ohland
07-06-2015, 03:15 PM
In the dark days of the early cupro-nickel jackets, the bores got pretty ugly fast. One response was to grease the bullets... There are little grease applicators, a simple tube closed at one end, filled with grease, and the other being open to allow the bullet to be placed into it.
This metallic fouling was answered in two ways, first, the addition of tin in the IMR "1/2" series of powders, the second being improvements in the jacket material.
American Rifleman, vol 68, No. 17, April 15, 1912 - pages 3-5, 10, 11
https://books.google.com/books?id=MJkwAQAAMAAJ&pg=PA401&dq=.40+caliber+bullet&hl=en&sa=X&ei=J7-aVeOqA4WBygSFoYSwAg&ved=0CFkQ6AEwBw#v=onepage&q=.40%20caliber%20bullet&f=true
Grease
By Capt. Edward C. Crossman
THE War Department Board for the selection of arms and ammunition for the National Matches of 1921 and for the Palma Rifle Team, if such an animal there be, decided in solemn conclave, all being present and in their right minds, to put the kibosh on the use of grease as a flavoring for the ammunition of the service rifle.
The board legislated against its use in the machine rest test of ammunition to be held in May, and after various discussion as to who was to bell the cat, decided to use its efforts to discourage the use of grease at the National Matches.
Of course, it is true that to discourage its use by some of the hard~boiled brotherhood, firing their own pet rifles, the use of a club would be indicated, and it was in recognition of this fact that the board decided to try moral suasion rather than to ask the powers to take action.
The facts that moved the board to take the action it did were that careful test had demonstrated dangerously high pressures to result from the careless use of grease, while grease always ran up the thrust on the bolt head and thus increased the danger from cracked lugs or a soft case, both of which unfortunately happen in the best of regulated factories.
Likewise, observation by persons not afflicted with the grease delusion showed that in the hands of anyone but the very careful rifleman, bullet lubricant often became a neat mixture of dust and grease, elegantly adapted to grinding motor valves but not to lubricating a rifle barrel by any stretch of the imagination. The classes at Camp Benning of the year 1919 used grease. Also the wind blew merrily, and the soil of Jojaw got up and moved from hither to yon—yon sometimes—oftimes as a matter of fact—-meaning the empty Tuxedo can which had been put to a nobler purpose as a container for mobile lubricant or Acme cup or some other grease.
Nothing discouraged, the hopeful West Pointer would then push a clip of cartridges into said can, withdrawing it nice and gooey, and would then push the clip into the rifle. Sometimes a more than careful youth would take a finger and daub the grease about a bit to get a better distribution. Not by any stretch of the imagination could a mixture of cup grease and Georgia dirt aid in lengthening the life of a rifle barrel and in keeping down metal, but easy to imagine is the increase of pressures by the introduction of a few spoonfuls of grease into a chamber intended for the cartridge alone.
Not being an instructor, but an officer of the experimental department, this was none of my party; but I took occasion to watch the proceedings both at Camp Perry and at Camp Benning and decided then and there that as an average deal the use of grease was more harmful than beneficial. Also——because Major Critchfield used to sit down in hunks of it that were always liberally plastered on the benches at Perry, and then would arise and speak a piece about the man who first started the habit, several words of which were not profane—because of this, grease is responsible for at least one poor erring human back-sliding from all the religion he ever had.
Aside from its tendency to keep down metal fouling in the days when metal fouling used to vex, grease is largely a superstition. I was one who used to plaster it on each and every bullet I shot through my rifle, not because I knew or believed it did any good, but because it sort of sounded nice and cosy to think that I was helping the bullet to slide through the bore of my nice rifle without wearing it out. I was enjoying a seance at the great American sport of kidding myself.
I’ve never seen, heard, felt or smelled any proof that grease cut down barrel wear or lengthened its life. I’ve seen, heard, felt and smelled statements that it did, but never any proof. I’ve been told by gentlemen who in dubitably believed it that the use of grease kept the bore in better shape because they used grease in a particular rifle and it was in nice shape. They did not say that they had taken another rifle of practically the same run of steel and shot it without grease to see if it also would stay “in nice shape.” Cold-blooded experimenters have no business in the rifle game; they take all the romance out of it, dog-gone ’em.
In these days metal fouling troubles but little, and intensive experiments are under way with the foreign artillery discovery of tin, lead and zinc, to find the best way to apply it to exorcise this old trouble of the rifleman's. The last excuse for cup grease is nearly gone, except possibly when cartridge companies load nitroglycerine powders behind 180-grain bullets.
It is true that experiments by the Marines in 1913 seemed to prove that the use of grease without cleaning at all during the summer's shoots gave more consistent accuracy and slightly longer life, but they had two experiments wrapped up into one, and the average rifleman is not going to let his pet go uncleaned over night as did the Marines.
The little joker as to why they could let their rifles go uncleaned as they did is explained in two ways. The first is the nature of what we have loosely referred to as grease, Diving into a book on motor cars the other day to find what grease was, I was much surprised to find that it was nothing but soap thoroughly impregnated with a mineral oil. This, it is stated, is the general makeup of what is known as cup grease, and which classification takes in mobile lubricant and Acme cup and others used by riflemen.
Now, if you take soap, impregnate it with mineral oil and one other ingredient, you have B. S. A. Saftetipaste, the most successful barrel preservative on the market. Wherefore the Marines’ freedom from the demon rust in their rifles.
The other reason is that they didn’t give two whoops, because rarely does a Marine ever use the same barrel two consecutive shooting seasons.
In spite of all this, and that I have never had a gent look me in the eye and tell me that he knew positively of a case where two rifles of the same lot of barrel steel, and the same star gauging, were shot until one of them wore out; one of them used with grease, the other without. This is the only proof of the pudding, and such proof has never been made. All we ever get is conflicting personal opinions under different conditions and with estimated amounts fired through the rifles, which is proof as positive as that advanced by Pappy Lodge as to the materialization of spirits.
When an officer of the Small Arms Ballistic Station in Florida, which was established to conduct experiments with machine guns and machine rest for ballistic purposes, I suggested to Colonel Wilhelm that Frank ford be requested to load about 12,000 rounds of ammunition having a narrow band of wax and graphite where the bullet joined the case, and another lot with the entire bullet coated with this composition. This is the old Ross formula for match ammunition.
The lots were alike, in being loaded with the model of 1909 boat-tail bullet and a certain lot of powder not on the market, but with which we were familiar as to erosion results.
Both lots were fired in March of 1920. The lot with the narrow band, simulating in amount the grease put on by the careful rifleman, wore out the barrel in 7,900 rounds of firing through the machine gun.
The lot completely coated over went 9,700, but neither showed any particular addition to the barrel life noted with the dry bullets and the same powder and 2,600 f. s. velocity. The difference in the two lots was that noted in many rests with precisely the same ammunition.
What wears out a machine gun or rifle barrel is of course apparent to anyone who has followed the subject of small arms—merely powder gas erosion. The proportion of bullet wear to powder gas washing is so low that the reduction of the bullet wear to nothing probably would not length en the barrel life 10 per cent. The lesson was plain in observing the effect of two different kinds of powder.
One sort wore out the barrel by putting scooped-out places in the bore just forward of the lead and roughening up the bore and washing off the lands, but all within the first eight inches of barrel.
The other sort, coated and slow burning, did not injure the bore noticeably at any one spot, but washed away the lands the entire barrel length. It was plain to the eye and checked up with the star gauge and plugs.
There must be, of course, a slight wear of the lands at the bullet entrance, because they act as a die to size the bullet to form and shape, but this is restricted to the first inch, and the effect is so quickly covered up by the harsher effect of the powder gas that no rifleman ever saw it by itself. Wherefore it is obvious that grease can do nothing for a barrel but slightly reduce bullet friction and thus help to keep down metal fouling.
All this is considering the beneficial effect of grease. A phase of it I have not touched on is one of the ways that are dark but useful, nevertheless, in rapid fire. This is merely to rub a grease-coated finger over the bodies of the cartridges of the first clip to go into the rifle. Without question, it runs up the bolt-head thrust, and likewise, without question, it makes the cases extract easier and permits that smooth mechanical throw of the bolt that makes for ten waves of the white paddle.
The chronograph and thousand-yard shooting from the Mann rest both prove that grease does not raise the velocity of the bullet as it leaves the bore, and therefore its reduction of friction is not one that is susceptible of measurement. I tested greased and ungreased ammunition repeatedly at Daytona at 1.000 yards from the Mann rest and never found the slightest difference in point of impact. If you fire ten without grease and then with grease at 1,000 yards, they will intermingle until you cannot tell one from the other.
This was with the bullet carefully and sparingly greased and the chamber kept dry.
When grease does raise the velocity is when it raises the pressure, but this does not prove that its heightened velocity is a result of lessened friction; it is merely equivalent to a heavier load.
Two years ago I was sent on a trip through the arms plants and arsenals from Camp Benning on orders which had been asked for from Camp Perry before the armistice. For this trip I have my good friend Colonel Mumma to thank. Its purpose was to become familiar with manufacturing processes and to study the experimental methods of the various plants visited. The trip, being made on orders that were rather of the blanket variety, permitted visiting for a short time some plants not on the orders, and full advantage was taken of the chance. In the two months practically every arms plant, Government and private, and every ammunition factory on the Atlantic seaboard was visited.
One of the things which had long aroused my curiosity was the performance of grease under the cold eye of the pressure gun and the chronograph.
Wherefore, arriving at Springfield and being made welcome to the experimental department by my friend Major Fiala, one of the things I asked for was a show-down of the grease question.
We had no straight mobile lubricant, so used a mixture of sperm oil and cosmic, which gave a nice slippery mixture. The first verse was with the bullet and neck greased as they are when poked into a can of grease as the average rifleman does the trick. Two shots of the ammunition
we were to use, fired dry, gave a mean of 47,000 pounds velocity; instrumental. 2,655, equal to 2,695 muzzle.
Neck and bullet greased gave a minimum pressure of 51,100; maximum, 60,600; velocity, minimum, 2,757; maximum, 2.804.
Case and bullet given thin, even coat: High pressure, 52,100; low, 47,100; high velocity, 2.800; low, 2,700. This velocity was inconsistent with the pressures, but both were lower than with gobs of grease on the case neck.
Bullet greased carefully, none on case: High pressure, 54,600; low. 49,100: high velocity, 2.777; low, 2,744.
So we called it a day and passed on to chronographing the model 1917 rifle about which I had been curious.
When I got over to Frankford I got my old friend George Schnerring to repeat the grease test, using mobile lubricant. Frankford being an ammunition factory, making the crushers for test at other arsenals and establishing the standard, ought to be entirely reliable as to the ballistic results obtained.
So the gun roared and the weight fell into the dash pot full of beans, and the crusher got pushed into itself. Four shots of standard ammunition, Frankford service of 1919 loading, gave the following—fired dry, of course: Pressure. 47,700, 50,700, 48,600. 49,400 x velocity 2,610, 2,637, 2,616, 2.625, instrumental, to which add 60 f. s. for muzzle, as they take their velocities over a 150-foot range. In other words, the high pressure was 50,700; low, 47,700; difference, 5,000 pounds. Difference in velocity, 27 feet, with 2,637 the high figure. Now let's see how the story ran after the dark villain came into the plot.
Five shots, bullets greased by twirling them up to the neck of the case in the lubricant
51,200 _____________ __ 2,667
63,100 _____________ __ 2,804
56,750 _____________ __ 2,753
65,470 _____________ __ 2,849
54,550 _____________ __ 2,740
Five shots, bullet and case greased:
50,350 _____________ __ 2,706
44,900 _____________ __ 2,656
49,700 _____________ __ 2,657
48,400 _____________ __ 2,670
55,160 _____________ __ 2,753
As the Springfield test showed, pressures were increased more by grease in plenty around the neck of the case than by a thin, even coating on the entire case. As I applied the grease myself, I know just how it was done.
So, as the cold figures show, taken by expert chronograph and pressure gun men, grease applied by the common or garden variety of poking bullet and neck of case into the can, gave a high pressure of 65,470 pounds and a high velocity of 2,849, equal to 2,909 muzzle. The pressure varied 14,000 pounds and the velocity 182 f. s. Isn't that a pretty dish to set before the king?
With a thin coat over the bullet and case, simulating the usual nice oiled chamber after a few shots on a hot day, high pressure was 55,160; low, 44,9900; variation, 10,260; high velocity, 2,753; low, 2,656; difference, 97 f. s. A peculiarity of this test was the one low pressure with velocity still up to normal.
If the case is left dry, the pressure registered this way is comparatively little, giving an effective example of the way bolt head thrust is increased by the greasy chamber that invariably follows the ordinary rifleman's method of using the lubricant
Eight years ago in “Outer's Book" of Milwaukee I pointed out this little joker in the use of grease, and the likely connection with had with the flock of cracked bolt lugs at Perry in 1913. It develops the maximum possible bolt-head thrust, because the wall of the case does not cling to the chamber walls, and the case sits down hard on the bolt. It is a close parallel to the unfortunate accident told of by the poet:
“There was a young lady named Anna,
Who stepped on a ripe old banana,
She lit on the street,
But not on her feet,
And now she can't play the piana."
The whole trouble in this happening was that the banana eliminated the friction between the young lady's foot and the pavement, just as grease in the chamber eliminates it between chamber and case.
The Du Pont figures being more assuring to the Grecians than those of the arsenals, I decided, if possible, to get the Frankford Arsenal to settle the matter by official test, and to that end suggested to the C. O. of the Infantry School of Arms at Camp Benning to write, asking for a full and detailed test of the grease business. I asked that figures be obtained, first, for the dry cartridges to show the variation to be expected in velocity and pressure; second, for the cartridges twirled to the necks in a can of grease a la the favored way of applying it by the hoi poloi, and, third, for the cartridges with a thin coat of grease on the bullet.
This metallic fouling was answered in two ways, first, the addition of tin in the IMR "1/2" series of powders, the second being improvements in the jacket material.
American Rifleman, vol 68, No. 17, April 15, 1912 - pages 3-5, 10, 11
https://books.google.com/books?id=MJkwAQAAMAAJ&pg=PA401&dq=.40+caliber+bullet&hl=en&sa=X&ei=J7-aVeOqA4WBygSFoYSwAg&ved=0CFkQ6AEwBw#v=onepage&q=.40%20caliber%20bullet&f=true
Grease
By Capt. Edward C. Crossman
THE War Department Board for the selection of arms and ammunition for the National Matches of 1921 and for the Palma Rifle Team, if such an animal there be, decided in solemn conclave, all being present and in their right minds, to put the kibosh on the use of grease as a flavoring for the ammunition of the service rifle.
The board legislated against its use in the machine rest test of ammunition to be held in May, and after various discussion as to who was to bell the cat, decided to use its efforts to discourage the use of grease at the National Matches.
Of course, it is true that to discourage its use by some of the hard~boiled brotherhood, firing their own pet rifles, the use of a club would be indicated, and it was in recognition of this fact that the board decided to try moral suasion rather than to ask the powers to take action.
The facts that moved the board to take the action it did were that careful test had demonstrated dangerously high pressures to result from the careless use of grease, while grease always ran up the thrust on the bolt head and thus increased the danger from cracked lugs or a soft case, both of which unfortunately happen in the best of regulated factories.
Likewise, observation by persons not afflicted with the grease delusion showed that in the hands of anyone but the very careful rifleman, bullet lubricant often became a neat mixture of dust and grease, elegantly adapted to grinding motor valves but not to lubricating a rifle barrel by any stretch of the imagination. The classes at Camp Benning of the year 1919 used grease. Also the wind blew merrily, and the soil of Jojaw got up and moved from hither to yon—yon sometimes—oftimes as a matter of fact—-meaning the empty Tuxedo can which had been put to a nobler purpose as a container for mobile lubricant or Acme cup or some other grease.
Nothing discouraged, the hopeful West Pointer would then push a clip of cartridges into said can, withdrawing it nice and gooey, and would then push the clip into the rifle. Sometimes a more than careful youth would take a finger and daub the grease about a bit to get a better distribution. Not by any stretch of the imagination could a mixture of cup grease and Georgia dirt aid in lengthening the life of a rifle barrel and in keeping down metal, but easy to imagine is the increase of pressures by the introduction of a few spoonfuls of grease into a chamber intended for the cartridge alone.
Not being an instructor, but an officer of the experimental department, this was none of my party; but I took occasion to watch the proceedings both at Camp Perry and at Camp Benning and decided then and there that as an average deal the use of grease was more harmful than beneficial. Also——because Major Critchfield used to sit down in hunks of it that were always liberally plastered on the benches at Perry, and then would arise and speak a piece about the man who first started the habit, several words of which were not profane—because of this, grease is responsible for at least one poor erring human back-sliding from all the religion he ever had.
Aside from its tendency to keep down metal fouling in the days when metal fouling used to vex, grease is largely a superstition. I was one who used to plaster it on each and every bullet I shot through my rifle, not because I knew or believed it did any good, but because it sort of sounded nice and cosy to think that I was helping the bullet to slide through the bore of my nice rifle without wearing it out. I was enjoying a seance at the great American sport of kidding myself.
I’ve never seen, heard, felt or smelled any proof that grease cut down barrel wear or lengthened its life. I’ve seen, heard, felt and smelled statements that it did, but never any proof. I’ve been told by gentlemen who in dubitably believed it that the use of grease kept the bore in better shape because they used grease in a particular rifle and it was in nice shape. They did not say that they had taken another rifle of practically the same run of steel and shot it without grease to see if it also would stay “in nice shape.” Cold-blooded experimenters have no business in the rifle game; they take all the romance out of it, dog-gone ’em.
In these days metal fouling troubles but little, and intensive experiments are under way with the foreign artillery discovery of tin, lead and zinc, to find the best way to apply it to exorcise this old trouble of the rifleman's. The last excuse for cup grease is nearly gone, except possibly when cartridge companies load nitroglycerine powders behind 180-grain bullets.
It is true that experiments by the Marines in 1913 seemed to prove that the use of grease without cleaning at all during the summer's shoots gave more consistent accuracy and slightly longer life, but they had two experiments wrapped up into one, and the average rifleman is not going to let his pet go uncleaned over night as did the Marines.
The little joker as to why they could let their rifles go uncleaned as they did is explained in two ways. The first is the nature of what we have loosely referred to as grease, Diving into a book on motor cars the other day to find what grease was, I was much surprised to find that it was nothing but soap thoroughly impregnated with a mineral oil. This, it is stated, is the general makeup of what is known as cup grease, and which classification takes in mobile lubricant and Acme cup and others used by riflemen.
Now, if you take soap, impregnate it with mineral oil and one other ingredient, you have B. S. A. Saftetipaste, the most successful barrel preservative on the market. Wherefore the Marines’ freedom from the demon rust in their rifles.
The other reason is that they didn’t give two whoops, because rarely does a Marine ever use the same barrel two consecutive shooting seasons.
In spite of all this, and that I have never had a gent look me in the eye and tell me that he knew positively of a case where two rifles of the same lot of barrel steel, and the same star gauging, were shot until one of them wore out; one of them used with grease, the other without. This is the only proof of the pudding, and such proof has never been made. All we ever get is conflicting personal opinions under different conditions and with estimated amounts fired through the rifles, which is proof as positive as that advanced by Pappy Lodge as to the materialization of spirits.
When an officer of the Small Arms Ballistic Station in Florida, which was established to conduct experiments with machine guns and machine rest for ballistic purposes, I suggested to Colonel Wilhelm that Frank ford be requested to load about 12,000 rounds of ammunition having a narrow band of wax and graphite where the bullet joined the case, and another lot with the entire bullet coated with this composition. This is the old Ross formula for match ammunition.
The lots were alike, in being loaded with the model of 1909 boat-tail bullet and a certain lot of powder not on the market, but with which we were familiar as to erosion results.
Both lots were fired in March of 1920. The lot with the narrow band, simulating in amount the grease put on by the careful rifleman, wore out the barrel in 7,900 rounds of firing through the machine gun.
The lot completely coated over went 9,700, but neither showed any particular addition to the barrel life noted with the dry bullets and the same powder and 2,600 f. s. velocity. The difference in the two lots was that noted in many rests with precisely the same ammunition.
What wears out a machine gun or rifle barrel is of course apparent to anyone who has followed the subject of small arms—merely powder gas erosion. The proportion of bullet wear to powder gas washing is so low that the reduction of the bullet wear to nothing probably would not length en the barrel life 10 per cent. The lesson was plain in observing the effect of two different kinds of powder.
One sort wore out the barrel by putting scooped-out places in the bore just forward of the lead and roughening up the bore and washing off the lands, but all within the first eight inches of barrel.
The other sort, coated and slow burning, did not injure the bore noticeably at any one spot, but washed away the lands the entire barrel length. It was plain to the eye and checked up with the star gauge and plugs.
There must be, of course, a slight wear of the lands at the bullet entrance, because they act as a die to size the bullet to form and shape, but this is restricted to the first inch, and the effect is so quickly covered up by the harsher effect of the powder gas that no rifleman ever saw it by itself. Wherefore it is obvious that grease can do nothing for a barrel but slightly reduce bullet friction and thus help to keep down metal fouling.
All this is considering the beneficial effect of grease. A phase of it I have not touched on is one of the ways that are dark but useful, nevertheless, in rapid fire. This is merely to rub a grease-coated finger over the bodies of the cartridges of the first clip to go into the rifle. Without question, it runs up the bolt-head thrust, and likewise, without question, it makes the cases extract easier and permits that smooth mechanical throw of the bolt that makes for ten waves of the white paddle.
The chronograph and thousand-yard shooting from the Mann rest both prove that grease does not raise the velocity of the bullet as it leaves the bore, and therefore its reduction of friction is not one that is susceptible of measurement. I tested greased and ungreased ammunition repeatedly at Daytona at 1.000 yards from the Mann rest and never found the slightest difference in point of impact. If you fire ten without grease and then with grease at 1,000 yards, they will intermingle until you cannot tell one from the other.
This was with the bullet carefully and sparingly greased and the chamber kept dry.
When grease does raise the velocity is when it raises the pressure, but this does not prove that its heightened velocity is a result of lessened friction; it is merely equivalent to a heavier load.
Two years ago I was sent on a trip through the arms plants and arsenals from Camp Benning on orders which had been asked for from Camp Perry before the armistice. For this trip I have my good friend Colonel Mumma to thank. Its purpose was to become familiar with manufacturing processes and to study the experimental methods of the various plants visited. The trip, being made on orders that were rather of the blanket variety, permitted visiting for a short time some plants not on the orders, and full advantage was taken of the chance. In the two months practically every arms plant, Government and private, and every ammunition factory on the Atlantic seaboard was visited.
One of the things which had long aroused my curiosity was the performance of grease under the cold eye of the pressure gun and the chronograph.
Wherefore, arriving at Springfield and being made welcome to the experimental department by my friend Major Fiala, one of the things I asked for was a show-down of the grease question.
We had no straight mobile lubricant, so used a mixture of sperm oil and cosmic, which gave a nice slippery mixture. The first verse was with the bullet and neck greased as they are when poked into a can of grease as the average rifleman does the trick. Two shots of the ammunition
we were to use, fired dry, gave a mean of 47,000 pounds velocity; instrumental. 2,655, equal to 2,695 muzzle.
Neck and bullet greased gave a minimum pressure of 51,100; maximum, 60,600; velocity, minimum, 2,757; maximum, 2.804.
Case and bullet given thin, even coat: High pressure, 52,100; low, 47,100; high velocity, 2.800; low, 2,700. This velocity was inconsistent with the pressures, but both were lower than with gobs of grease on the case neck.
Bullet greased carefully, none on case: High pressure, 54,600; low. 49,100: high velocity, 2.777; low, 2,744.
So we called it a day and passed on to chronographing the model 1917 rifle about which I had been curious.
When I got over to Frankford I got my old friend George Schnerring to repeat the grease test, using mobile lubricant. Frankford being an ammunition factory, making the crushers for test at other arsenals and establishing the standard, ought to be entirely reliable as to the ballistic results obtained.
So the gun roared and the weight fell into the dash pot full of beans, and the crusher got pushed into itself. Four shots of standard ammunition, Frankford service of 1919 loading, gave the following—fired dry, of course: Pressure. 47,700, 50,700, 48,600. 49,400 x velocity 2,610, 2,637, 2,616, 2.625, instrumental, to which add 60 f. s. for muzzle, as they take their velocities over a 150-foot range. In other words, the high pressure was 50,700; low, 47,700; difference, 5,000 pounds. Difference in velocity, 27 feet, with 2,637 the high figure. Now let's see how the story ran after the dark villain came into the plot.
Five shots, bullets greased by twirling them up to the neck of the case in the lubricant
51,200 _____________ __ 2,667
63,100 _____________ __ 2,804
56,750 _____________ __ 2,753
65,470 _____________ __ 2,849
54,550 _____________ __ 2,740
Five shots, bullet and case greased:
50,350 _____________ __ 2,706
44,900 _____________ __ 2,656
49,700 _____________ __ 2,657
48,400 _____________ __ 2,670
55,160 _____________ __ 2,753
As the Springfield test showed, pressures were increased more by grease in plenty around the neck of the case than by a thin, even coating on the entire case. As I applied the grease myself, I know just how it was done.
So, as the cold figures show, taken by expert chronograph and pressure gun men, grease applied by the common or garden variety of poking bullet and neck of case into the can, gave a high pressure of 65,470 pounds and a high velocity of 2,849, equal to 2,909 muzzle. The pressure varied 14,000 pounds and the velocity 182 f. s. Isn't that a pretty dish to set before the king?
With a thin coat over the bullet and case, simulating the usual nice oiled chamber after a few shots on a hot day, high pressure was 55,160; low, 44,9900; variation, 10,260; high velocity, 2,753; low, 2,656; difference, 97 f. s. A peculiarity of this test was the one low pressure with velocity still up to normal.
If the case is left dry, the pressure registered this way is comparatively little, giving an effective example of the way bolt head thrust is increased by the greasy chamber that invariably follows the ordinary rifleman's method of using the lubricant
Eight years ago in “Outer's Book" of Milwaukee I pointed out this little joker in the use of grease, and the likely connection with had with the flock of cracked bolt lugs at Perry in 1913. It develops the maximum possible bolt-head thrust, because the wall of the case does not cling to the chamber walls, and the case sits down hard on the bolt. It is a close parallel to the unfortunate accident told of by the poet:
“There was a young lady named Anna,
Who stepped on a ripe old banana,
She lit on the street,
But not on her feet,
And now she can't play the piana."
The whole trouble in this happening was that the banana eliminated the friction between the young lady's foot and the pavement, just as grease in the chamber eliminates it between chamber and case.
The Du Pont figures being more assuring to the Grecians than those of the arsenals, I decided, if possible, to get the Frankford Arsenal to settle the matter by official test, and to that end suggested to the C. O. of the Infantry School of Arms at Camp Benning to write, asking for a full and detailed test of the grease business. I asked that figures be obtained, first, for the dry cartridges to show the variation to be expected in velocity and pressure; second, for the cartridges twirled to the necks in a can of grease a la the favored way of applying it by the hoi poloi, and, third, for the cartridges with a thin coat of grease on the bullet.