07 February 2007, 06:00
boom stickgreat 338-284 info/loads/ballistics. watch out 338-06!
338-284 Canadian KCG
By Greg Matthews
Handloader, March-April 1993
While Europe is traditionally the home of innovative cartridge design, it was the English who pioneered the .33-caliber rifles. In Europe, barrels with an 8.6mm (.338 inch) grove diameter are almost nonexistent. Presumably this is because this bore size falls about half way between 8mm and 9mm. One easily identifiable exception is the 8.15x46R target cartridge. This old round was introduced between 1890 and 1900, and while most similar cartridges have long been obsolete, the 8.15 is still listed in the RWS catalog. Apparently there are still many old hunting and target rifles and combination rifle/shotguns chambered for the 8.15 cartridge, hence its continuing production. It even rates a mention in the RWS handloading manual, Wiederladen. Flatnose target bullets around 150 grains are available, so at least for now, Europe’s answer to the .30-30 WCF is in no danger of immediate retirement.
British gun makers were much more serious to their approach to .33-caliber cartridges. Groove diameters varied because no standards had been set at the time. The very popular .318 Westley Richards was loaded with .330-inch bullets. Its “.318†designation came from the British practice of naming new rounds using the bore rather than the groove diameter. The perfect example is the .303 British which has a groove and bullet diameter of 311 inch.
Another lesser known but still well-respected cartridge is the .333 Rimless Niter Express. Whereas the .318 is slightly shortened version of the .30-06 case, the .333 NE and the .280 Jeffery were based on the .404 Jeffery case. The larger diameter rimless .404 cased afforded much more powder capacity, yet the British chose to load many cartridges quite conservatively for hot weather shooting in Africa and India.
Like many European rounds, there was also a flanged (rimmed) version for single shot and double rifles. The 250 and 300 gram loads were slightly slower than the equivalent rimless rounds. This too was common practice as double rifles preferred lower breech pressures. To confuse matters further the two .333 cartridges were actually loaded with 333-inch bullets.
Although Jeffrey’s .333 cartridges are now obsolete, they were always more successful than the later .33 Belted Rimless Niter Express. SBA’s .33 NE failed mainly because the light 165-grain bullet lacked the ability to knock down medium game. A very similar round, the .26 SBA are also loaded with an unusually light 110-grain bullet. It also failed to generate sufficient interest, yet had the makers produced suitable bullets the outcome could have been very different. The .33 SBA loaded with modern propellants should be almost identical to the .338-284.
American development of .338 cartridges had a lower priority. This is hardly surprising consider the number 0f .30, .32 and .35 caliber rounds already in existence. The old 1886 Winchester lever action featured a new .33 Winchester chambering in 1902. In turn the .33 Winchester was superseded by the more powerful .348 WCF in 1936. The .33 WFC was nothing more than the even older .45-70 case necked to hold standard 338-inch bullets. Hornady still makes a 200-grain flatnose suitable for lever actions in .33 WCF. These bullets plus modest charges of modern powders will easily reproduce its factory velocity of 2,200 fps. The .33 WCF is no big game rifle (by African standards), yet it is reasonably effective at close ranges.
The obvious ability of the .318 Westley Richards and the .333 NE prompted American Wildcatters to build their won .33-caliber rifles. Many early rifles were fitted with .333 inch barrels for use with British bullets. Of these, the .333 OKH amply demonstrated the capabilities of this bore size to U.S. hunters. In effect it was very similar to the .318 Westley Richards, but practicality has never stood in the way of a new wildcat.
In 1958 the magnum cartridge frenzy resulted in Winchester’s introduction of the .264 and .338 magnums. In the past I have questioned the need for either of these rounds especially when they only duplicate the European 6.5x68 and 8x68S magnums. No doubt the existence of the 458 Winchester parent case was a major factor in the introduction of the 338 Winchester Magnum. Not be outdone, Mr. Weatherby created a similar belted round, the .340 Weatherby Magnum. Obviously any cartridge capable of propelling a 200-grain bullet at 3,200 fps or 1,000 fps faster than the old .33 Winchester must be a very capable came taker. At the same time the .340 consumes vast quantities of powder and kicks hard enough to deter some potential buyers.
Wildcatters are always interested in changing the shape and size of cartridges to modify their performance. In the old days cartridges just seemed to get bigger and bigger. For example the next step after the .340 Weatherby is the .338-378 Weatherby in shorted and full length versions.
In recent times more experimenters are returning to the .338-06. It is hard to imagine the .338-06 becoming a factory round due to its similarity to the .35 Whelen. Although uch loved by many of its users, the .35 Whelen is another example of a capable yet superfluous cartridge. The equally useful 3.9x62 has been doing the same job in Europe and Africa since 1905.
If there are few openings for long cased .338 wildcats, there may be more opportunities for shorter cartridges. As present the 358 Winchester and the .350 Remington Magnum are out of favor with rifle manufacturers. In an effort to provide a .338 round suitable for lightweight carbines, Hawaii-based gunsmith Mark Pinkston has necked the .284 Winchester up to .338. the .338-284 Canadian KCG is named after Pinkston’s company, Kailua Custom Guns. Its suitability for north American game prompted the addition “Canadian†part of the title. For this article I think we might shorten this to just .338-284.
The 338-284 sounds like a good idea, but where can you buy the components? Clymer Manufacturing Co. has drawings of the chambered reamers and will supply a reamer and headspace gauges on request. Mark Pinkston (P. O. Box 635, Kailua, HI 96734-0635) is able to supply chambered and threaded McGowen barrels.
Barrel maker Harry McGowen makes a complete range of button rifled blanks. His list of chamberings is quite extensive, so if you need an unusual wildcat it may be cheaper to buy a semi-finished and chambered barrel. My chambered blank was threaded for the Winchester Model 70. After testing another Parker-Hale action sporter it seemed more appropriate to employ a short action, hence the AS Model 70. Although the Model 70 is no correctly scaled for cartridges up to .308 WCF, it doe have a small spacer at the rear of the magazine. Removal of the spacer and modifications to the bolt stop will permit a valuable 1/3 inch extra magazine length.
The barrel also came threaded for Pinkston’s PPRS recoil reducer. Like many others, I have always doubted the value of such a system, but after testing an earlier sampled fitted to an 8x57mm barrel, I too am a convert. The PPRS is a simple screw on device that has recently been patented in the U.S. Although the actual recoil reducer is not new, its novel barrel threading device allows reasonably talented amateurs to thread the muzzle without need of a lathe. In the near future the PPRS will be available in kit form to gun tinkerers.
A Garrett Accur-Lt. fiberglass stock was then fitted, bedded and painted. Almost every rifle in the modest Matthews collection is now similarly equipped. Most Australian hunters live in large coastal cities. Stock that warp in drier inland conditions have ruined many hunting trips, hence the trend toward synthetic stocks. Garrett stocks are all hand laid-up with completely filled fiberglass or Kevlar shells. Each is fitted with alloy bushings to prevent compression when the stock screws are tightened.
Garret blanks are sold in blank form or completely finished and bedded at the factory. I am not convinced it is wise to buy a factory painted by not fully fitted stock, because home fitting often results in minor blemishes. Amateur gunsmiths capable of final inletting and glass bedding will find all finishing instructions and supplies are available from Garret Accur-Lt. (l1413 B. E. Oliver Ct., Fort Collins, CO 80524).
Winchester cases in .284 are no longer readily available in Australia. the Winchester agent has reduced the stock inventory and deleted some slow selling lines. This means .284 wildcat owners must buy whole ammunition and remove powder and bullets before reforming to a new caliber or order new brass and wait for the next shipment. Fortunately for US shooters, the situation is much brighter with brass still being stocked by various jobbers and component suppliers.
At present .338-284 dies are made only by Huntington Die Specialties. Huntington makes all RCBSs custom dies and because die making reamers are already available, any future die sets will be sold at the usual custom die price. One necessary addition is a tapered neck expander. Winchester .284 cases must be neck expanding to .338 inch before final fireforming. In a properly headspaced .338-284, the bold will close with very slight resistance. This means the case is held firmly between the shoulder of the chamber and the bold face. The first shot will iron out any wrinkles and the case is read for work. Mr. Pinkston mentions a fireforming load of 16 to 18 grains of Bullseye and any cheap bullet. Alternatively I used a 200-grain flatnose and 55 grains of IMR 3031. Either load produces the same result.
Two new .338 bullets have been introduced recently by Speer. Of these, the 225-grain softpoint boat-tail would seem appropriate for the .338-284. Speer’s other offering, the African Grand Slam solid, is one of a number of similar full metal jacket (FMJ) projectiles now available. Grand Slam solids are made from gilding metal bars turned to their final shape. the hollow core is filled with a super tough solid tungsten carbide insert. A tungsten core brings the finished bullet up to its required weight without resulting in an overlong bullet, which would be the case if the entire bullet were made of gilding metal.
Sierra’s 250-grain softpoint is a favorite for many hunters. Pinkston’s own .338-284 is capable of 1-inch groups at 200 yards with the Sierra. More common in Australia are the five .338 bullets made by Hornady. These include the 200-grain Spire Point and flatnose, a very efficient 225-grain Spire Point plus 250-grain roundnose and Spire Point styles. For really tough game there are 210 and 250-grain Partition bullets from Nosler.
Powder charges for the .338-284 were formulated using .338-06 loads as a guide. Both cartridges are roughly equal in powder capacity depending on throat length. While some authorities seem to favor slow-burning powder like IMR-4831, my .338-284 preferred medium burning rate propellants. Really slow burners merely filled the case to capacity without producing sufficient velocities. In all I tested the .338-284 with 10 different powder and the range of Hornady and Nosler bullets. While some results were uninspiring, the better loads were not far off .338 Winchester Magnum speeds.
One surprisingly good bullet is the 200-grain Hornady flatnose. Although it tends to run out of puff at relatively short ranges, this bullet achieved remarkably high velocities, some in excess of 2,900 fps. In the old days, my grandfather’s .308 WCF was loaded with flatpoint Tombac steel jacket Norma 150-grain flatpoints. These rather homely Normas would tear fist-size holes through smaller wild pigs. the 200-grain .338-inch Hornady flatnose bullets have a similar result at slightly longer ranges.
Case capacity loads of Winchester 785 or IMR-4831 were capable of only around 2,400 fps. At the other end of the scale stiff charges of Mulwex AR-2206, W-748 and AR-2208 had bullets moving at 2,800 to 2,900 fps.
Although not as economical as the 200-grain Hornadys, Mr. Nosler’s 210-grain Partition bullet is capable of excellent speeds while retaining its most important property, controlled expansion. Nosler’s latest loading manual lists 2,3020 fps as the top speed obtained from their 24-inch Wiseman 338 Winchester Magnum test barrel using 76 grains of Reloder 19. The same bullet fired form the .338-284 clocked 2,880 fps when driven by 57 grains of IMR-4064. AT best the .338 Winchester test barrel was capable of only an extra 140 fps with the addition of almost 20 grains of powder. Groups of these premium projectiles often broke the one-inch barrier at 100 yards.
Hornady’s 225-grain Spire Point also zipped along at remarkable speeds. Medium burning rate powders, IMR-4064 and AR-2208, chronographed close to 2,800 fps. All powders except W-785 and IMR-4831 drove the sleek Hornadys along at over 2,700 fps. I thought little of this until I consulted a Federal catalog for comparisons with the .338 Winchester Magnum. the Federal 225-grain factory load is rated at 2,780 fps from a 24-inch barrel. Perhaps the factory loads are relatively mild.
In comparison, .338 Winchester Magnum loads from Hornady’s Handbook Number 3 credit their 225-grain Spire Point with 2,800 fps using 74 grains of H-4831. From this information it would seem reasonable to assume the .338-284 is very similar to .338 Winchester Magnum factory loads, but still inferior to maximum hand loads.
Accuracy of the 200 and 225-grain bullets varied from 1 to 1.5 inches for three-shot groups. Recoil from both bullets was almost nonexistent thanks to the extremely effective muzzle brake. Other shooters simply did not believe the effectiveness of the recoil system until they fired a few shots.
Projectiles heavier than 225 grains, for most jobs, are too heavy for local game. Game including pigs and deer are no match for 200-grain bullets. About the only game worthy of heavier bullets is the Northern Territory water buffalo. Some of these animals are extremely tough to down, hence my interest in Speer’s new 275-grain Grand Slam solid.
The 250-grain Hornady pushed back with a little more authority yet was still not uncomfortable to shoot form a bench without a shooting jacket. Groups included some nice sub-MOA three-shot efforts. Accuracy fell away when very stiff loads were tested. Tight extraction was almost always accompanied with vertical stringing. Groups opened 2 to 2.5 inches in height with almost no horizontal dispersion. Velocities followed the same pattern as before with only the slowest varieties failing to register speeds once thought unlikely for such a small case. The best velocity of 2,644 fps came from 54 grains of IMR-4895 with 250-grain bullets.
According to my latest Remington catalog, the 250-grain .338 Winchester load should reach 2,y660 fps. Don’t ask me how such modest charges in the .338-284 are capable of almost identical speeds. Perhaps we could liken this comparison to many other .30-06 capacity cases and their nearest magnum relatives. Without the aid of a long barrel the velocities actually derived from many magnums is not much greater than standard cases.
Thanks to its fiberglass stock and short action, the Model 70 is an excellent mountain rifle. Just the thought of a .338 Winchester Magnum equivalent cartridge in a featherweight rifle with minimal recoil almost defies imagination, doesn’t it?
.338-284 Canadian KCG
bullet (grains) powder charge (grains) velocity (fps) remarks
200 Hornady Spire Point AR-2206 55 2,829
IMR-3031 55 2,843
IMR-4895 57 2,820*
AR-2208 59 2,833*
200 Hornady roundnose RS-12 58 2,885
W-748 60 2,888 near maximum
IMR-4831 59 2,458 low velocity
W-760 62 2,766*
210 Nosler Partition IMR-4064 57 2,714*
W-785 62 2,473*
225 Hornady AR-2206 54 2,711
IMR-3031 54 2,718
IMR-4895 55 2,727
IMR-4064 55 2,715
AR-2208 56 2,785
RL-12 56 2,788
W-748 85 2,763
IMR-4831 59 2,444* mild
W-760 62 2,721*
W-785 62 2,530 mild
250 Noslser Partition AR-2206 52 2,616
IMR-4895 54 2,644
2-748 56 2,579
IMR-4831 59 2,424*
250 Hornady Roundnose IMR-3031 52 2,588
AR-2208 55 2,602
RL-12 55 2,592
W-760 60 2,426
250 Hornady Spire Point IMR-4064 54 2,577
W-785 62 2,384* mild
*Capacity Load
, you will ExCeeD it! 
and with less recoil. 
