When loading light loads, like less than half a case of powder, a big controversy is always whether to use a filler, to hold the powder tight against the primer.
Sometimes I've thought a filler improved groups, while other times I've thought it just to be a waste of time. I did some testing today with the chronograph and while it is no where near enough shooting to prove a point, the little shooting I did certainly favoured using a filler.
With the 45-70 I loaded four rounds with 420 grain flat base cast bullet, charged with 24.5 grains of 4227 and no filler.
Then I loaded four more just the same, only used that light cotton they use as fillers in pill bottles, stuffed tight onto the powder.
These loads were nearly 200 fps slower than I thought they would be, judging from adapting some changes from the figures given in the Lyman book.
I shot the no filler loads first, with the first shot being from a oiled barrel, so in all fairness, we won't figure in the first shot. But here they are.
997, 1080, 1032 and 1177.
By not figuring in the first shot, we get an average of 1096 from the other three, with an es of 145.
Here are the four with fillers.
1147, 1088, 1154 and 1161.
These four averaged 1137, with an es of 73.
This would indicate that Johnn, and all the others who believed in using a filler, may just have been right! And Johnn, somewhere in my house is a few feet of the round door seal material left over from what I used before, after you put me onto it. Just got to find it!
I used this rifle for the testing.
Bruce

Sometimes I've thought a filler improved groups, while other times I've thought it just to be a waste of time. I did some testing today with the chronograph and while it is no where near enough shooting to prove a point, the little shooting I did certainly favoured using a filler.
With the 45-70 I loaded four rounds with 420 grain flat base cast bullet, charged with 24.5 grains of 4227 and no filler.
Then I loaded four more just the same, only used that light cotton they use as fillers in pill bottles, stuffed tight onto the powder.
These loads were nearly 200 fps slower than I thought they would be, judging from adapting some changes from the figures given in the Lyman book.
I shot the no filler loads first, with the first shot being from a oiled barrel, so in all fairness, we won't figure in the first shot. But here they are.
997, 1080, 1032 and 1177.
By not figuring in the first shot, we get an average of 1096 from the other three, with an es of 145.
Here are the four with fillers.
1147, 1088, 1154 and 1161.
These four averaged 1137, with an es of 73.
This would indicate that Johnn, and all the others who believed in using a filler, may just have been right! And Johnn, somewhere in my house is a few feet of the round door seal material left over from what I used before, after you put me onto it. Just got to find it!
I used this rifle for the testing.
Bruce




















































