Copper ammunition: getting the most bang for your buck
With a hurried need for copper ammunition, Will Pocklington turns to Corinium Rifle Range for professional assistance on a bespoke load
Copper ammunition only
I knew the time would come eventually; it just so happened to be a few weeks before my annual trip to stalk fallow in South Lincolnshire. “Oh, by the way, we’ve switched to copper ammunition only,” the keeper told me as we firmed up a date.
I’d been intending to move away from lead for a while; it was a case of waiting for the last of the soft-points in my cabinet to disappear. What I hadn’t anticipated was the difficulty in getting hold of lead-free factory ammunition in fairly short order. The price hike was unwelcome but expected; fruitlessly canvassing not-very-local gunshops to find something suitable was a tedious pain in the haunch.
It would be quite easy to get tangled in the detail of how this limited sample of shiny Cu performed, so let’s just say I hunted down a single box of 20, which grouped fine and performed well enough on 15 fallow, roe and muntjac shot in the chest at modest ranges over the next couple of months.
Then I ran out — and found myself compelled to explore alternatives. Might they offer improved performance? For me it was a break from the norm; stalking kit, gadgets and through-the-same-hole groups don’t really excite me, but if there’s ever a chance to bolster the likelihood of an easier follow-up or reduced carcass damage, I’m all in.
I’d heard much about the merits of going bespoke — hand-loading. I could also see the appeal of the process but haven’t the patience nor the confidence to do it properly. It’s a time thing, too — I’d sooner spend any spare hours outdoors, preferably with a rifle slung over my shoulder.
Option number two was to visit somewhere that could do it for me, so I called Paul Hill at Corinium Rifle Range on the Wiltshire/Gloucestershire border. I quite liked the idea of having a load developed specifically for my rifle — a very standard moderated Tikka T3X .308 with a 20in barrel and 1 in 11 twist rate, for those interested — and I knew Paul would be able to explain the process in simple, unbiased terms, based on many years of experience.
It turns out that you need to tailor copper ammunition to your circumstances as well as your rifle. We’re talking species, distances and shot placement. “A do-it-all copper round that performs consistently from 30 to 300m on everything from a fox to a red stag just doesn’t exist, particularly in factory ammunition,” Paul put it, matter of factly, soon after he’d welcomed me into his shooting lodge. “A bullet pushed very fast in order to perform at longer ranges can behave very differently at close quarters.” Point taken — I needed to be specific about intended use.
Paul continued: “If we’re really going to get the most out of copper ammunition, it’s not as simple as just going ‘fast and light for calibre’; we need to think about how the bullet imparts its energy into an animal. To do that we need to consider velocity and bullet weight but, more importantly, we must pay attention to bullet design.”
The design of a bullet, Paul explained, influences everything, from how quickly it transfers energy and what it does at the point of impact to the nature of the primary and secondary wound channels it creates. “Most of the disparity people experience when they switch from lead to copper is a result of differences in how the two materials transfer their energy. We know copper causes lethal tissue damage, but what it often doesn’t do so well is dump its energy into the animal. The wound is still lethal, but without the energy transfer and incapacitation, the animal can run, often for some distance until blood loss brings it to a stop.”
Many copper ammunition bullets are designed to retain their mass. Copper is also a hard material and so, when driven very fast, it follows that it can retain much of its velocity. “If a bullet retains both its weight and much of its speed, where is the energy after that bullet has passed through the animal? It’s still in the projectile. Traditional lead bullets, on the other hand, deform or break up. They might lose half of their weight or more, and they’re slowing down. The energy is left in the animal, causing massive hydrostatic shock that anchors the deer there and then prevents it from travelling far before falling over,” explained Paul.
He then ran through a few of the key variables at play. Pages could be written on each. Put simply, though, for my purposes — stalking roe and muntjac, where most shots are within 150m — he recommended refraining from really ramped-up velocities and a light-for-calibre bullet, instead opting for one that wouldn’t be an awful lot lighter than the 150-gr I am used to but would deform well, slow down and thus transfer energy into the carcass. It’s worth noting here that his advice is based, in part, on the field testing of a group of 13 stalkers who account for around 1,200 animals between them each year — none of whom, interestingly, plan to switch back to lead.
Next we considered my rifle more closely. Short barrels and slower twists rates can pose problems. My rifle has both. “Many of the new lead-free hunting rounds are better suited to rifle barrels with a twist rate of 1 in 8 or faster,” Paul told me.
“Calibres in 6.5mm, .270 and 7mm typically have faster twist rates, but what about your .308s, .243s and .30-06s? Many of the bullets on the market now have too long a shank to stabilise in calibres using a standard 1 in 10 or 1 in 11 twist rate, leading to accuracy issues, while others have to be driven so fast in order to stabilise that they can pencil through thin-skinned animals.”
On Paul’s loading table, amid empty cases, some primers, dies, a tub of powder and handwritten notes, he placed a box of bullets. They were of a spitzer shape with three cuts running a third of the way down the shank from a hollow point. “These bullets,” he said, “are designed to leave their energy in the animal more efficiently.” I took a closer look. British made — Virtus Precision.
Paul described how, upon impact, the cuts on the bullet help it to peel back and slow down, which ensures that all-important energy transfer into the animal while causing catastrophic organ trauma.
The process from constituent parts to loaded round involves several steps. Once the projectile type has been chosen, a computer programme is used to determine the specifications required so the bullet can be loaded in line with factory ammunition data — think seating depth, and the amount and type of powder. This serves as a solid starting point. Next, cases are cleaned, resized and primed, the propellant is weighed and added to each, and the bullets are seated. It’s the sort of thing that either really appeals to the inner nerd or really doesn’t.
Then it’s a 10-yard walk to Paul’s custom-built range, where the round is tested for accuracy through the rifle and each case is checked for pressure marks upon ejection. A chronograph is also used to measure muzzle velocity, check consistency across four or five shots and ensure the bullet is carrying enough speed to perform at its optimum.
For me, thanks to Paul’s catalogue of recipes — a product of doing this countless times for all manner of calibres and rifles, several of which matched mine exactly — that was the end of the process. It saved us time and removed some of the load testing.
With an average muzzle velocity of 2,881fps, a variation of 15fps across four shots and a group of just over 13mm at 100m, I was happy. On another day, if further tinkering was required, it would be back to the computer to look at how the velocity may be increased within defined parameters while maintaining accuracy.
This ability to load a round that safely exceeds CIP standards is seen by many as a major boon of hand-loading. The incremental process of changing the amount of powder in a case and seeing how that translates to accuracy and chronograph readings would follow. Experimenting with bullet seating depths might come after that.
It’s clear why visiting a proper facility to do this is favoured by many. I consider it an investment and plan to be back at Corinium again soon. Next time, the focus will be on testing my new, tailored rounds at extended ranges, ready for a week’s hindstalking in February. Until then, I’ll be interested to see how they perform during my efforts on the roe and muntjac back home.
Leading factory loads
Sako .308 Win Powerhead Blade Non-Toxic
Sako has developed the lead-free Blade bullet to meet the eco-friendly needs of stalkers and pest controllers. With its Blade tip, 100% pure ductile copper and five-stage terminal architecture, the Powerhead offers excellent performance on different shooting ranges and various sizes of game.
Winchester .308 Win Extreme Point Copper Impact
This is the perfect lead-free solution for stalkers who want a bullet that delivers deep penetration on medium and heavy game. The all-copper bullet provides near perfect weight retention for deeper penetration, even through bone and dense tissue, and a large diameter polymer tip means faster expansion for immediate impact trauma.
Hornady .308 125GR GMX Non-Toxic
Hard-hitting and deep-penetrating, the Hornady GMX is crafted from a copper alloy. Harder than solid copper, the copper/zinc alloy has been proven to shoot cleaner, foul less and deliver consistent, even pressure curves. The tough alloy material routinely retains 95% or more of its original weight and expands up to 1.5 times its original diameter.