from the rifle along with the bullet. So load calculations need to consider total projectile weight when checking for pressure safety and charge weight.

I have had the best results with BPI Original Filler. It is a flake or granular high heat plastic used with buckshot. It meters well with my Lyman#55, Lee Perfect measures and also measures well with Lee scoops. To figure filler volume I calculate case volume with bullet seated in cc then subtract powder volume in cc for volume of filler needed and add 5% of the total volume more filler for a 105% compressed load. An easy to understand example is if the total volume with bullet seated is 105 cc, and powder volume is 50 cc then filler volume is 55 cc for a 105% compressed load. Important in the example is to measure the weight of that volume of filler and add it to the bullet weight for your load calculations.

I have also used Precision Reloaders Spherical buffer (PRPSB) it is tiny inert plastic balls. Unfortunately it is twice the weight per volume of the BPI and has no gas checking effect like the BPI has on plain base lead bullets. They both scrub the bore to a small degree and harmlessly clean bores.

The compressed loads give great ignition with some unlikely powders. My best example is with H4895 in my .458 with reduced loads. There is lots of unburned powder down the bore if I don't use filler for a 105% load. Rel #7 reduced loads without filler produced squib loads, misfires and detonations with fiery muzzle blasts from my .458. Filler completely cured the problems.

BPI source:
http://www.midwayusa.com/viewProduct...tNumber=695248

gary

[chasw]

I've been using Dacron in my cast boolit loads for a while now. It definitely fixes the inconsistent burning you get from small charges in large cases. For example, I load a 300 grain boolit over 36 grains of RL7 or IMR4198 in a .375 mag case for about 1950 fps.

The Dacron does its job well, consistent velocities and no fouling in the bore. You can see the little fibers floating to the ground in front of the bench after each shot. The only downside is the time it takes to measure out a suitably sized tuft of dac and stuff it into the case, down against the powder.

I have a bottle of Grex, a shotgun buffer material consisting little lightweight plastic beads. Based on 4296's observations, I think I'll give it a try using my Lee powder scoops for measuring. Should be a lot faster to load. - CW

[zomby woof]

I recently bought more Poly filling. I bought 8oz and 10 oz "Batt". It is a flat fiber of different thickness. The easiest way I've found to get my filler is to cut squares of the filler to add to different cartridges. I need about .4-.5 grains in my 30.06 41.5 4831 load. A small square (about 3/8 X 3/8) of 8 oz batt fits perfect and I can make many in a small amount of time. For my 6.5X55 load of 16 grains 4198, a small square of 10 oz batt works just perfect, about .5-.6 grains. I've found this to be the easiest for me. I insert them with a straight pair of tweezers and fluff it as I place it in the cartridge. Works great.

[Papa Jack]

Be real careful if using those batting type filler materials in cases with shoulders such as the ones in the photo. While the material may be a good filler, I suggest that you pull the fibers apart and "fluff" it up and use a loose fill inside bottle neck cases.
The reason is as you poke the filler in the case with a pencil or dowel , when the case is fired that big wad is forced against the small neck in the bottle neck and must be forced out of the case,kinda like a "plug" this raises pressure big time. So check your cases for pressure signs.
I had a few problems using cotton ball fillers in some 30-30 cases.....
Just be caefull, I hate to see anyone ruin their day of shooting....... "PJ"

[onondaga]

No fluffing is required with BPI Original Ballistic Filler. It can be measured with scoops or a powder measure and poured directly into cases with a scoop or dumped right in with a powder measure. It also works fine in bottleneck cases as is. If you have to have the best predictable filler, resistance is futile.

[Larry Gibson]

No "fluffing required with dacron (polyester) "batting". I've been using it, chronographing it and pressure testing it for years in bottle necked cases from .22 to .375 cal and have never had any indication of pressure spiking from it "plugging" in the neck. I had nothing but petter ignition and better accuracy when used with the appropriate powders.

I've posted thia numerous times, perhaps it will help here;

I don't use cotton for several reasons. I have for many, many years found dacron (polyester fill) to be the best "filler".

I don't use the dacron filler or a wad either with the fast to medium burning "fast" pistol /shotgun type powders. I find a fast burning powder that is fast enough to ignite and burn efficiently at the velocity I want.

For use in rifle cases with slow “fast” burning powders (4227, 4759, 5744, 4198, etc.) up through the slow burning powders that give around 80% or less loading density I use a dacron filler between the powder and base of the bullet. The “dacron” is polyester fill as commonly found in pillows and toys. It also comes in sheets called “batting”. It can be obtained very reasonably at most any fabric store.

The dacron batting comes in various thicknesses. I prefer that which is about 5/8" thick. My wife recently bought me 10 yards which will give many, many thousands of cast bullet loads. With this current batch of batting I cut it initially across the width into strips about 3/4" wide. I then "eyeball" cut 1/2" wide chunks which is close to 3/4 gr.

A smaller chunk is cut for 1/2 gr and larger for a larger amount. I've cut some chunks that weight 1/2, 3/4, 1, 1 1/4 and 1 1/2 grs and have them in a "snack" baggie stuck on a poster board above my loading bench for quick reference when I need to cut new chunks. The batting will run thin and thick throughout the sheet so I again just "eyeball it" based on the thickness of the batting when cutting the chunks.

Pretty extensive tests have demonstrated that the weight of the filler does not have to be exact, only close. What is important is that there is enough so that it “fills" the space between powder and bullet. A little too much hurts nothing but too little poses problems. That's why I have the different size "chunks" so I can use the right size for the case capacity I am filling. For example; with most medium burning powders (3031, 4895, 4064) in and '06 to function an M1 a 3/4 gr dacron filler is about right. With slower powders that give a higher loading density like 4831 a 1/2 gr filler is about right.

I use a section of .22 cal cleaning rod in cartridges of .30 - .375 cal to push the Dacron chunk inside the case just so it is all in. The 6 to 10" section gives plenty to hold onto and sufficient "feel". Merely hold the chunk of dacron over the case mouth and shove it in with the rod. Sometimes it takes a couple three pokes to ensure all is inside the case mouth. I poke the chunks in until the are at the botom of the neck or at least all in the case. It doesn’t matter. What you want is to let the base of the bullet finish pushing it down and adding any compression. Thus I do not push it down on the powder but let the bullet do that when the bullet is seated. Using the right size chunk of dacron this method then provides a "filler" in the air space between the powder and base of the bullet.

A small length of coat hanger works for the .22-7mm cartridges and an unsharpened pencil works well for .45 cals. Larry Gibson

[Shooter6br]

I use drier lint. A small puff 1/2 grain. Wife likes it since she doesnt have to clean the lint trap A win ,win situation ( wink , wink)