I suppose in some things, I am a perfectionist. I have loads for all the calibers I shoot, but one thing that has bothered me is the extreme spread I get from each of my loads. I have used toilet paper filler for several years in an effort to get more consistent burning by keeping the powder against the primer. Toilet paper, loosely rolled and folded, is less than ideal, as powder can still work its way in between the folds and not get burned.
In the Summer 2011 issue of The Double Gun Journal, Sherman Bell published the results of pressure testing using a variety of fillers. Cream of Wheat and stacked hard felt wads gave the highest pressure increases, while cotton and kapok gave the lowest. Why fillers you ask? Cartridges that were originally designed for black powder will often have a lot of empty space when using smokeless powders. The simple solution is to use black powder but what does a fellow do if he wishes to use smokeless? I have a few rules of thumb, two of the most important of which are:
1. Always stick with original black powder ballistics (same bullet weight and velocity)
2. Always use smokeless powders that have the same or lower peak pressures as black powder (powders with a burn rate slower than Blue Dot)
If a fellow sticks to these two rules, he will get peak pressures and pressure curves that are the same as or lower than black powder peak pressures.
I decided to use cotton as the local fabric store did not have kapok. I bought just under a pound. My quest is to re-do all my loads, this time using cotton filler to reduce E.S. (extreme spread) and reduce group size. My first project was the 44-40. With a little experimentation, I settled on 17.7 grains of 5744 with a pinch of cotton between the powder and the base of the seated bullet, which is an Accurate Mold 205 grain gas check design. The photo below shows a bullet (not yet wiped clean of excess lube), a typical pinch of cotton (just enough to nicely fill the space between the powder and the bullet with about 50% compression of the cotton) and the case.
Twelve rounds over the chronograph showed a muzzle velocity of exactly 1,300 fps with an E.S. of 28 fps and a S.D. of 8 fps.
Range Test
Today, I tried the load out at 100 yards. My rifle is an original Winchester Model 1873, received in the Winchester warehouse on August 1, 1889 and shipped on September 18th, 1889. Here is a photo of the old classic ...
I had loaded up ten rounds but had forgotten that I had left the rear sight set at 150 yards, so the first shot hit just above the paper. I adjusted down one notch and fired my first five rounds. Four of them went into a 2" group at 100 yards, with the fifth shot hitting a bit low. I know exactly why that fifth shot hit low ..... the corners of the rear sight notch are blurry to my 57 year-old eyes and it is very easy to mess up on elevation if one is not very careful. Here is a photo of the target used for the first five shots ....
I had four rounds left, so put up a new target and, this time, paid special attention to keeping the same elevation in the blurry rear sight notch. I got a four-shot group of 2 & 1/8" at 100 yards. Here's a photo of the target ....
I'm happy. This load is a keeper. It is accurate (as my old eyes will allow with open iron sights) and it burns consistently, as evidenced by the relatively low E.S. My next project is to develop a cotton filler load for my 38-72, starting next week.
In the Summer 2011 issue of The Double Gun Journal, Sherman Bell published the results of pressure testing using a variety of fillers. Cream of Wheat and stacked hard felt wads gave the highest pressure increases, while cotton and kapok gave the lowest. Why fillers you ask? Cartridges that were originally designed for black powder will often have a lot of empty space when using smokeless powders. The simple solution is to use black powder but what does a fellow do if he wishes to use smokeless? I have a few rules of thumb, two of the most important of which are:
1. Always stick with original black powder ballistics (same bullet weight and velocity)
2. Always use smokeless powders that have the same or lower peak pressures as black powder (powders with a burn rate slower than Blue Dot)
If a fellow sticks to these two rules, he will get peak pressures and pressure curves that are the same as or lower than black powder peak pressures.
I decided to use cotton as the local fabric store did not have kapok. I bought just under a pound. My quest is to re-do all my loads, this time using cotton filler to reduce E.S. (extreme spread) and reduce group size. My first project was the 44-40. With a little experimentation, I settled on 17.7 grains of 5744 with a pinch of cotton between the powder and the base of the seated bullet, which is an Accurate Mold 205 grain gas check design. The photo below shows a bullet (not yet wiped clean of excess lube), a typical pinch of cotton (just enough to nicely fill the space between the powder and the bullet with about 50% compression of the cotton) and the case.
Twelve rounds over the chronograph showed a muzzle velocity of exactly 1,300 fps with an E.S. of 28 fps and a S.D. of 8 fps.
Range Test
Today, I tried the load out at 100 yards. My rifle is an original Winchester Model 1873, received in the Winchester warehouse on August 1, 1889 and shipped on September 18th, 1889. Here is a photo of the old classic ...
I had loaded up ten rounds but had forgotten that I had left the rear sight set at 150 yards, so the first shot hit just above the paper. I adjusted down one notch and fired my first five rounds. Four of them went into a 2" group at 100 yards, with the fifth shot hitting a bit low. I know exactly why that fifth shot hit low ..... the corners of the rear sight notch are blurry to my 57 year-old eyes and it is very easy to mess up on elevation if one is not very careful. Here is a photo of the target used for the first five shots ....
I had four rounds left, so put up a new target and, this time, paid special attention to keeping the same elevation in the blurry rear sight notch. I got a four-shot group of 2 & 1/8" at 100 yards. Here's a photo of the target ....
I'm happy. This load is a keeper. It is accurate (as my old eyes will allow with open iron sights) and it burns consistently, as evidenced by the relatively low E.S. My next project is to develop a cotton filler load for my 38-72, starting next week.
