filler usage for reduced loads 450/400ne

[209jones]

I have been looking for info on fillers and how to decide how much filler to use in a reduced or lower volume load. I have a 450/400 3" NE in a #1. I'd like to work up some loads for that will likely be best used with a filler.
The material to use appears to be Dacron, the procedure to install it is straightforward, but, I haven't spotted the process for determining how much to use being discussed at length. A few mentions of weighing it, one mention of adding the weight of the filler to the bullet weight to calculate the load.
Haven't seen anything usable about how to determine what is enough filler or what constitutes too much in a load, other than compressing some materials is not a good idea.
I could use some info on a procedure to use on this subject.

[onondaga]

I have posted a number of times regarding adding the weight of filler to the bullet weight for a total projectile weight to be used in calculating load safety. That is related to the use of particulate fillers like BPI original, and Precision Reloader's spherical buffer. Those buffers are generally used as a Buchshot buffer but are also suitable as a ballistic buffer when the precautionary math is calculated. These buffers typically weigh 12 grains and up in my reduced .458 Win Mag loads.

Dacron is much different and very much lighter in weight to fill a volume. One grain or a bit more of Dacron filler is a lot of volume and as such, weight calculations are not needed for Dacron. Dacron certainly can be overstuffed into a case and has the potential to cause problems, But if you fluff it up good and only use enough to fill the air space and keep the powder from moving, you have conquered the Dacron method.

My choice to prefer the BPI is solely based on how my Lyman #55 powder measure consistently measures and dumps BPI so easily and the loads I use are really equal to medium 45/70 loads in my .458 WM so pressures are never a problem with the added weight of the BPI in my loads.

Gary

[Von Gruff]

Pity you guys are handicapped by living in the US, Canada and parts other than NZ:kidding:

Here in NZ we can and do use a wool wad as sold by JefinNZ and as these are bagged and the perfect size they take the filler process to an easy level. I have used them in my 404 Jeffery and 7x57 with complete sucess. When I was using dacron I got it in sort of sheet about a 1/2 in thich and I would cut 1/2 in strips then cut 1/2 pieces of the strip. That was enough to hold the powder back in the 404. Slithtly smaller pieces in the smaller case.
As Gary says though I made no allowance for any weight variation.


Von Gruff.

[209jones]

That helps define what I thought I was reading on it. There are a lot of posts on fillers, a lot of opinions and products expressed, but, the dacron made the most sense to me. I won't use it unless things push me that way, but it is an option I'd like to have available, if I feel it is a practical solution down the road. At his point I will start with lighter bullets and full power charges, see how those work. If the bullets can't handle that, then I will try Trailboss next. never bothered with fillers before, but, this cartridge may just take me there yet, we will see. This cartridge has some interesting possibilities.

[Cap'n Morgan]

The use of a filler is not all that clear-cut, pun intended. On top of the added weight, you must also consider the reduced case volume. With a fluffy filler, like dacron, the actual compressed volume is quite small, but with more solid fillers like CoW, BPI or thick felt wads you must reduce the load accordingly - just as you would when seating the bullet deeper.

I've been experimenting with paper mache wads lately in my 45-70, and while they gives more uniform speeds with slower powders, they also raise pressure significantly compared to fluffy fillers.

[onondaga]

There are a couple of side bar advantages with certain fillers. The BPI manufacturer claims their product also acts as a quasi gas check and will extend the possibility of increasing load velocity and gaining accuracy. I have found that to be very true with plain base boolits and BPI.

Precision Reloaders Spherical Buffer claims to also clean the bore well and remove lead as you shoot. I find that to be believable and it shoots clean but cream of wheat or corn grits will also do that very well.

COW and grits weigh about 2X per volume as PR buffer. PR buffer weighs about 2X per volume as BPI.

Dacron used correctly is about 15X lighter than BPI. That should also be helpful information for selecting a buffer if you choose to..

The heavier fillers also can make a notable difference in adding recoil.

IMR Trail Boss is an excellent selection without filler if it will get you the velocity you are seeking, but beware that at near capacity loads and above that pressures sky rocket dramatically and can easily get dangerous with this lightening fast powder.



Gary

[Bullshop]

When I feel the need to use a filler I use packing popcorn.

[Larry Gibson]

209Jones

Try reading the sticky at the top of this forum titled "fillers". You will find lot's of info in how to use dacron including how to determine how much to use.

I've used dacron in numerous large 45 cal cartridges. I'd suggest getting some "batting" from the loacal fabric store and cut squares into 1, 1 1/2 and 2 gr. Cut a strip off the batting sheet about 1" wide and then you can easily just eyeball the width for c lose to the correct amount needed. You do not have to weigh it, eyeballing works very well with the key being to used enough so it just fills the air space between the powder and the bullet. Compression is not needed.

You don't mention the powder to be used but I suggest 4895. It works very well in 45-110s with 1 1 1/2 gr dacron filler under 500+ gr bullets.

Larry Gibson

[Bulltipper]

I have been making cat sneeze rounds for my suppressed .308 Savage model 10 and was concerned about hanging up the filler (Dacron) in the can. I was removing the bolt and having a look down the barrel after every shot, I couldn't bring myself to not look. I decided to try an experiment with filler, and went down to my local magic shop specialty store and picked up a package of flash cotton (nitrated cotton) This stuff has the consistancy of regular cotton but burns super fast. I did some compatibility testing with the pistol powder I use and had no reaction. I made up a cartrige with one of my known to work recipes and used 1/2 grain of flash cotton pressed down in the end of the case to keep the powder up against the primer. I then used a bit of One Shot case lube on the jacketed 180 grain bullet for lube. What had previously been a slightly subsonic round (1030fps) now fired at slightly supersonic (1200fps) and burned clean as a whistle, no material came out the barrel after the bullet. I lowered the load a tiny bit and was able to get the subsonic performance I was after. I have shot a few hundred of these now and they are working flawlessly. Any thoughts from the gallery?

[Larry Gibson]

What's the cost of "flash cotten"?

Larry Gibson

[Bulltipper]

The package was $7 and it was about 4" x 6" x 3/8" thick. I think I will get about 300 to 400 loads per package.

[Cap'n Morgan]

Any thoughts from the gallery?

I think your flash cotton is actually gun cotton. That would explain your increased speed; you added half a grain of ultra fast burning powder to your load.

BTW: Gun cotton is fairly easy to make yourself, but at the price you mention it's hardly worth the trouble.

[Bulltipper]

Cap'n Morgan, I agree with you, I was first thinking about using flash paper and during my research I found they make flash cotton which I figured was similar to or the same as the gun cotton developed during the evolution of nitrocellulose gunpowder. The cotton wads up in the bottom of the case quite nicely, and though it doesn't take up airspace, it negates the need for magnum primers and oversizing the flash hole for proper ignition.