View Full Version : .22 LR power vs bolt weight and springs
How much rearward force (recoil) does a .22lr produce upon firing? What size (poundage) recoil springs are used on semiautos in this caliber (rifles and pistols)? If someone happens to know the weights of the bolt assy/slide on Ruger 10-22 and mark one style pistols that'd probably help as well.
Anything else I may not have mentioned that you might think helpful and applicable, throw that in there too...
Maybe we can have this moved?
There are few firearms enthusiasts who do not already know how the Ruger story began with the appearance of a small advertisement in the pages of the American Rifleman in the summer of 1949, heralding “The .22 RUGER pistol... the first overall improvement in automatic pistol design since the Browning patent of 1905.” Bold words, but the efficient, reliable, accurate, and inexpensive ($37.50 introductory price) Ruger Standard Model soon became, and remains today, the largest selling, most popular .22 autoloading pistol in history. The first version featured a 4 3/4-inch tapered barrel with six-groove, 1:14-inch RH twist rifling. It was definitely different from all .22 auto pistols that had come before.
It had no “slide” as in conventional-form autoloaders but instead employed a cylindrical bolt that operated within a tubular receiver, more resembling a .22 autoloading rifle than other .22 semiautomatic pistols. Coil/music-wire springs, not conventional flat springs, were used throughout its mechanism. The dovetailed rear sight was fixed atop the receiver and therefore did not move when the gun was fired. From a manufacturing point of view, perhaps its most innovative aspect was that the frame was constructed of facing halves stamped from two flat sheets of steel then welded together. Again, not typical, but plenty strong for a .22 rimfire action and less expensive to produce than the forged or milled frames of other .22 pistol models—the main reason for the Ruger pistol’s remarkably low price against its competition, a position it has maintained for many years.
The Ruger .22 pistol was an instant success. The first production shipped in autumn 1949, and from that moment forward Sturm, Ruger & Co. has been sustained by profit from sales. As soon as the Standard Model went to market, new versions, variations, and small design modifications and refinements began to be produced. The first major addition was the Mark I Target Automatic, which wasannounced in December 1950. Mechanically the same as the Standard Model, it had a tapered 6 7/8-inch barrel, a Patridge front sight blade undercut to reduce glare, a “Micro-adjustable” rear sight, and an improved trigger with stops to reduce slack and overtravel. More variations and configurations followed, and all versions sold very well. The one-millionth Ruger Standard Model pistol came off the line in 1979.
Throughout the first 33 years of continuous production,the basic mechanical operation of all versions of the Standard Model and Mark I pistols remained essentially unchanged, with differences only in barrel shape and length and type of sights. The final original-design pistol came off the assembly line on the last working day of December 1981 and was immediately replaced by the Mark II Standard Model and Mark II Target Model series, which had the same list of variations in terms of barrel styles and sight systems but also included several new mechanical features. For one, there was a long-anticipated bolt lock plus a pair of recesses at the rear sides of the receiver for easier grasp of the bolt when cocking. A magazine redesign gave 10-round capacity instead of the previous nine. Most significantly, the safety was redesigned so that it locked only the sear (instead of bolt and sear together), which allowed the bolt to be pulled to the rear for visual inspection of the chamber while the safety was engaged instead of requiring the safety to be taken off to inspect the chamber. The trigger pivot retainer was redesigned with a music-wire spring instead of a lock= washer to make it easier to disassemble and reassemble the gun.
The new Mark II pistols continued to be as popular as their predecessors, with many more new versions added in the nearly 20 years since the transition. The 2000 Ruger catalog lists 17 individual current model variations of the gun, ranging in price from $265 to $486, including blue-steel, stainless-steel, and polymer-frame versions; barrel lengths from four to 10 inches, tapered or bull barrels; fixed or adjustable sights. Ruger offers the largest number of sporting .22 rimfire pistols in the world—there’s something for everybody. Half a century on the block and demand has never slowed.
Automatic and Semi-Automatic operating principles
A semiautomatic weapon unlocks, extracts, ejects, cocks, and reloads automatically. However, the trigger must be pulled each time to fire a round. A fully automatic weapon keeps on firing as long as the trigger is kept pulled. Some weapons can be fired both automatically and semi-automatically, e.g. the 7.62-mm M14 rifle and the 5.56-mm M16 rifle.
Automatic and semiautomatic weapons are classified on the basis of how they obtain the energy required for operation. Fundamentally, small arms obtain the energy from the forces that accompany the explosion created when around of ammunition is fired. The use of these forces does not reduce the effectiveness of the weapon but uses otherwise wasted energy.
There are three basic types of operation for semiautomatic and automatic small arms-gas operation, recoil operation, and blowback operation.
In gas-operated weapons, a portion of the expanding powder gases behind the bullet is tapped off into a gas cylinder located beneath the barrel. (The hole connecting the barrel and cylinder is near the muzzle end.) As the bullet passes this hole, gases push this piston rearward. The piston is connected by a rod to an operating mechanism of the weapon, such as the bolt. The piston carries the bolt forward with it, unlocking, extracting, ejecting, and cocking the weapon.
Three basic types of gas systems are used in semiautomatic and automatic small arms. They are the gas impingement, gas tappet, and gas expansion systems.
Gas Impingement System: The impingement system has a negligible volume of gas at the cylinder with expansion dependent on piston motion. As the piston moves, gas continues pouring through the port until the bullet exits the muzzle with a subsequent drop in pressure in the bore. An example of such a mechanism is found in the Ml Garand rifle, which was the standard service rifle in World War II and the Korean war.
Gas Tappet System: The gas tappet system is an impingement system with a short piston travel. It is often referred to as a gas short stroke system. An example of such a mechanism is found in the Ml and M1A1 .30-cal. carbine. In some tappet mechanisms, the piston only taps the lock mechanism open and exerts no force to recoiling components.
Gas Expansion System: The gas expansion system, in contrast to the impingement system, has an appreciable initial volume of gas in its expansion chamber. This requires more time to pressurize the chamber and also more time to exhaust the gas by selection of port size and location as the required pressurized gas can be drained from the bore. There is also a cut-off expansion that is similar to the direct expansion system, except for a valve that closes the port after the piston moves. As the pressure builds up to a specific value, the piston moves, closing the port and leaving the gas to expand, providing the force effort needed to operate the moving components. The 7.62-mm M14 rifle uses this type of operation.
As a round is fired, high pressures develop behind the bullet and force it down the barrel. The force behind the bullet is also directed rearward against the breech. If the barrel and bolt are secured to one another, the entire force of recoil is felt on the shooter's shoulder. But, by designing the barrel and breech assembly so that they can slide in the frame or receiver, the energy of the rear moving assembly can be used to compress springs, move levers etc. as necessary to complete the cycle of operation.
Generally, in recoil-operated weapons, the barrel and the bolt move rearward together for a short distance. Then the barrel is stopped and the bolt (now unlocked) continues to the rear against spring pressure until the empty case is ejected. The force of recoil is also used to cock the weapon and compress the spring, returning the bolt to its firing position and cambering a new round in the process.
There are two basic methods of recoil operation for semiautomatic and automatic small arms. They are the long-recoil (Browning) and short-recoil (Maxim) methods.
Long-Recoil Method: The dynamics of long-recoil-operated weapons are similar to straight blowback operation, except that the barrel, breechblock, and component parts recoil together for the complete recoil cycle. This recoil distance must be greater than the length of the complete round. At the end of the recoil stroke, the bolt is held while the barrel counter recoils alone. One particular note of importance on the long-recoil type of operation is that ejection takes place on counter recoil instead of recoil. An example of a long-recoil weapon is the Browning designed, Remington Model 11 Shotgun, used by the US Armed Forces before and during World War II.
Short-Recoil Method: The dynamics of short-recoil-operated weapons approach those of the retarded blowback types more nearly than long-recoil. The bolt latch is not released until the propellant gases become ineffective to eliminate all blowback tendencies. After unlatching (unlocking), the bolt continues recoiling and in some mechanisms is accelerated by mechanical or gas systems. The barrel is arrested by spring, buffer, stop, or a combination of these and is caused to return to the locked position by these or the counter recoiling components. Examples of short-recoil-operated weapons are the .45-cal. pistol and the Browning machine gun.
There are some similarities between recoil and blowback-operated weapons. But there are several major differences. In recoil operation, the bolt and barrel are locked together until the bullet has left the barrel and most of the recoil thrust is spent. The combined thrust of the recoiling barrel, bolt, and some other parts is used to operate the weapon. In blowback (inertia) operation, however, the bolt is not locked to the barrel and, in most cases, the barrel does not recoil. The bolt is held closed by spring pressure and the mass of the breechblock. The initial blow of the exploding cartridge starts the bolt moving rearward, but the weight of the bolt is such that it does not allow the chamber to be entirely opened until the round has left the bore. Action by a recoil spring returns the bolt to the closed position, chambering a new round.
Thus the weight of the breech bolt is an important factor in the design and operation of a blowback-operated weapon. When used with low-powered ammunition, it is a suitable arrangement. A military rifle, however, using the standard .30-cal. cartridge and the blowback action, would require a 27-pound breechblock.
Besides the submachine gun, many types of so-called pocket automatic pistols and .22-cal. automatic rifles use blowback operations.
There are variants in the methods used for each of these types to operate the mechanism for blowback. These are the straight blowback, retarded blowback, and accelerated blowback methods.
Straight Blowback Method: Straight blowback is the most elementary and simple. It uses recoil energy from the firing of a round of ammunition to operate the mechanism of the weapon and extract the fired case, eject it against spring tension, and return the mechanism to firing position again. This, in turn, picks up an unfired round from a magazine and chambers it. Straight blowback is used in weapons that fire ammunition of fairly low power, such as pistol ammunition and .22-cal. rimfire rifle cartridges. The bolt slide or breechblock is fairly heavy in these weapons when compared to the weight of the bullet and power of the cartridge. Therefore, the mechanism will stay closed (but not locked) momentarily until the bullet gets free of the barrel and pressure is subdued to allow extraction. All submachine guns and semiautomatic .22-cal. rimfire pistols use straight blowback for their operation.
Retarded Blowback Method: An example of retarded blowback is found in the mechanism of the original Thompson submachine gun. This is based on the principle of operation that the recoil force exerted on the mechanism must overcome some form of mechanical disadvantage, momentarily holding the breechblock closed until the bullet had cleared the muzzle of the weapon. However, this was later found unnecessary if the bolt or breechblock was of sufficient weight.
Accelerated Blowback Method: An example of accelerated blowback is found in the .22-cal. rimfire Colt Ace semiautomatic pistol. In this pistol, the Williams floating chamber, a part of the barrel on firing a round of ammunition, moves with accelerated force against the mechanism (in this case, the fairly heavy slide and its components), providing sufficient energy to operate the component parts of a .45-cal. pistol with .22-cal. rimfire ammunition.
M-16 22LR conversion
Mini 14 22LR conversion
Conversion Kit, 22, Govt., Adjustable Sight. Fits: A, E, F, H & O. Pkg. Includes: Top End Unit, Main Spring (#21), One .22 Magazine.
It looks like the 1911 22LR conversion uses a 21 pound spring.Not sure of the slide weight.
Oh that's MAIN spring (hammer spring) not the recoil spring.
Glock 22 LR conversion
Caliber - .22LR
Capacity - 10-rd. box magazine
Action - Host Glock pistol
Barrel - 4.3 inches
Weight - 6.5 oz. (conversion upper only)
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