Cast Bullets in the .416 Rigby
Date: Oct 01 2002
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.