The .220Swift was the first factory loaded cartridge that broke the 4000 f.p.s barrier, It was introduced by Winchester in 1935 and chambered in the M54 rifle. The basis of this round is the 6mm Lee-navy case that was necked down and more brass added in the case head region. The case is known as "semi-rimmed" but realistically it is a rimmed cartridge. When released in the late 30's with the factory loaded 48gn bullet at 4110 f.p.s it was the most potent of all commercial varmint cartridges. In the 1930's powder and barrel steel technology were poor. This had the effect of accelerating barrel wear in the throat area. This accelerated wear stemmed from three main area's; #1 Unsuitable powders (burning rates not ideal) meaning that handloaders often loaded to astronomical pressures to achieve the desired ballistics (65,000 cup not uncommon). The powders were very "hot" burning with little/primitive deterrent coatings. This extra heat combined with super high pressures "blow torched" the critical throat area. #2 Unsuitable barrel steels/barrels, The early Winchester swift barrels were manufactured from low grade "mild carbon steel" found on most rimfire barrels.
The barrels had a 1 in 16 twist with shallow lands, this coupled with mild steels poor powders and high pressures quickly eroded throats and barrels were soon shot out. The internal barrel finish also left a lot to be desired, many factory swifts being rough, leading to rapid accumulation of fouling and the resultant loss of accuracy. Winchester tried to alleviate the problem by fitting the "newer" swifts with stainless steel barrels which were less porous and less sensitive to erosion. It was commonly stated that the average barrel life of the early (chromoly barreled swifts) was in the order off 800 rounds. (No specification about loads ;cleaning technique; rate of fire etc.)
With the advent of modern barrel steels and powders and refined reloading technique most of the problems associated with the swift have been "cured". The swift still wears out barrels faster than "milder" cartridges like the 222 Remington through to the 22/250 Remington, but the fouling problems of the past are just a memory. New high quality stainless match barrels see more than 4000 rounds with loads circa 3900 f.p.s with 50gn bullets. When compared to the 8000 to 10,000 rounds expected for a 222 this may appear like a barrel burner. The figure of 4000 rounds will be reduced with "higher" pressure loads that match original factory specifications. (4110 f.p.s 50gn SMP). An area of criticism was that the swift was portrayed as a reliable deer slayer under most conditions, some writers even stated that non vital hits would put deer down. This is about as far from the truth as one can get with the .220! If the frangible 48gn Load made it between the ribs without breakup and obliterated the heart and lungs it did kill deer like chain lightening, but when any sort of bone got in the way they were destined to be cripplers. With the advent of "Trophy bonded" 60gn and 53gn "Barnes X" bullets this cartridge performs similarly to a .243Win on similar sized animals with noticeably flatter trajectory. Owing to the construction of the case the swift can be loaded to significantly higher *usable* pressures than most other cartridges that use other case designs.
The "semi-rimmed" case with extraction cannelure is arguably the strongest commercial case manufactured today. The thickness of the brass tends to "mask" pressures until you are getting way up there. A Sako that I experiment with does not show excessive pressure signs until pressures in the 60,000 cup range are reached. Primer pockets stay fairly tight and expansion rings are hardly evident. And with the new crop of thick cupped magnum primers flattening cannot be considered as a reliable measure of pressure. The strength of the case was dramatically illustrated when a "warm" load (W-W748 ball) was fired in 40 C temperatures. Bolt lift was sticky and upon ejection the Rem. 9.5M primer fell out. The case Looked entirely normal aside from some burnishing of the case base (hook extractor slot). It must be noted that this was not an overload, it was merely showing how temperature sensitive WIN-748 was in the .220. (The load was 40gn W-748 50gn Nosler B.T) This load shot very well in the spring temperatures of 20 C here in Aus. But up north (Bourke area) where temperatures regularly break the 40's it proved dangerously excessive. This temperature sensitivity was noted with other ball powders such as W-760 and W-785 when used in hot climates. Stiff primary extraction was noted on a .270Win, that showed "middle of the road" pressures down south. If pressures are held to the 55,000 cup range then case life is as good as if not better than similar capacity rounds like the 22/250Remington.


BULLETS:

The 23gn pill was an experimental bullet swaged from pure brass. Velocities were estimated at over 5000 f.p.s as they simply would not chronograph on the F2/M2 Chrony Chronograph. This load despite the mid-range pressures is hard on barrels and was only tried out of curiosity. Bullets occasionally stayed inside rabbits shot at 100yds. Larger game was not shot with this bullet as it was too frangible and would disintegrate inside #1 wet newspaper. The 40gn Nosler load listed provided some stellar game performance, to well past 300mt. Any rabbit caught napping inside 200 to 250mt was simply obliterated. When I first used this load, it reminded me of a Giant .17Rem. For surgical precision shooting this load was sighted in 1" high at 100mt, this provided exceptionally flat trajectory to about 250mt and bullets really hit the targets fast. This bullet shot to the same point of impact as the 50gn Nosler bullet, despite the varying weight and velocities. The loads that show heavy charges of AR2208 with this bullet are quite hard on barrels. The load that have given the most consistent results in the field and down at the range has been with the 50gn Nosler BT. When driven to 4000 f.p.s with either RE-15 or AR2208 (AR2208 is similar to IMR-4064) accuracy was generally sub 0.5" at 100mt and field performance resembled an atomic bomb. Game such as Kangaroo's (live weight up to 110lb or so) Goats, Foxes, Crows etc. have been taken with this load. In all cases it was found that the little billet of copper (base) continued to drive on through to leave a caliber sized exit hole. At 500mt bullets still expanded well still possessing enough energy to rapidly kill small varmints (rabbits). Match bullets from Hornady and Sierra, proved quite accurate in my rifle but tended to be a little to stiffly jacketed to perform in the field especially at the longer ranges. Killing power suffered noticibly once 350mt was reached, the bullets were simply not expanding violently enough. It must be noted that these bullets are not really designed for this use as they are MATCH bullets and therefore for paper punching. Bullets such as the Discontinued Nosler 60gn Solid base provided great shooting on windy days and the current crop of 60gn pills simply don't deliver in the field when compared to the Nosler. It's more bullet than required to kill rabbits Roo's and foxes here but the main advantage exists with the superb ballistics achieved for shooting in windy weather. It was noticeably less effected than the 50gn T.N.T over the long haul to 400mt (range shooting). Some ricochets were also observed at the longer ranges when velocity dropped off indicating that my lots may be a little to hard for most varmint shooting. The 62gn (SS-109) bullets were tried as a curiosity, This is the standard light armor piercing projectile that features a steel insert towards the nose point. The addition of steel to the bullet has increased it's length and decreased it's stability. The bullet was not stable in the 1 in 14" twist that is standard for most .224 caliber factory rifles. Bullets keyholed badly even at maximum velocities. The SS-109 fragmented inside ballistic gelatin this was caused by the exposed base turning the bullet into a giant soft point. The same fragmentation occurred with the 55gn FMJ Hornady (military copy) and massive destruction occurred (not unlike a soft point).


POWDERS:

The swift case tends to tolerate powder choice quite well, but to get optimal accuracy and the "advertised" speeds powder choice is a little more limited. Powders from AR-2206 (fast end) to W-785 (slow) were tried, and these generally fail in all area's except for the very lightest and heaviest bullets. Powders that gave best results were,
AR2208, IMR-4320;4895;4064, RE-15. The powders that are similar to IMR-4064 in burning rate gave the highest velocities coupled with the best accuracy, the slower powders such as W-760 Produced high velocities, but in cold weather exhibited large velocity spreads (300 to 400 f.p.s) which did nothing for accuracy. One load still managed to shoot below 1 M.O.A with this spread. Powders slower than W-760 produced more noticible bore fouling and required more frequent cleaning. Powders significantly faster than the RE-15 class (In the swift) failed to produce velocities of AR2208 and IMR-4064, and once "peak pressures" were reached subsequent increases in powder charge did little except boost pressures as velocity inched it's way up. With the 50gn Bullets AR-2208 produced the best accuracy with very high velocities, especially true with the Speer TNT. IMR-4895 Produced the most consistent results with 55gn Bullets (accuracy wise) more velocity could be had if a slower powder was used (IMR-4320 etc). With the 60gn Bullets RE-15 Topped out in the accuracy department and still managed to achieve high velocities (exceeding 3700 f.p.s).

ERRATA:

From test's it was found that the Norma cases tended to last longer than the Winchester cases and also tended to maintain tighter primer pockets.

The Norma cases held an average of 1.9gn less water than Winchesters trimmed to the same length. Magnum primers were used and added approximately 12 f.p.s to loads using the slow burners (W-760 AR-2209) but accuracy was at it's best with the standard Winchester "WLR" primer. Also note the velocity of the Speer "TNT" bullet, it is listed as 4096 f.p.s this is some 700 f.p.s above the Speer recommended maximum for this bullet. At no stage was any bullet break-up observed and groups were nearly as good as the loads with the Nosler projectiles. For the critics that claim that this cartridge is difficult to load for all I can say is that nothing could be further from the truth. Pressures rise uniformly and predictably with additional increase in powder charge. Accuracy and case life as good as any other cartridge that operates at such a high intensity. Particular care must be noted with case length (as with any other cartridge) as the main effects are diminished accuracy and increased pressures. If you can get Norma Swift brass at a good price, do it! It lasts far longer than the Winchester Brass and Remington.
All data was chronographed on a Chrony F2/M2 Chronograph at a distance of 10 to 12 feet from the muzzle.


DISCLAIMER:

The above loads were safe in **MY** rifles, to try and use them without reduction is downright dangerous! Reduce all 10 % and work up slowly.

PICTURES SOON TO FOLLOW



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