Dacron (polyfill) Extra Loft or Regular

[DonMountain]

I have never used fillers for rifle cartridges before using heavy cast lead boolits and medium speed burning powders. I have been working on loads using a LEE 8mm KARIBINER boolit weighing about 230 grains cast out of wheel weights and gas checked in a longer barreled Turk converted GEW 88 rifle. From recommendations I found here, I have been using IMR-4895 powder and would like to try using a filler to improve the top end velocities for deer hunting and long range target shooting. So I stopped by the WalMart store looking for 5/8" thick batting as recommended by Larry in his pointers. So how is this dimension related to the bags of quilt batting sold under the "Extra Loft" or "Regular" descriptions? Does it make a difference and I should just figure out how big a piece is the 1/2 grain or 3/4 grain size I need to fill the case up to the base of the boolit?

[runfiverun]

it don't matter.
just get enough in there to hlod the powder down and touch the boolits base
.5 or .6 isn't a big deal.

[DonMountain]

Ok, I bought a bag of each, the Extra Loft and the Regular, and started cutting out squares of different sizes to get what I need. And of the first bag I opened, 1/2" square was about 0.5 grains, a 3/4" square is about 0.75 grains, and a 1" square is about 1.5 grains. So I am off and running with a 3/4" square in an 8mm Mauser case over 30 grains of IMR-4895 and under a LEE 8mm KAR 239 grain gas-checked boolit for my first range test.

[Larry Gibson]

That's how I do it; have sizes cut to 1/4 gr from 1/2 to 1 1/2 gr and then just eye ball it as I cut. My tests, accuracy, velocity and pressure, have shown that the trick is to get enough to fill the space between powder and bullet. Not enough is not good, a little too much makes no difference but too much as in stuffing it in and compacting it can raise pressures some but mostly isn't good for accuracy. Just enough to fill the space with mabe the bullet compressing it a tudge when seated is just right.

Larry Gibson

[DeadHandRed]

i loaded up two batches of 7.62x54r (21 grains of 4227, 200 grain boolit) that shot with no difference. 1 grain of filler and 1.5 grains filler. if you shook the 1 grain batch you could hear the slightest movement of powder.. 1.5 grains had no movement.