Dacron and COW filler

[caseyboy]

Hi All,

I copied this from the Cast Bullet Association website. The author is our own Molly.
For those who have tried loads as described below, how has the accuracy been? What velocities have you achieved with what calibers/bullets?

To use, assemble any sub-maximum load of your choice up to the point when you'd ordinarily be ready to seat the bullet. Insert a bit of light fluff such as dacron to fill the case to the neck. Fill the neck with COW. I don't weigh the COW any more, and still get good results. Then seat the bullet as usual.

Caveats and notes:

1. The usual warnings apply in spades. Drop your load by at least 10% from any handbook maximum. This WILL increase pressures a bit, and top loads need to be worked up with COW in the package from the start: It adds to the weight of the ejecta, and prevents the initial venting of 'young gas' that leaks by the bullet before it begins to move. If you have a round with a tiny neck, you might need to fill the shoulder with COW too.

2. The COW will form a hard cake behind the bullet from the pressure of the round, which will confine the gas behind the bullet. This is so effective at preventing etching and leading that one can use bullets as cast (if the neck dia permits), without sizing, gas check, lube, paper patching, etc. (They will often shoot BETTER without the lube.) Even loads that are maximum for jacketed bullets will leave the bore shiny and clean. Unfortunately, accuracy is seldom up to match quality, though the reports I have seen (and my own experience) indicate that 'reasonable' accuracy is easy to obtain. You shouldn't have much trouble hitting a wooden fence post at 100 yards or so, but don't expect any 'wallet groups' either.

HTH

Molly

Mike

[303Guy]

Now that's interesting! Thanks for posting.

(I still don't know exactly what COW is - I know it's cream of wheat but is it fine ground whole wheat or what?)

[leadman]

303guy, Cream of Wheat is a ground cereal that resembles brown sugar as far as size goes. The weight is much lighter of course. Probably just a little heavier than dry oat cereal.

[curator]

Cream of Wheat is finely ground Farina which is a very hard wheat. It does indeed clump up behind the bullet when used as a filler. It can cause pressures to sky-rocket if you don't work them up very carefully. Done correctly COW can allow you to shoot undersize boolits without leading and still give pretty good accuracy.

[dverna]

Caution for COW.

There was some testing done a few years ago by a guy who posts on SASS. I believe he was using either COW or "grits" loaded in a .45 LC.

It showed gradually increased pressures (eventually getting very high) as the stuff sat in loaded cases over a period of months. It was obvious it was a very bad idea to use the filler. The pressure started out OK and then went up - so pressure testing shortly after loading was not indicative of what the pressure would be 6-9 months later.

I will try to find the thread and post it here.

Don

[Larry Gibson]

I ran a test for the 45-70 guys here somewhile back using dacron and COW fillers. Under a 413 gr hard cast bullets (Meister);

25 gr 5744 gave 1166 fps with 18,400 psi(M43).

25 gr 5744 with a 3/4 gr dacron filler gave 1226 fps with 22,400 psi(M43).

25 gr 5744 with a 2.5 gr compressed dacron filler gave 1245 fps and 22,300 psi(M43).

25 gr 5744 with a COW filler gave 1294 fps with 33,000 psi(M43).

25 gr 5744 with a 3/4 gr dacron and a COW filler (Lee 108 dipper) gave 1288 fps and 27,100 psi(M43).

The best accuracy was with the 3/4 gr dacron filler.

I haven't used COW in bottled cartridges so won't comment there.

Larry Gibson

[Hang Fire]

LOL, thoughts of ground up dried cow pie came to mind.

[Larry Gibson]

I have been known to shoot lots of cow pies. 1st thing I learned, if shooting at close range, make sure they've dried up:redneck:

Larry Gibson

[crabo]

My testing with and without Dacron in the 45/70 guide gun. 40 grains of 3031, Starline Brass, WLR primer, CRed lube, and the 420460 group buy (plain based). WD WWs.

Velocity spread from high to low without Dacron 136 fps.
average 1440 fps
5 shot group at 75 yards, 1 5/16ths"

Velocity spread from high to low with Dacron 85 fps.
average 1475 fps
5 shot group at 75 yards, 7/8"

Now, when I switched to air cooled 50/50 pure lead and WWs, my groups shrunk a 1/4 of an inch. I have not chrongraphed the 50/50 loads yet.

I don't feel like my gun is really broken in yet, but it shoots better all the time with no leading after about 100 rounds with no cleaning.

[caseyboy]

First of all, I cannot see the COW of packing up in the cartridge because the only pressure the COW feels, before ignition of course, is the pressure of the dacron pushing back. A neck full of COW in a 7MM-08 cartridge is about 2.5 grains. This weight must be added to the weight of the bullet.

Tried out 50 rounds today in the 7mm-08. Starting with 14.0 gr of 2400, 1.0 grains of dacron and a neck full of COW. The bullet is WDWW and the lube is thinned LLA applied as a very thin layer. The 14.0gr group of five shots was about 5" at 100yds. Not real encouraging.

Next is the same as above with 14.5gr 2400. This group measured about 3". Not great but encouraging.

15.0 grains of 2400 gave me a nice round group of 1 3/4".

15.5 gr back to about 3" and finally 16.0 grain looked like buckshot.

Primers looked normal with rounded edges and extraction was easy at all charge weights.

This is not conclusive by any stretch, but looks like this idea has merit and I will be trying different loads to see how tight I can get the groups. Next I will try some IMR4227, a bit slower powder.

As I have no chronograph or pressure reading equipment, I cannot guarantee that this is safe, however, I did not observe anything to give me concern. Please do this at your own risk if you wish to try this.

Mike

[williamwaco]

I ran a test for the 45-70 guys here somewhile back using dacron and COW fillers. Under a 413 gr hard cast bullets (Meister);

25 gr 5744 gave 1166 fps with 18,400 psi(M43).

25 gr 5744 with a 3/4 gr dacron filler gave 1226 fps with 22,400 psi(M43).

25 gr 5744 with a 2.5 gr compressed dacron filler gave 1245 fps and 22,300 psi(M43).

25 gr 5744 with a COW filler gave 1294 fps with 33,000 psi(M43).

25 gr 5744 with a 3/4 gr dacron and a COW filler (Lee 108 dipper) gave 1288 fps and 27,100 psi(M43).

The best accuracy was with the 3/4 gr dacron filler.

I haven't used COW in bottled cartridges so won't comment there.

Larry Gibson


Very interesting.
In my testing with the .38-55 I settled on .7 grains dacron.
However I did not find any improvement in accuracy over no filler at all.
I was using Unique.

[Larry Gibson]

williamwaco

Found no improvement of accuracy with Unique to be common. If I use a filler with Unique it is just to prevent powder position sensitivity and resultant wide velocity spreads from that.

Larry Gibson

[geargnasher]

That's one of the unique things about Unique :groner:

..and one of the advantages of that powder.

Sometimes a small tuft of Dacron can make a huge improvement, sometimes none at all. It depends a lot on the case and powder being used. One brief example, I tried Longshot for 1500 fps, plain-based .30-30 loads to get the pressure curve I wanted with the velocity I was after. The load grouped erratically until I added about a grain of Dacron to hold the small charge of powder against the primer. Very low-density charge of slow-burning pistol powder.

Gear

[swheeler]

That's one of the unique things about Unique :groner:

..and one of the advantages of that powder.

Sometimes a small tuft of Dacron can make a huge improvement, sometimes none at all. It depends a lot on the case and powder being used. One brief example, I tried Longshot for 1500 fps, plain-based .30-30 loads to get the pressure curve I wanted with the velocity I was after. The load grouped erratically until I added about a grain of Dacron to hold the small charge of powder against the primer. Very low-density charge of slow-burning pistol powder.

Gear

No kidding! Wow you're catching on.:kidding:

[MikeS]

Does the comments on COW also pertain to shotgun buffers like PSB? I have some PSB, and loaded some 45LC rounds using 1cc of PSB on top of 4.2gr of TrailBoss. Is there any problem shooting a load with PSB or COW out of a revolver?

For those that don't know, PSB is Precision Reloadings Spherical Buffer it's made out of some kind of plastic, and is supposedly perfectly round which I guess aids when used as a shotgun buffer as it was designed to be. There were some articles about using it with cast boolits, but I don't recall what website they were on.

[303Guy]

Something I discovered with shotgun powder and wheat bran filler is that even though pressure seemed low, the case neck would expand into a few rust patches and lock up the case. Much heavier loads of slow powder don't do that with this rifle. Chamber ringing knocking on the door? There seems to be a pressure spike in the neck region. The same thing happened with a light tuft of cotton wool filler (one that filled the case). More to do with the way pressure builds up and sets up shock waves than the filler itself but the filler could act as a 'ram' perhaps?

[Char-Gar]

Let me take a run at this....

1. I stay away from COW or any natural vegetable filler. While it does have some advantages as per Molly's post. They have the potential to absorb moisture from the air and expand and/ harden in tough cake. This can cause an increase in pressure as already mentioned. If in a bottle neck case, the pressure increase could be enough to be a safety concern.

2. Lots of folks use Dacron tufts and all report good results. There have been concerns about ringed barrels with this stuff and that has been debated back and forth for years with no resolution or consensus.

3. My first preference is to use powders that do not require the use of fillers or tufts. I can get all the accuracy I want or can use from powders like 2400, 4759 and 4227 and they do fine without any extra stuff on top of them.

4. The only filler I will use is PSB. I use it to top off loads of very slow ball machine gun powder to give compression for a good burn and accuracy. I would not use it on top of any powder charge that does not fill at least 70% of the case capacity. I would also not use it with stick powder which might allow it to mix with the powder.

5. Any filler adds to the weight of the ejecta and loads should be worked up with it in place and do not just add filler to an existing load.

6. I have have not used PSB under sixgun loads, but others report that doing so gives good results. That stuff is reported to act like a gas check to protect the base and sides of plain base bullets. I see no reason why that should not be correct, but I have not tried it.

caseyboy...try 16/2400 with none of the other stuff. Do that and report back your experience.

[felix]

More to do with the way pressure builds up and sets up shock waves than the filler itself but the filler could act as a 'ram' perhaps? ... 303GUY

Exactly. ... felix

[1Shirt]

Have used COW with straight or near straight cases, 45-70,444 with sucess, but it is a lot more of a problem mess wise than Dac fill, which is what I prefer.
1Shirt!:coffeecom

[Tatume]

Hello Folks,

After having poor results with Dacron, I decided to try Cream of Wheat as a filler. My load was one that produces 1400 fps with a 400 gr bullet in the 45-70, with moderate accuracy.

Cases filled to the top with COW would not retain the bullet long enough to change dies and crimp; the bullets pushed back out too far for the rounds to be chambered. Also, wheelweight bullets were deformed in the process of seating. Completely filled cases were unusable.

Using a 1.3 cc Lee powder scoop to dispense COW left 1/4" of space at the top of the case. This gave a satisfactory degree of compression. Bullets were not deformed, and did not rise out of the case. Only a moderate amount of crimp was used, mainly to iron out the bell so cartridges would chamber. Otherwise, the Winchester High Wall requires no crimp.

Accuracy with the RCBS 45-405-FN and Lee 457-405-F (my only plain based mold) was very good. At 100 yards using iron sights, 20-shot groups measured four inches. The LBT 460-400-LFNGC seemed even better, but I only had six shots to shoot for group. Although they went into less than two inches, I don't consider the sample size great enough to have meaning.

Average muzzle velocity was highest with the LBT bullet, at 1724 fps. The RCBS bullet ran 1644 fps, and the Lee made 1690 fps. This is a substantial increase over the same load without filler. The load without filler is a Trapdoor load, and the gun is a strong action capable of much more.

All in all, I'm very pleased with my experience with COW filler. I'm looking forward to another day of shooting the High Wall with this ammo.

Take care, Tom

[Tatume]

Hello Folks,

Today I shot this load again using the LBT bullet. This time I shot a number of five-shot groups at 100 yards, again using iron sights on a Winchester High Wall. Groups were uniformly two inches, fired hand-held with elbows on a shooting bench. I'm very pleased with the load.

With straight-walled rifle cases I find that resizing effort gives some indication of pressure. I've fired 45-70 and 458 Win Mag loads that required I hang my 200+ pounds on the press arm and wait while the case slowly enters the die. It is very exhausting. On the other hand, low pressure loads require very little effort to resize the cases. These are low pressure. The effort is very slight.

At more than 1700 fps with a very blunt 400 gr bullet and with excellent accuracy, I'm very pleased with the load. This is a top Trapdoor load of IMR-4198 before the filler is added, but with 1.3 cc of COW I couldn't recommend it for a Trapdoor Springfield. However, it's a perfectly delightful loading in the Winchester High Wall.

Take care, Tom