The Best Elk and Deer Crossover Cartridges and Why

The mule deer is the classic Western deer. Locals take it for granted, but millions of Eastern deer hunters dream of hunting muleys. The wapiti is the West’s great game, which is also taken for granted by many resident hunters, while the rest of us fantasize about finding just one mighty bull.

Heading afield with a tag for each, the ultimate Rocky Mountain combo hunt, is the best the West can offer. Many folks who live in elk and mule deer country accept this as a normal autumn opportunity. They have the whole season to play with. Not so simple for most of us. The best times for each species don’t coincide, nor do the best habitats often overlap. Not to mention luck of the draw in getting tags, doubled if you want both elk and mule deer licenses.

A combo hunt is difficult to plan and tougher to execute, but can be done. I’ve headed afield with both tags in my pocket on numerous occasions, a glorious feeling full of opportunity. To be honest, I haven’t punched both tags very often. Doesn’t matter, I always expect to.

This story is not about the ideal mule deer rifle, of which there are many; or the ideal elk rifle, also many. Instead, about consciously choosing one rifle for both. Residents who commonly hold both tags probably don’t overthink this the way we dreamers do. They grab Ol’ Betsy and fill the freezer. I submit that the ideal elk/mule deer rifle deserves more serious thought, especially for us dreamers and rifle nuts.

Mule Deer Cartridges

Let’s start here. On average, muleys are heavier than whitetails. However, the largest northern whitetail is as heavy as any mule deer. So, practically, any cartridge considered adequate for a big whitetail is plenty of gun for mule deer. There is a difference. It’s not just that mule deer are often hunted in bigger, more open country. Mule deer are rarely hunted from stands. They are glassed and stalked, so the situation controls the shot. Average shots are longer and usually taken from field positions rather than the solid rests offered by most whitetail stands and blinds.

Even so, there are lots of options. I took my first few muleys with a .243. Since then, I’ve taken them with cartridges ranging from .22 centerfires to the .375 H&H and many with 7mm and .300 magnums. All worked, but not all were ideal. I’ve written that magnum cartridges are not essential for deer hunting. I’ll stand by that, including mule deer. You need reach, but cannons are not necessary.

The faster .25s (.257 Roberts, .25-06) with 115-120-grain bullets are awesome mule deer medicine. Likewise, 6.5mms with 140-grain bullets. The old .270 Winchester is still hard to beat. A strong case can be made for the less popular .280 Remington. A .30-caliber bullet’s weight, power and recoil aren’t necessary, but the .30s do work.

Because I use it a lot, some of my best mule deer—with the longest shots—have been taken with the great old .30-06—never a bad choice if you don’t mind the kick. You can—and I often have—used various magnums (old, new, short, long, belted, unbelted) in bullet diameters from .257 to .308. I’ve also used larger calibers, but neither they nor any magnums are mandatory for mule deer.

Bull Elk are Game Changers

For many hunters, elk is the largest game they will pursue. However, elk are not created equal. With today’s burgeoning elk herds, cows make up a large percentage of the harvest. Especially for resident hunters seeking winter meat. This is why many local hunters take a more casual approach to elk rifles than we out-of-state dreamers in search of just one bucket-list bull.

A cow elk offers some of the best venison, but she is not large. Often, just 25% heavier than a big muley. Any sensible mule deer cartridge is fine for cow elk. Spike bulls are bigger, and three-year-old raghorns bigger still. At this point I leave the 6mms and .25s behind, but most mule deer cartridges are still suitable for most elk.

Mature bulls change the game. The wapiti typically reaches maximum antler growth at between 8 and 12 years. Elk increase in body size and strength, until they decline of old age. Weights vary depending on feed, but a mature bull in good condition should weigh around 800 pounds and can exceed a half-ton. This is a horse—er, deer—of a different color that can be three or even four times larger than a big muley. A bull elk is powerful and tenacious. They’re in top condition from exercising up and down the hills. To cleanly take a big bull elk, you must hit him well, but also hard, with a good bullet of sufficient weight and construction to ensure penetration on such a large animal. Old, mature bulls are a small component of any herd. Chances of finding such a bull are not good, especially on public land. In my life, I’ve taken just a partial handful.

However, some are killed every year throughout elk range. If this is the kind of elk you dream of, then it seems to me you should be armed for the encounter. In North America, combination hunts aren’t common. In Africa, you almost always have multiple species on license. There’s no predicting what you might run into. So, if you have a chance to hunt elk and mule deer together, let’s borrow a page from the African rulebook: The rifle you carry must be adequate for the largest game you might take with it. For our discussion, that is a massive bull elk.

Elk Cartridges

I’ve never pushed the envelope on elk and have no desire to. The smallest cartridge I have taken elk with is the .270 Winchester. The largest, again, the .375 H&H. The former is adequate, but not overpowering. The latter is a real thumper on elk, but not necessary. Actually, because trajectory isn’t especially flat, it’s probably a poor choice for mule deer, and thus for an elk/mule deer combo. I feel the same about the .35 Whelen, a great elk cartridge, but overpowered for deer and not as flat-shooting as I like in open country.

For elk, let’s throw out my line about magnums not being needed. There are several standard cartridges that are adequate, but we must include a whole bunch of magnums. I have no qualms about the .270 Win., and I’ve taken as many bull elk with the .30-06 as with any other cartridge, and as many elk/muley combos. However, strictly for elk and hunting for big bulls, the medium magnums are hard to beat. I’ve used the 8mm Rem. Mag. a lot, and also several magnum .33s.

Which .33 depends somewhat on how much recoil you’re willing to accept, but the .338 Win. Mag. is a quintessential elk cartridge, hard-hitting and powerful. Any of the fast mediums could be used for our elk/deer combo. I will not include them because they are needlessly powerful for deer, and, absent brutal recoil, don’t shoot as flat as ideal. Most important, although wonderfully effective, they are not essential for elk.

Combo Cartridges

We’re not going to leave mule deer out of this discussion. Our mule deer might (or might not) be taken at longer range than our bull elk, but this is certain: A mule deer offers a much smaller target. This places greater emphasis on accuracy, and also on flatter trajectory, because on smaller animals there is less margin for ranging errors.

So, our combo cartridge needs to shoot flat, and must be accurate. Both are relative. A bull elk’s chest area offers a massive target. I am not an extreme-range shooter on game, but for both elk and mule deer I want to be confident to at least 400 yards. Mostly, I want to be certain I have enough power to cleanly take a bull.

For me, that’s a subtle and indefinable mix of velocity, energy, bullet weight, and frontal area. Not everyone agrees, but I rule out most 6.5mms (and all smaller calibers) on the last two. Today, because of bullet aerodynamics and action lengths, most modern 6.5s are limited to 140-grain bullets. I can’t rule out the 6.5 PRC and faster 6.5mms, but I submit that any 140-grain bullet is on the light side for big bulls.

My personal minimum is .270, .277-inch, preferably with 150-grain bullets. Because of 1:10 rifling twists, this is the bullet weight limit for traditional .270s: .270 Win., Wby. Mag. and the WSM. Because of higher speed, the latter two deliver more energy but, because of bullet weight, these are also sound minimums. The “new” .270s: 6.8 Western and 27 Nosler, have faster twists and push heavier bullets—up to 175 grains. We can’t shoot them in traditional .270s, but, for elk-sized game, added bullet weight moves the .270 from minimal to plenty.

Bullet weight is the 7mm’s advantage. The .284 hunting bullets have always ranged from 140 to 175 grains. For deer, I like faster, lighter bullets. For elk, and thus for our combo, I’m happy with anything from 160 grains up. Numerous 7mm cartridges have the velocity to play our combo game. My thinking starts with the .280 Rem. and goes up from there. Candidates include the short (unpopular) 7mm WSM and SAUM, .280 Ackley Improved and, of course, the 7mm Rem. Mag. and Wby. Mag. Don’t overlook the “new” 7mms, the PRC and 28 Nosler. Also specified for faster twist, these bring bullets of 180 grains and beyond. On the elk side of our equation, bullet weight matters.

So does frontal area, which brings us to the good old .30-caliber. A .308-inch bullet hits harder than a 6.5, .270 or 7mm, and the .30s also bring greater bullet weight. For deer, lighter and faster bullets are fine. For elk, I’ve generally loaded up good 180-grain bullets. With today’s heavier “low-drag” bullets, I’ve switched to 200-grain slugs; even better. Traditionally, .30-caliber bullets topped out at 220 grains. Hard-hitting and deep-penetrating, the heaviest .30 bullets were round-nose, reducing range and terminal performance. The popularity of long-range shooting has brought us longer, heavier .30-caliber bullets with incredible aerodynamics, again needing faster twists than the long-standard 1:10.

There are lots of great .30-caliber cartridges to pick from. Again, I’m not an extreme-range shooter on game, but for our elk/mule deer combo, I want enough velocity that I don’t have to do higher math for 400-yard shots. My cartridge list starts with .30-06, still a fine cartridge for elk and for mule deer. All the numerous .30-caliber magnums are in the running. Far the most popular is the .300 Win. Mag. I’m more of a .300 Wby. Mag. guy, but both are fast, powerful and effective. However, if I had to start over, and wanted to use the extra-heavy, super-aerodynamic bullets, I’d shift to a faster twist, probably in Hornady’s .300 PRC chambering. With all the fast .30s, we are probably over-gunned for our mule deer. That doesn’t matter, because we’ll be ready for our big bull elk at any sensible range.

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