Should I use a filler

[220]

All the success people are having has got me wondering if I should be using a filler in some loads.
Currently working on a load for my sons 375H&H, using a NOE mould that throws a HP at 266gr and AR2207 (H4198)
Getting up to 100fps velocity variation but 3 shot groups at 100y are 1-1.5"
At 35gr and 1650fps so short of our 2000fps velocity aim and Im thinking the variation might reduce as we continue to work up.
Would you go with a filler from the start or see what happens and try a filler if the results aren't up to standard.

[Larry Gibson]

Would you go with a filler from the start or see what happens and try a filler if the results aren't up to standard.

I would do both which is exactly what I did with 4227,H4198 and AA5744 in my own M70 three six bits with a 270 gr cast 375449. Found a good load with the AA5744 w/o the filler (Dacron) that does as well as the other two powders which benefitted from the fillers.

Larry Gibson

[220]

Thanks Larry
Seems that we are thinking similarly in that if I can find a load that works without filler loading is a bit simpler.
New rifle and haven't got a good supply of brass yet so the amount of loading/testing we can do in one go is limited.
Accuracy is acceptable the pic below shows the last 2 loads tested, using a crohno and spotter so I know which shots are which.
On the 2 cast targets the shots touching were within 15fps the one on its own around 100fps faster. The factory target for comparison, the shot out on it may well have been me, factory H&H loads off the bench do take a little work to shoot.
http://madmick3006.com/ahngallery/upload/files/2014-08/436b13f5.jpg

[sthwestvictoria]

Would you go with a filler from the start or see what happens and try a filler if the results aren't up to standard.

I had the same queries with my 35 whelen and the 250grain CBE. I was using AR2206H rather than 2207 but got similar variance at low loads. Rather than add a filler I just pushed the loads up. I am using oven heat treated WW so they have stood velocity well. My most accurate load now is at 1890fps. At those 1600fps velocities the load will certainly take a bit more powder without being too fast.

[303Guy]

I would personally never use a load with empty space in a the case without a 'filler'. I don't consider Dacron to be a filler - it's a powder positioner. It takes up very little space in the case but it does hold the powder against the primer. It may even prevent chamber ringing.

[Larry Gibson]

303guy

By "It takes up very little space in the case but it does hold the powder against the primer." are you referring to space occupied or that the fluffiness still has a lot of "air" in it?

I refer to "filler" as anything occupying all the space between the powder and base of the bullets. Some fillers are more "solid" than others. While a "powder positioner" the filler also decreases case volume (increasing ignition and burning consistency and raising the psi a bit) and does not loosen and move forward in the case from recoil preventing powder migration and hangfires.

A "wad" is a "powder positioner" holding the powder against the primer but does not occupy all the space between the powder and the base of the bullet.

Larry Gibson