the barrel. The bolt remains in this position from the time the gun is fully cocked until it is fired, and is not depressed or unlocked from the cylinder until the arm is cocked for firing again.
The common belief is that each time a revolver is cocked the uppermost chamber is in perfect alignment with the axis of the bore of the barrel but, unfortunately, this is not exactly true. In Colt revolvers the cylinders revolve to the right. The hand is located as far as passible to the left of the center of the frame and the bolt as far as is convenient to the right of the bottom of the frame. These guns are so adjusted tliat when the trigger is at its rearmost position, or at the position at which it is when the sear is released and the arm is fired, the hand is exert ing pressure on the cylinder, rotating it against the resistance of the bolt. In other words, with the trigger all the way back, the cylinder is loeked.
The method of checking the alignment of the chambers with the barrel, when the cylinder is in position for firing, is to pass a plug gauge that fits the bore closely through the barrel and into each chamber. If the plug passes freely into the chambers, the alignment is considered correct. It should be borne in mind, however, that this plug is of bore and not groove diameter. Therefore, a chamber might be out of alignment by as much as the depth of one groove and the plug would still enter freely. Furthermore, the throats in the cylinders, or that portion just ahead of each chamber which acts as a guide to the bullet before it enters the barrel, are invariably of larger diameter than the groove diameter of the barrel. It will, therefore, be seen that it is possible for a chamber to be several thousandths of an inch out of alignment and still pass the factory test.
In Smith & Wesson revolvers the mechanism is so adjusted that when the cylinder is in the firing position there is a slight amount of play in it. This play is ap-parendy purposely left to give the cylinder itself a chance to compensate for any small variations in alignment when the bullet is passing from the cylinder into the barrel. Whether there is time for any such compensation is questionable, but certainly the principle is not harmful even if the practical effect is not apparent.
I realize that many revolver shooters will be horrified to learn that their cylinders do not necessarily line up precisely with the barrels of their revolver, but the litdc variations which do exist should not be considered so much in the light of defects as merely limitations that are necessary in the particular type of arm.
Anyone can very easily examine his own gun for alignment if he wishes to verify these statements. All that is necessary is to cock the gun, holding its trigger and the hammer back. At the same time, point the gun towards a strong light or insert a small flash lighr in the muzzle, then look through the hole in the recoil plate from the rear. By looking past the hammer on either side, it is possible to see both sides of the bore through the chamber. If there is any play in the cylinder it can be worked back and forth so that its relation to the barrel may be seen. If you do this little stunt, don't throw a "cat fit" over what you see, or complain to the manufacturer that your gun is no good. The revolver is an intricate piece oE mechanism and it is remarkable that the manufacturers arc able to get the cylinder alignment as good as they do, without making the cost of the guns prohibitive.
The revolver is essentially a short range weapon.- Fired with one hand, unsupported and with such a short sight radius, no one expects to get 1" or 2" groups at 100 yards, nnr rniild they, f-vrept by lurk, nn matfrr how accurately a revolver might be made. The longest range at which one is ordinarily used is about 50 yards and all revolver targets have bullscycs and counting rings very much larger than rifle targets used at similar distances. Yet in 301 spite of the limitations in the design of revolvers, and the minor tolerances in their working parts, they will shoot with excellent accuracy provided the capabilities of the shooter are equal to those of the gun.
However, to further assuage the feelings of those individuals who may have believed that the chamber and barrel alignment of revolvers is the very csscncc of perfection it may be stated here, leaving the details until further along, that even though cylinder alignment IS perfect, it is a matter of chance whether or not a revolver bullet passes from the cylinder into the barrel with its axis in perfect alignment and coincident with the axis of the bore.
As the chambers of a revolver are entirely separate from the barrel, it is impossible for the bullets to be in closc contact with the rifling before they are fired. The bullets must jump forward at a considerable velocity and more or less without support before they strike the rifling. They also must be seated deeply enough in the cases so they will not project beyond the front ends of the chambers, as this would prevent the cylinders from rotating.
The throats of the chambers are always larger in diameter than the groove diameter of the barrel and normally, revolver bullets do not upset or expand much when they are fired. The degree of upscttagc, if any, depends upon the hardness of the bullets and the nature of the powder charge used behind them, but as a general rule solid base bullets do not expand sufficiendy to fill the throat3 con-sequendy die bullet must pass from the chamber into the barrel more or less unsupported. The accuracy of the arm depends largely upon how well the bullet is guided between the time it leaves the case and enters the barrel. If an attempt were made to load bullets that were as large in diameter as the throats of the chambers, the resultant cartridge would in most instances be so large at the neck that the ammunition would not enter the chamber. Furthermore, this diameter might be so much greater than the 301 groove diameter of the barrel that dangerous pressures might develop from attempting to force such an oversize bullet into the barrel.
The considerable jump that a revolver bullet must make before it comcs in contact with the rifling permits it to attain a rather high velocity, consequendy its contact with the lands and grooves is accompanied by a considerable shock. Due to this velocity that it attains while moving forward through the throat of the chamber and the barrel cone, it has a tendency to drive straight forward into the barrel, ignoring the rifling. Normally, the resistance offered by the inclined driving edges of the lands cause this forward movement to be overcome quickly, and under conditions of proper loading the bullet usually attains its normal rate of rotation before it has entered the rifling for its entire length. These "slippage" marks can be seen on almost any of the bullets illustrated in this chapter of the text. The amount of slippage depends upon the hardness of the bullet, its velocity, the nature of the rifling and the relation between the bullet and bore diameters.
If a soft, short revolver bullet is fired at too high a velocity these slippage marks will extend all the way back to the base of the bullet. If in addition the barrel is a short one, the bullet may never attain its proper rate of rotation. It is doubtful if this is true in a barrel of normal length, say from 4" up, for after all a bullet depends for its rotation only upon one edge of cach land of the rifling and even though a short bullet docs show slippage dear to its base, it may still acquire a normal degree of rotation because of the resistance offered by the driving edge of the lands. In actual practice, however, bullets which show an abnormal degree of slippage do not perform well and it is advisable not to use short bullets for so called high velocity loads. When using such loads the bullet alloy should be stiffened or hardened. This hardening of the bullets when 303 used with the heavier loads has a three-fold beneficial effect. The slippage is reduced. There is less tendency for the bullet base to upset excessively when passing from the cylinder into the barrel. There will be less tendency for the barrel to lead than if a softer bullet were used. All of these things contribute to good accuracy.
As a matter of fact, the normal jump of a rifle bullet may also be sufficient to cause some slippage, but as rifle
Results of slippage, tipping and* shaving of bullets.
A—Fired bullet showing perfect rifling marks, no Indications of tipping, sUppage or shaving. B—Bullet showing slippage. Note that left hand edge of rifling mark on bullet is straight, showing that bullet plowed straight forward into rifling for some distance before taking ap rotation. C—Bullet showing two sets of rifling marks with different angles, Indicating that bullet was badly tipped when it entered buUet seat, but later straightened up. D—Bullet badly shaved on left side as a result of poor alignment of revolver cylinder.
bullets normally jump a much shorter distance than is the case in revolvers and because of the use of slower burning powders, they probably do not acquire as high a velocity over the short, distance of jump as a revolver bullet. Therefore, the effect of slippage m a rifle is negligible, especially with jacketed bullets, and can practically be eliminated by seating the bullets out of the cases far enough so that they will be in contact with the rifling before the cartridge is fired.
In revolvers, the general rule is to use moderate loads with short or soft bullets and longer and harder bullets for the heavier loads.
Very rarely a revolver barrel will split at the rear end but this can be caused by the excessive upsetting of a soft 304 bullet just as well as it can by a jacketed bullet and is not likely to happen at all with a cast bullet made from a fairly hard alloy.
In rifles the groove diameter of the barrel may be used as a guide for the proper sizing of cast bullets, but with the revolver, consideration must also be given to the throat;
as a conscquence, it is common to iind that revolver bullets are smaller than the throats of their chambers and sometimes several thousandths of an inch larger than the groove diameter of the barrel. It is disadvantageous to use bullets that are much above the standard size of revolver bullets loaded by the commercial ammunition manufacturers. These bullet diameters have been arrived at as the result of long experience in many different arms and while some departure from these standards is permissible in some individual weapons, it cannot be recommended in general.
Now let us take a look at what happens if an over-size bullet is used. When a cartridge is fired, the cartridge case expands before the bullet has time to overcome its Inertia and move forward, because less pressure and time arc required to expand the thin case than to move the comparatively heavy bullet. In other words, the case lets go of the bullet first. The crimp, especially if it is a heavy one, may retard the forward movement of the bullet, but probably most of this crimp is forced out by the gas pressure, even though the crimp later springs back part way. As the bullet is at best smaller than the throat or guiding portion of the chamber it is a matter of chance as to the direction and amount of tip that the bullet takes before it enters the barrel. With bullets of standard diameter in modern guns there is not a great deal of tipping, if there was we would not get the accuracy we do; but, even so, the bullets do usually strike on one side of the rifling harder than the other. That this is true can be readily determined by marking the bullets to indicate their positions when fired and examining them after they are recovered. This condition may be aggravated by a slight misalignment of the chamber and barrel, but it occurs with ammunition fired from chambers that are in perfect alignment with the barrel. On the other hand, there arc indications that at times a small error in alignment may actually compensate for any slight tipping of the bullet Now if bullets arc sized down to the groove diameter of the barrel, the clearance between the bullet and the guiding walls of the throat of the cylinder, upon which it depends for its alignment, will be increased and the angular entrance of the bullet into the barrel may also be increased.
In determining the proper diameter for revolver bullets, this haphazard movement of the bullet before it comes in contact with the rifling, the relatively large diameter of the throat, and relatively small diameter across the grooves, leaves one between the devil and the deep blue sea, except for the one saving grace that even experienced reloaders sometimes overlook. This saving grace is the standard diameter of revolver bullets—that has been determined upon after years of experience and experimentation. I repeat that this does not mean that the diameters of cast bullets for revolvers should not or can not be varied from the factory standard to meet litdc peculiarities in individual guns, but it does mean that unless the reloader has had considerable experience with reloading, he will probably get the best results if he sticks to the standard factory diameters.
The question may arise as to how much difference a few thousandths of an inch one way or the other from the standard-bullet diameter will make in the accuracy of the ammunition. There is no fixed rule. The difference will usually only be slight and probably not enough to be noticeable to the average pistol shooter—but there is a difference. Comments of this kind are apt to create the impression that a bullet of normal diameter will shoot well, while one of slighdy smaller diameter will shoot all over the lot. This is not necessarily the case, but it is true that the
306 difference will be more noticeable with short light weight bullets than with the longer bullets of standard weight. The shorter bullets have more opportunity to tip and their angle of tip will be greater than that of a bullet of normal bearing length. One of the advantages of sharp shoulder bullets lies in their longer bearing length and the lesser opportunity there is for them to tip while passing through the throat, but such advantage as this may give them is more than offset by their miserable ballistic shape.
There is another factor to be considered; namely, leading. I have mentioned the subject of leading in a number of places in this book and have quickly steered off from it onto something else. The reason is that I know very litde about it. I have been fooling around with the subject and experimenting with it for about 14 years and with all types of weapons and I can't give a definite solution to this problem for any particular type of gun. What works in one gun doesn't seem to work in another, but there is one thing that can be stated quite definitely and that is that the relation of bullet diameter to throat diameter in a revolver has some bearing upon leading. If the clearance 3°5 between the bullet and the throat arc sufficient (and they usually are) gas rushes past the bullet, blowing particles of lead from the edges of the base and the bands; if these particles of lead adhere to the barrel, leading will build up. The bullet diameter is not the whole story and the actual clearance between it and the throat involves the bullet hardness and the powder charge used behind it, and the bullet hardness involves the alloy which also has something to do with the question.
If the reader is inclined to doubt that lead is blown off from the bullet before it enters the barrel, he should examine the outside of the cylinder of his revolver the next time he gets through shooting it Over the top of each chamber at a distance of about back from the front end of the cylinder there will probably be a distinct and
307 heavy smudge. It may only be a mixture of bullet lubricant and powder fouling, but it usually requires a litde rubbing to remove it and oftentimes shows a distinct lead color. The lead is easily rubbed off, but it had to come out between the barrel and the cylinder before the bullet passed into the barrel. The heavier the loads the more pronounced this condition will be.
Before sneaking out from under this subject of leading once more, I would like to say that the condition which frcquendy occurs in revolvers where a deposit u£ lead is left around the rear end of the barrel but does not increase appreciably with continued firing, I do not consider leading, nor do I believe any particular attention should be paid to it other than from an experimental standpoint.
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