bigpete wrote:If all that worked as you say,then wouldn't there be rifles fitted with squeeze bore barrels with stuffed actions or blown cases ? Arthur Langford squeezed them down to .17 with apparently no ill effects even with high velocity 22 ammo. As for if it would stabilise....probably not but you never know unless you try.
I've never seen one of Langford's rifles. Were they standard .22LR actions? Could you use the highest velocity .22LR ammo in them? What barrel lengths did he use? Any idea what twist rate he used? I'd love to see a recovered bullet. The 40gn bullet would come out the muzzle about .690" long - almost 50% longer than it started.
Easy enough to make your own, especially with the CZ455, just put a .22LR reamer into the .172" barrel, and taper the throat to suit.
Actually, I found an article. 1248fp ammo made 1337fps in .204" and 1445fps in .172". That might have been worth messing with back then, but now we have standard .22LR ammo making 1435fps, and it shoots very well in most rifles I've tried it in.
https://www.thefreelibrary.com/Langsford%27s+squeeze-bore+rimfires%3A+is+this+near-forgotten+idea+too...-a0268869254"Taper-bores are the stuff dreams are made of. Imagine firing a bullet that begins life as one caliber down a bore that progressively gets smaller and smaller in diameter. What emerges is a bullet of smaller caliber with an improved ballistic coefficient at a relatively high velocity. The late Australian gunsmith and cartridge designer, Arthur Langsford, had a better idea. Why not just dispense with the taper-bore design and simply fire a conventional .22 Long Rifle cartridge down a 17- or 20-caliber barrel and see what you get? What he got is one of the most intriguing stories in rimfire history.
Langsford's earliest rimfire experiments centered around the development of sub-caliber wildcats using unloaded ICI .22 LR shot cases, no less, necking them down to. 17 as his "Minor-Mite" and "Vixen" cartridges as well as his "Tini-Mite" series in .08, .11, .14 and. 17 calibers. The. 17 TiniMite was actually produced and sold in some quantity through his Myra's Sports Store in Broken Hill, Australia. None was quite the commercial success he had hoped for, but Langsford was 20 years or so ahead of the commercial appearance of the 5mm Remington Rimfire Magnum, .17 HMR and .17 on to pursue a better idea.
He reckoned if using a soft lead bullet he might be able to squeeze it down in caliber and still achieve reasonable accuracy as well as higher velocity and an improved bullet form. Jacketed bullets had always proved a problem in taper-bore guns. Some of the better known experiments included the German Gerlich gun using a flanged bullet that gradually collapsed as it progressed down a tapered-bore barrel.
While taper-bore barrels proved expensive and a pain to make and were subsequently abandoned, during bore, anti-tank cannons like the 42mm PAK 41 that fired a 42mm Gerlichtype projectile that left the muzzle as a 30mm shell after having been squeezed down in a smaller diameter, smoothbore portion of the barrel.
In the US, there was also some early work in 1942-43 at the Frankfort Arsenal Laboratory, which focused on the .50 BMG cartridge loaded with sub-caliber 30- and 35-caliber bullets encased in either ventilated, collapsing jackets or disintegrating sabots. While the experiments were terminated in 1943 for more pressing war time priorities, the sabot design did reemerge later as the current .50 BMG Saboted Light Armor Penetrator "SLAP" round.
Extruders
But back to Mr. Langsford and his "Extruders." That's what he called his new cartridge series--the Extruders--actually the "Myra Extruders--"Myra being his wife. Langsford's solution to the squeeze-bore challenge called for the use of a standard diameter 17- caliber or 20-caliber barrel with 1:6.5" to 1:8" twist. While the barrel was chambered for the conventional .22 Long Rifle cartridge, the secret lay in the form of the throat or lead. Langsford designed a forcing cone in the throat that eased the bullet into the smaller bore without damaging it. The picture (sorry, but these were Langsford's original photographs) illustrating the gradual transformation of a .22 bullet into. 17 projectile clearly shows the angle and structure of the forcing cone. He called his squeeze-bore design the "Myra Extruder" and indeed that's just what the process did, it extruded a bullet into a completely new form. Because the extruding process elongated the bullet, the faster twist barrels he used were essential.
In fact, he got a bit carried away with the idea that a faster twist imbued the bullet with greater hydraulic shock, penetration and lethality. It was good marketing, although he seemed to be right about penetration if the photo he sent me showing the comparative impacts of a conventional .22 LR Mini-Mag, .20 and .17 "extruded" Mini-Mags on a 6" steel post is accurate. The .22 LR just splashes against the post while the "Extruders" penetrate fully. Unbiased, third-party tests later did confirm Langsford's claim for improved penetration with the Extruders.
The chronograph and ballistic data Lansford furnished me is interesting. The test gun was a Model 2 Brno fitted with a standard factory barrel and subsequently with .20 and .17 Extruder barrels. The test cartridge was Winchester's Super-X PowerPoint with its 40-grain HP clocking 1,248 fps at the muzzle from the Brno barrel. When "extruded" from the 20-caliber barrel, the muzzle velocity was 1,337 fps and from the 17-caliber barrel, 1,445 fps. Retained energy at 100 yards for the three bullets was 84, 99 and 124 ft-lbs respectfully. Drop at 100 yards, 13.6", 11.6" and 9.6" and with a 10 mph crosswind; deflections at 100 yards for the three bullets were 6.3", 5.4" and 4". Langsford claimed, when compared to the standard Power-Point, the .17 Extruder from the muzzle to 150 yards averaged 20 percent more velocity, 47 percent more energy and 47 percent less wind deflection.
The first question many raised to his Extruders was what about pressure? Squeezing a .22 caliber bullet down to .20 or .17 had to raise pressures. Langsford addressed concerns about excessive pressures in two different ways.
First, he took standard .22 LRHV cartridges and, through a small hole in the case walls, drained out all the powder. He then began trickling powder back into the case and firing the rounds until the bullets were completely extruded through the chamber throat and seated fully in the breech of the 20-caliber barrel. He found it took only 2.5 percent of the original charge to complete the short extrusion. The second was an ad he ran in the April, 1994 issue of the Australian Shooters Journal illustrating a simple, but rather unconventional, pressure gun fixture he invented and presumably was using as a control instrument. The ad copy he sent me had his handwritten note on it, reading "Our latest pressure deflating ad! Regards, Arthur."
Third party testers, experienced no pressure signs when working with the .20 Extruder, but Langsford admitted the .17 Extruder was not consistent when it came to pressures and that possibly an 18-caliber barrel might be optimum; however, he never indicated he had actually built an .18 Extruder. Langsford sent me a very professional and balanced article on the Myra Extruders, written by Warwick Mitchell, and published in Australia's Guns & Game magazine. Mitchell had an opportunity to really wring out the .20 Extruder. He found that depending on the type of .22 LR round being fired, velocities did increase in the Extruder from 25 to 60 fps; penetration in wet newspaper increased from 3-4 cm; trajectories were flatter by about 1" at 100 yards; accuracy ranged from excellent to fair depending upon the parent brand of .22 LR being fired, and the .20 Extruder did deliver more impact energy on the distant rams at the silhouette range.
Mitchell's conclusions were the real potential of Langsford's squeeze bore Extruders lay in developing the smaller, more effective, . 17 or. 18 bore sizes, but that the $475 cost of a new Myra barrel hardly justified the slight improvement offered by the .20 Extruder over a conventional .22 Long Rifle.
While the appearance of the .17 HMR and the .17 Mach 2 made the further development of the Extruder concept unnecessary, the late Arthur Langsford with his remarkable "Extruders" deserves a prominent place in the archives of rimfire history.
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