Today, a young fellow came over to discuss an issue with his handloads.
He was getting huge velocity deviations between shots. Anywhere from 75-125 fps.
The cartridge he was loading was the venerable old 30-06, with 165-grain Hornady IL flat base Spire Point bullets.
He was using CCI200 primers in once-fired cases and 44 grains of H335. This powder is OK for this load but IMHO, not the best.
I remembered an article written by George C. Nonte, who passed on back in 1978.
Mr Nonte was a very outspoken gentleman. He and Elmer Kieth loved to get at each other, very respectfully of course.
They both came from very different backgrounds and had similar gritty personalities, but they were both walking/talking encyclopedias, very willing to give that knowledge to anyone who asked in a polite manner.
Mr Kieth was a cigar smoking/chewing cowboy in his early years and Mr Nonte went to West Point and graduated. Mr Keith was much older than Mr Nonte and was cowpoking around the time Mr Nonte was born.
Mr Nonte rose to the rank of major and was posted to the Ordnance Corp.
One of his projects was to establish loads for different cartridges used by the US Army.
There were all sorts of issues to deal with and he had to deduce why certain powders wouldn't work with specific bullet/cartridge case/primers under all conditions and come in at or under specified costs, while still maintaining specified velocities and accuracy.
One thing that stumped them for a long time was that certain powder blends, such as 4064, 3031, or BLC would give them radical velocity deviations between shots.
They had a very good idea why it was happening, but it was Mr Nonte's job to prove it.
Folks like you and I mostly worry about the cost of a few pounds or kegs of powder and a few thousand primers, etc.
For Mr Nonte, that was a pittance, when he had to come up with a compilation of components that would deliver specified performances, within his cost-per-delivered round parameters, as set by the Ordnance board's budget.
One of the major expense factors was the graphite coating used in the coatings of the powder granules, which controlled the burn rate and how much powder would be used in each case.
He had to balance all sorts of costs, such as case thicknesses which could be varied to use faster, less bulky blends of powder, and which combination would be cheaper but still within specified parameters all around.
What they found was a cartridge case needed to be at least 85% full of powder to achieve the velocity deviations they deemed acceptable; with the bullets they were using at the time.
BLC was a very cheap and easy powder to produce, however, in its trial stages it didn't fill the case enough while achieving the velocities required.
They were always getting unacceptable velocity deviations, not just from lot to lot but within the lots as well.
They determined the charge of BLC wasn't filling the case enough and causing erratic burns, because of excessive air space in the cartridge.
Depending on the position of the rifle, burn rates increased or decreased depending on how close the powder was to the primer.
It eventually led to the production and acceptance of BLC2, which we're familiar with today.
My young friend had a problem getting his head around this, so we pulled the bullets from the remaining cartridges, stuffed a grain of Dacron fiber over the powder, and then seated the bullets again.
He took them back to the range, only a klik away, shot them and his velocity spreads came down to an appx average of 25fps. The accuracy was much better.
This isn't a common issue these days, but it can and does still happen, especially with loads close to minimum.
I just thought I should throw this out there. I don't see much of this issue, but maybe some of you may have come across it as well.
He was getting huge velocity deviations between shots. Anywhere from 75-125 fps.
The cartridge he was loading was the venerable old 30-06, with 165-grain Hornady IL flat base Spire Point bullets.
He was using CCI200 primers in once-fired cases and 44 grains of H335. This powder is OK for this load but IMHO, not the best.
I remembered an article written by George C. Nonte, who passed on back in 1978.
Mr Nonte was a very outspoken gentleman. He and Elmer Kieth loved to get at each other, very respectfully of course.
They both came from very different backgrounds and had similar gritty personalities, but they were both walking/talking encyclopedias, very willing to give that knowledge to anyone who asked in a polite manner.
Mr Kieth was a cigar smoking/chewing cowboy in his early years and Mr Nonte went to West Point and graduated. Mr Keith was much older than Mr Nonte and was cowpoking around the time Mr Nonte was born.
Mr Nonte rose to the rank of major and was posted to the Ordnance Corp.
One of his projects was to establish loads for different cartridges used by the US Army.
There were all sorts of issues to deal with and he had to deduce why certain powders wouldn't work with specific bullet/cartridge case/primers under all conditions and come in at or under specified costs, while still maintaining specified velocities and accuracy.
One thing that stumped them for a long time was that certain powder blends, such as 4064, 3031, or BLC would give them radical velocity deviations between shots.
They had a very good idea why it was happening, but it was Mr Nonte's job to prove it.
Folks like you and I mostly worry about the cost of a few pounds or kegs of powder and a few thousand primers, etc.
For Mr Nonte, that was a pittance, when he had to come up with a compilation of components that would deliver specified performances, within his cost-per-delivered round parameters, as set by the Ordnance board's budget.
One of the major expense factors was the graphite coating used in the coatings of the powder granules, which controlled the burn rate and how much powder would be used in each case.
He had to balance all sorts of costs, such as case thicknesses which could be varied to use faster, less bulky blends of powder, and which combination would be cheaper but still within specified parameters all around.
What they found was a cartridge case needed to be at least 85% full of powder to achieve the velocity deviations they deemed acceptable; with the bullets they were using at the time.
BLC was a very cheap and easy powder to produce, however, in its trial stages it didn't fill the case enough while achieving the velocities required.
They were always getting unacceptable velocity deviations, not just from lot to lot but within the lots as well.
They determined the charge of BLC wasn't filling the case enough and causing erratic burns, because of excessive air space in the cartridge.
Depending on the position of the rifle, burn rates increased or decreased depending on how close the powder was to the primer.
It eventually led to the production and acceptance of BLC2, which we're familiar with today.
My young friend had a problem getting his head around this, so we pulled the bullets from the remaining cartridges, stuffed a grain of Dacron fiber over the powder, and then seated the bullets again.
He took them back to the range, only a klik away, shot them and his velocity spreads came down to an appx average of 25fps. The accuracy was much better.
This isn't a common issue these days, but it can and does still happen, especially with loads close to minimum.
I just thought I should throw this out there. I don't see much of this issue, but maybe some of you may have come across it as well.
