When Remington’s formidable .416 Magnum was introduced a few years back, the Wilmington marketing gurus were astonished by its enthusiastic reception. Contrary to their expectations, the Custom Shop rifles were not only snapped up as quickly as they became available, but the company had to halt sales for a time to let production of the new ammunition catch up with the unexpectedly heavy demand. There was no point in trying to sell rifles if there is no ammo available for them.

Ruger’s handsome .416 Rigby has enjoyed a similar welcome among American gunners. Originally, the Southport firm’s Model 77 Mark I1 Magnum was chambered for two rounds: the .375 H&H and the Rigby. Predictions were that four .375-caliberrifles would be sold for every .416, but again, projections were far off the mark. To date, sales of both calibers are running almost neck and neck, with the .416 Rigby enjoying a slight edge. In addition, none of the 77 Magnums languish on dealers’ shelves very long; consumer demand remains much stronger than anticipated.

Most of those Rigbys, like the bulk of the .458 Winchester Magnum rifles manufactured here since 1956, will probably never leave the country. They will see lots of use, though, as their delighted owners punch holes through steel plates, blow boulders apart and try them out on everything from deer and elk to moose and grizzlies.

A certain number will find themselves pitted against critters more worthy of their potential, of course, but whether a Rigby is used to impress the troops at the local range or take on dangerous game at close quarters, anybody who buys one should be prepared to shoot it a great deal.

Mastering a rifle that recoils with all the verve of a pile driver requires more than just a couple of quickie familiarization sessions at the range – and that’s where cast bullet loads come in. Granted, anyone who can afford a Ruger Rigby probably won’t be too concerned about the cost of ammunition for it, but frequent trips to the range spell extra barrel wear and alloy slugs are much easier on lands and grooves than thick-jacketed solids.

Unfortunately, the number of .416 cast bullet designs available is severely limited for the time being. New moulds will be forthcoming from both Lyman and RCBS any time, but right now there are only two in my inventory, both manufactured by NEI, Inc. The catalog lists them as 370-416GC and 330-416GC. Cast from used Linotype, unsized bullets from the double-cavity moulds weigh 376 and 332 grains, respectively. According to an LBT lead hardness tester, they average 23 on the Brinell Hardness Scale.

Although many moons have come and gone since the .416’s debut, none of the larger mould makers were too enthusiastic about the caliber. Like the rifle manufacturers, they weren’t convinced there would be much of a market for them. Besides, as they liked to point out, there weren’t any .416- caliber gas checks around, and there wouldn’t be any point in creating old fashioned, plain-based bullets these days.

Of course there weren’t any .416 gas checks. Why manufacture gas checks for nonexistent bullet moulds?

So the seasons came and went, and everyone continued sitting on their hands, waiting for the other guy to make the first move.

NE1 got into the act at Gil Sengel’s urging. With a new .416 Remington to test, he designed a couple of bullets in the caliber and the clever chaps at NE1 machined the cherries so they would accept .44-caliber gas checks.

The idea of marrying .416 bullets and .44-caliber gas checks resulted in a plethora of frowns and head-shaking at first, but the odd coupling worked just fine. Both Hornady and Lyman checks have been employed with the NE1 bullets and perform equally well. Although the outside diameters of the little copper discs mike .433 and .425 inch, respectively, once they are fitted to the bullets’ bases, the slightly oversized missiles slip into the necks of unsized, fired cases without any fuss. Best of all, they deliver excellent accuracy with most loads.

Exactly how the checks squeeze their way down the bore, I can’t guess. Neither have I learned whether they stick to the base of the bullet or drop off after they leave the muzzle behind. None have been recovered, despite all the time I have wasted searching for them, leading me to suspect that the majority probably stay with the bullets.

In the test rifle (for a description of the Ruger and its capabilities with jacketed loads, see Rifle No. 131), the heavier of the two bullets proved slightly more accurate most of the time. There wasn’t a great deal of difference between their average groups, though, and when backed by a powder/primer combination it liked, the 332-grain bullet was capable of near-MOA performance. Its track record left no doubt about its potential. It just seems to be choosier about its loads, that’s all.

Why a light bullet at all?

Two reasons: First, loads featuring the 332-grain bullet recoiled much less than those propelling the heavy bullets, making the former ideal for getting-acquainted loads; second, Hornady and RCBS are both going to offer jacketed spitzers in the 340 to 350- grain range for .416 shooters interested in hunting North American game. Why practice with a heavy bullet if the intention is to depend on a light one in the field?

Both bullets were loaded unsized and hand lubricated. Fresh from the moulds, the waistline of the 376-grain missile measures .420 inch; the lighter bullet mikes .418. Slugging the Ruger’s bore revealed a groove diameter of .4165 inch, well within factory specs (.416 to .418 inch).

Thanks to LBT Blue lubricant, leading was never a problem. In fact, it only appeared once, and that was in the form of a slight flash around the muzzle.

In that particular instance, the cure was to reduce the powder charge and add a filler. Those steps not only left the bore mirror bright, but improved accuracy as well.

The original charge featured 110 grains of H-870 behind each of the bullets. Federal cases and primers were employed. Velocities, measured 25 feet from the muzzle, averaged 2,300 fps for the heavy bullets and 2,333 fps for the light ones. Extreme velocity spreads were very small, but accuracy was mediocre, ranging from 3 to 3% inches at 100 yards, benchrest. As noted, a slight ring of bullet metal was left around the muzzle.

The next load saw the powder charge reduced to 105 grains and topped off with five grains of GOEX Fg (by volume).

Black powder? Used as a filler?

Sure, why not? The ancient propellant meets most of the recognized criteria: it’s bulky so only a small amount is usually required to plug a gap between the main powder charge and the bullet’s base; it compresses easily; what little fouling it might leave is blown out the muzzle by all the burning gases behind it, and it seldom raises pressures or velocities much. All in all, black powder can make a very effective filler at times. Sad to relate, this wasn’t one of them. When coupled with H-870, the extreme velocity spreads widened to 80 fps and groups expanded another inch. The lead flashing disappeared though.

A switch in fillers was indicated. Another batch of loads was put together, featuring the same 105-grain charge of H-870, but substituting a few grains of Winchester’s Super Grex as a filler. Velocities dropped to 2,068 fps for the heavy bullets and 2,109 fps for the 332-grain bullet. Groups tightened considerably: 1% to 1% inches for the 376-grain slug and a series of 1% inchers from the light projectiles. One three-shot cluster (all the magazine holds) of 376 grainers chopped out a single, ragged hole, but that was chalked up to luck.

Those experiments were described to emphasize that there may be more than one way to solve a problem. Anything is worth trying so long as pressures are held on the safe side. Incidentally, those cited H-870 loads were the only ones in the entire series that ever left any hint of leading.

At present, there are only three sources of Rigby brass to the best of my knowledge: A-Square Company (One Industrial Park, Bedford KY 40006), the Federal Cartridge Company (900 Ehlen Dr., Anoka MN 55303) and Huntington Die Specialties (Box 991, Oroville CA 95965). A-Square and Huntington market Norma cases. Federal’s are nickel plated. If plating isn’t carefully done, cases so treated can cause problems when forced into a sizing die. So far, none of the Federals show any signs of peeling or flaking, and every one has been fired and reloaded more than 40 times.

Longevity of both brands is the best of any I have ever handloaded. So far, only three Federal hulls have required trimming. None of the rest show any signs of stretching, thanks, no doubt, to the moderate pressures generated in them.

Although there have been no split necks or signs of gas leakage around primers, the pockets are beginning to wear. Now, when a primer is seated, there is noticeably less resistance than there used to be. Guess it’s time to toss those cases in the salvage bin.

Filling fired Federal cases to the brim with W-760 required 127.7 grains. Norma hulls averaged 129.2 grains. The working volumes of both are considerably less, of course. Without the aid of a drop tube, 114 grains of H-870 can be crammed beneath a 400-grain jacketed bullet when the latter is seated to its normal depth in a Federal case. If a shorter, 300 grainer is seated, another two or three grains of the same powder can be added to the charge, but in both instances, the powder will be compressed slightly.

Since cast bullets, weight for weight, are usually shorter than their jacketed brethren, maximum practical working volume of the Rigby hulls is up around 120 grains, more than needed to duplicate factory ballistics with most suitable powders. As a result, the majority of the loads listed in the data table depend on an inert material, Super Grex, to fill the air space between the bullet’s base and the top of the powder charge.

As luck would have it, I just finished the .416 range tests when a couple of other filler materials came to my attention. Like Super Grex, they were created to serve as shotshell buffers and are marketed by Ballistic Products, Incorporated (20015-75th Avenue N., Corcoran MN 55340). One, the Original Shot Buffer, is white like Super Grex and gives similar results when used in test loads. Its companion is pepper colored and listed in the firm’s catalog as Special Mix #47. It is denser than its stablemate and when used as a filler, tends to increase a load’s velocities a few feet per second more too. If Super Grex is difficult to obtain in some locales, either of the Ballistic Products’ buffers will make practical substitutes.

When seated in the cavernous Rigby hull, the bases of both NE1 bullets were just about even with the case shoulders. Depending on their bulk, most powder charges weighing 105 grains or less either failed to touch the bullets’ bases or barely did so. About 10 grains (by volume) of Grex were added to those loads with the aid of a measure designed to dispense black powder. Seated bullets compressed the filler sufficiently to keep the powder column beneath it back against the primer flash hole where it belonged.

Like so many big bore sporters, the Ruger is exceptionally accurate. With its Leupold variable set on 5x, its best factory-equivalent jacketed loads can keep a magazine full in one inch at 100 yards from a rest 80 percent of the time. The best cast-bullet combinations cut 1% inches, sometimes less, when 300 to 400-grain bullets are driven to 2,300 fps or faster.

Some of the latter loads, as the data table indicates, were tested using open sights, primarily to see if their bullets were striking the target where their jacketed counterparts had. Those 3% to 4-inch groups noted in the “remarks” column represent the best I can do with open sights. Someone with sharper eyes could probably improve on my performance.

When loads built around the 376-grain bullets were fired from a rest, I could expect fairly consistent results on the target for 20 rounds or so. After that, the recoil’s battering began to get to me. After 30 rounds, most groups were decorated by an uncalled flyer. When loads based on the 332 grainer were tested, flyers didn’t appear quite as soon, but they showed up eventually. Sometimes as many as 40 rounds were launched downrange before recoil fatigue made itself felt. Once I became aware of my limitations, range sessions were limited to 30 rounds to prevent the results from being skewed by my inability to control the rifle properly.

When jacketed bullets are seated in the man-sized Rigby cases, the entire reloading process is pretty straight-forward. Seating slightly oversized bullets equipped with .44-caliber gas checks called for a slightly different approach.

Nobody makes a neck-expanding die for the Rigby case yet so, like the NE1 bullets, fired cases were left unsized. At the moderate chamber pressures churned up by typical Rigby loads, case expansion is minimal and fired cases can be rechambered with ease. Nevertheless, the hulls expand enough to ease the task of seating those larger-than-usual bullets. Both slid home with a minimal amount of resistance, just enough to ensure a snug fit and an adequate bullet pull.

Because cases aren’t resized, depriming must be accomplished with the aid of a punch (one designed to decap .30-06 cases works just fine). That adds a few more minutes to the process, but not enough to complain about.

Although both NE1 bullets were designed with crimping grooves, they couldn’t be used. Loaded rounds wouldn’t chamber in the Ruger until bullets were seated so that the front of the forward driving bands were even with the case mouths. That gave an overall loaded length of 3.5 inches with the heavy bullets in place and 3.4 inches for rounds featuring the 332 grainers.

Even though the lighter bullets were slightly shorter than the heavyweights, their profiles were blunter, their ogives didn’t taper quite as gradually as those gracing the 376-grain design. As a result, both bullets’ noses rested against the rifling when the rounds were chambered, despite the slight difference in total lengths.

When the bullets were seated deeper, groups began to expand. Even though that probably won’t prove true in all rifles, the Ruger’s reaction to seating depth experiments serves as a reminder that they are usually worthwhile.

Ideally, finger-length cartridges like the .416 Rigby are accommodated most comfortably by presses like the RCBS Big Max, the Redding Ultramag or Lyman’s Orange Crusher. They are all endowed with plenty of room inside their frames. Standard-sized presses can handle the 3%-inch rounds, but bullet seating is a problem. Trying to start an inch-plus bullet into a 2.9-inch case is impossible unless the seating die is backed out of the loading press about half an inch. By inserting the bullet’s nose up into the bottom of the die first, it’s possible to hoist the base over the case mouth and center it. At that point, the handloader may either raise the ram and start the bullet into the case neck (the approach I prefer) or simply screw the die back into the press, raise the ram and seat the bullet as usual. The entire procedure sounds more complicated than it is. After the first two or three bullets are seated, the extra motions quickly become routine.

Bulky, slow-burning powders work best in Rigby’s maxi-case. Propellants with burning rates ranging from IMR-4831 to H-870 are the most useful, IMR-4350 and Brigadier 4351 are borderline. Suitable charges of either leave a generous airspace between the top of the powder column and the bullet’s base. Although adding a filler can solve that problem neatly, in the long run, it’s best to use a bulkier powder and less filler.

Of the propellants tested, it’s a tossup between IMR-7828, H-450 and H-1000 as to which is the most effective. Each delivered tight groups when bullets were driven at or near factory velocities. Ignited by magnum primers, they burned clean and required the addition of very little filler material.

Accuracy with the H and IMR-4831 in the test rifle was acceptable, but nothing to write home about. Topped off with Super Grex, H-870 usually kept all its bullets in 1% inches, but velocities were 200 fps or so on the slow side. As noted previously, charges heavy enough to duplicate factory ballistics left flash leading and groups , expanded unacceptably.

Although a few loads were mated with standard primers to satisfy my curiosity, the majority depended on Federal 215M and Remington 9%M caps. Winchester’s WLR primers were hotter than the Remington 9% while the Federal 215Ms had noticeably more gusto than their competitors in the green and orange boxes. In general, magnum primers narrowed extreme velocity spreads, increased velocities and enhanced accuracy.

For reasons nobody has explained satisfactorily, most big bore rifles shoot cast bullets accurately and Ruger’s .416 Rigby is no exception. In fact, I’ve never seen a sporter in any caliber digest them as readily. Although the two cast designs employed in the tests didn’t group quite as well as jacketed bullets at similar velocity levels, the differences usually amounted to .5 inch or less. Needless to say, just because I didn’t stumble on a better, more accurate combination of components doesn’t mean one doesn’t exist. No attempt was made to fine-tune any of the listed loads. They should be regarded as points of departure for further experimentation in other rifles.

As the range sessions were drawing to a close, the mail brought a couple of interesting jacketed bullets from Northern Precision (337 South James Street, Carthage NY 13619). One weighed 370 grains, featured a .035-inch jacket and a roundnose tip moulded from white polyethelene. The other was a 300-grain roundnose with a thinner jacket and a lot of lead showing up front. A few loads were made up for each to see what they could do on paper. Again, no attempt was made to send them out the barrel much faster than 2,400 fps, even though the lighter bullet could have been hiked to 2,700 fps without too much trouble. Presumably, both designs were created to take on North American game, with the heavier constructed to penetrate deeply and hold together while the 300 grainer was beamed for thin-skinned animals. Well made and accurate, their loads were added to the rest for those interested in hunting something other than Cape buffalo and elephants.

It’s always tempting to push cast bullets as fast as possible, if for no other reason than to discover their limits. This time, it seemed more practical to approximate factory load performance, to match their recoil levels and trajectories so that range sessions, especially those dedicated to rapid-fire practice, would be as realistic as possible. That approach should also make the transition to jacketed-bullet loads easier when the time comes to head afield.

Editor’s Note: Subsequent to Al’s completion of this article on .416 cast bullet loads, RCBS is marketing a mould, 416-350FN, which produces a flatnose bullet with a nominal weight of 350 grains. A1 did a review of the mould on page 98 of our Shooting and Hunting Buyer’s Guide- 1992/1993.