Wildcatting the .375 Ruger
January 04, 2011
The author takes a good idea and makes it bigger--.416 to be exact.
Like any good wildcatter possessed with the common sense of a fern, my first impression upon seeing the new .375 Ruger was: "Gee, what can I use this unique new case for wildcatting-wise?" Never mind the cartridge's considerable merits as a .375; all I could think about was what kind of cartridge I could come up with by necking it up or down.
I think by now everyone knows that this .375 was developed for Ruger by Hornady and as such is among the latest batch of nearly a dozen new cartridges--both rimfire and centerfire--introduced in recent years by this innovative Nebraska-based reloading equipment and ammunition manufacturer.
The .375 Ruger is new as a commercial cartridge but not as a proprietary one. John Lazzeroni has that distinction, as he came out with the same basic case back in the early 1990s, but it was short lived. You see, the Ruger's case head is of the same diameter (.532 inch) as the belted H&H case with which we're all familiar. The difference is that, where the belt on the H&H case steps down .020 inch to form the headspacing surface, the Ruger case does not; it continues forward at that .532-inch diameter, and as such the entire body of the case is about .020 inch larger in diameter from head to shoulder.
That of course means the volume of the case--its powder capacity--is greater, all other things equal. So even though it is about a half-inch shorter than the belted H&H case, it actually has greater volume--though only marginally. The average capacity of the three different brands of .375 H&H Magnum cases I weighed came to 97.5 grains of water when filled to the case mouth, whereas the Ruger case held 100. Because of this, the .375 Ruger not only matches but exceeds the ballistics of the vaunted H&H round, and it does it in a standard--rather than magnum-length--action, which is its raison d'etre.
Obviously, that same advantage can apply to other calibers, and most notable in my mind was .416. And a similar comparison to the one just mentioned can be made using the .416 Remington Magnum, which is based on the full-length H&H hull, though "improved" in wildcatter jargon, by sporting less body taper, a sharper shoulder and a shorter neck.
The resultant case holds 105 grains of water, so the difference between the nominal ballistics of the .416 Remington and a .416 based on the Ruger case should be very similar. That rationale prompted me to go ahead with what, for lack of a better designation, is the .416 JRS.
I ran the idea past my friend George Sandmann, the guy who runs Empire Rifles. George volunteered to put together a rifle because it not only made sense to him but also because the majority of guns he builds for clients (all his guns are made to order) are in dangerous game calibers, so he knew that when I was through with it, he wouldn't be stuck with an oddball he couldn't sell.
By that time, the dimensional specs for the .375 Ruger had been registered with SAAMI, so what little changes had to be extrapolated from those specs to arrive at the reamer and chamber dimensions for a .416 version were easily computed.
Ditto for the reloading aspect. A call to Dick Bebee of Redding Reloading, a guy who's always interested in projects such as this, and arrangements were made for reloading dies.
The test platform was an Empire Rifles Mauser action with Wiseman barrel, Bell and Carlson stock and a Schmidt & Bender 1.5-6X scope set in New England Custom Gun scope rings.
The rifle George had put together was his standard grade African-style with the following options: dropped magazine to hold one extra round (four in the box instead of three), iron sights and a barrel band front swivel. George's controlled-round feed Mauser-type actions in both standard and magnum length, for right-handers and lefties, are built exclusively for him here in the States.
Extraction and ejection are purely Mauser, but the safety is basically Model 70 Winchester, with a horizontal-swinging three-position wing on the bolt shroud that withdraws the striker assembly from contact with the trigger sear. The trigger itself is manufactured in Germany by Recknagel and is similar to that of the Remington 700. It broke at a very crisp and creepless 31â„2 pounds.
The barrel is a 22-incher button rifled and fitted by Bill Wiseman, one of the most respected custom barrel and rifle makers in the country. The test gun wore a Bell and Carlson Aramid fiber synthetic stock with an integral aluminum bedding block. The gun arrived already fitted with a 1.5-6X Schmidt & Bender scope, and ready to go the test gun weighed 111â„4 pounds, about right for a rifle of this type, caliber and intended use.
Included with the Redding dies was a tapered expander that allowed me to neck up the .375 Ruger brass to .416 inch in one pass. I then sized the necked-up cases, adjusting the sizing die to just kiss the shoulder enough to give a little resistance to the down stroke of the bolt handle.
After running all the cases through the resizing die, I was ready to pick a powder and a starting load. Before doing so, however, I again checked the comparative case volumes of the .416 Remington Magnum and my .416 JRS.
Empty, the two cases are literally identical in weight: 260 grains. Filled with water to the case mouth, the Remington case holds 105 grains of water, the Ruger 100. But the .416 Remington Magnum case has a longer neck, so when I reduced the water lever in both cases to where it was even with the base of the neck--which is the real measure of case volume--both held 89 grains of water by weight.
The reason for these machinations was simple: with both cases being of identical capacity, I knew I could safely use any published starting load for the .416 Remington Magnum in developing loads for my wildcat.
Checking four reloading sources--Barnes, Hornady, Nosler and Speer reloading manuals--the consensus had Reloder 15 as the top-performing powder. Taking the starting loads listed in all four manuals for a 400-grain bullet and averaging them, I came up with 75.5 grains. The average maximum load was 80 grains on the nose.
Just to be safe, I started with 74.0 and loaded three rounds each in one-grain increments up to 79 grains, color coding the bases with felt tipped markers and recording each as I went along. With three rounds each of six
different loads, I packed up my shooting gear--including my Caldwell Lead Sled (I'm not stupid)--and chronograph and headed for the range.
I fully expected to match the nominal 2,400 fps listed for Remington's 400-grain factory load, and I wasn't disappointed. Big bore cartridges suffer less velocity loss than smaller calibers as barrels are cut back from the 24-inch norm used in establishing factory ammo velocities, so I figured if I could get 2,350 fps out of the test gun's 22-inch spout, that would essentially meet my goal. As it turned out, using Hornady's 400-grain softpoint, I achieved 2,405 fps with a mere 75 grains of Reloder 15--with no signs of excessive pressure.
The two bullets Sundra's experimented with so far are the 400-grain Hornady roundnose and the 350-grain Barnes' Triple Shock. At far left is the 400-grain Barnes, which he decided was too long.
For my second trip to the range I loaded up 20 rounds of that same 75-grain load of Reloder 15 to see what kind of accuracy I'd get. With big bore rifles like this, two-inch groups at 100 yards is more than adequate, but this rifle had no trouble averaging three-shot groups of 13â„8. And that's with the very first load I tried.
I have since experimented with what I feel is the most versatile bullet you can ask for in .416 caliber: Barnes' 350-grain Triple Shock X Bullet. Because X Bullets retain literally 100 percent of their weight, a 350-grain bullet should theoretically penetrate as deeply as a conventional or even a bonded core bullet of greater weight. Also, being of a spitzer configuration, it has a ballistic coefficient of .521, which is comparable, for example, to Hornady's 7mm 154-grain SST spire point boattail.
Again working with Alliant Reloder 15, 75.5 grains produced 2,570 fps in my 22-inch barrel, with a trajectory so flat that it makes 300-yard shots just as possible as with a 7mm or .300 magnum.
What's really amazing is that that particular load is 8.5 grains less than the maximum load listed in the Barnes' manual for the .416 Remington Magnum. And the 75-grain load for the 400-grain bullet is the average starting load for the .416 Remington. Talk about efficiency.
Could there be a .416 Ruger in the near future? I think so. Or for that matter, a .338 or 8mm, a .30 and a 7mm. It's just too cool a case for it not to be used as the basis for other calibers. And all would have the same benefit claimed for the .375 Ruger; namely, they would all provide belted-magnum performance and then some, from a standard length action.