I have been doing a lot of thinking about copper bullets recently. I’m putting a new rifle together and want to make sure it’s future proof come the lead ban which whether we like it or not is probably inevitable within the next 5 years. I’ve also read a few threads where people are obviously confused about the switch and how to do it most effectively.
Here is my take on it all. I’m sure some will disagree but this is the logic I’m happy with.
I started by running some numbers. I know through my own experience with GMX, TSX, TTSX and LRX bullets that I need to achieve a TV of 2400 fps if they are going to expand reliably and kill deer quickly and humanely. The bullet manufacturers bang in about 2000 fps expansion but in my experience this is not true. Plenty of others have corroborated this, some even feel 2400 is a bit low. I don’t believe it matters whether you are talking about Barnes, Hornady or Noser, all their copper bullets behave in a very similar way.
So if you’re going to maximise the effective range of your rifle with a copper bullet you need to reduce the weight of the bullet you’re using, probably to the smallest available in your calibre, to launch it as fast as possible and maximise the range at which it drops below 2400 fps.
My humble 7mm08 currently launches a 150gr ABLR at 2740 fps. It’s still carrying 1000ftlb of energy at 700m and doing 1750 fps which I trust an ABLR to expand at. Now I’m not one to shoot deer at 700m, but I have shot injured deer at over 500m and like to have the option to do it reliably. I also enjoy whacking the odd steel plate at range.
Switch to the 110gr TTSX, the fastest bullet I can get in 7mm, and I can launch it at 3150 fps. It hits the 2400 fps threshold beyond which I don’t trust it to expand properly at just 250m. So my effective killing range has dropped from 700m to 250m through the change to copper bullets. It’s also got the aerodynamics of a brick.
I ran the numbers on my 280ai. That usually shoots a 160 ABLR. It’s still carrying 1000 ftlb’s and 1700 fps at 950m - way beyond the range at which you would shoot deer, but they are the numbers. Switch to a 120 TTSX launched at 3400 fps and it hits the 2400 fps barrier at just 400m. Scary stuff. Our effective ranges are going to take a hammering come the change.
The real danger is that someone who doesn’t understand the difference between copper and lead, of which there will be plenty, will just switch the 165gr lead bullet in their 308Win for a 165gr copper one. They will launch it at around the same velocity, call it 2600 fps. The bullet will perform badly and the deer will run at ranges over 100m. That’s if it get’s to the deer at all as the additional length of the 165gr copper over the usual lead bullet means his standard 12 twist barrel fails to stabilise it and it’s going sideways.
There are two major issues with copper currently.
- As BC is a factor of mass, as well as cross sectional area and form, copper bullets of the same length and design as lead bullets will always have a lower BC due to the lower density of copper. You could design a copper bullet to have the same BC as a lead bullet of the same mass, but it would be significantly longer and as a result be unlikely to stabilise in most peoples standard twist barrels. The lower BC of todays copper bullets compared to their lead equivalents means they scrub off speed and energy much more quickly, reducing the effective range.
- Reliable expansion below 2400 fps is a major design issue. If we could trust them to expand down to the 1600 fps that we trust our lead bullets to (lower in some cases) then their effective range would be extended significantly. This is going to take a major redesign of how they work. At the moment Nosler, Hornady and Barnes all have almost identical designs and all perform equally badly. GS Custom in SA have taken a different approach and reports are that they do expand much more effectively and reliably than the other manufacturers, but I have no experience of them. I will try some before long as a limited selection of designs is available through the Dutch importer.
So for copper to really replace our lead bullets like for like the manufacturers need to get their **** together and design bullets that expand reliably at 1600 fps, design longer bullets that give us an equivalent BC to our lead ones and work with the rifle manufacturers to deliver us faster twist barrels in their rifles to stabilise them.
When they achieve that none of us will have any reason to complain about a lead ban, because copper will perform as well as our old bullets. Until then there is going to be a lot of resetting of range limits and a significant change of bullet weight used if we are to continue to cull our deer humanely.
For normal stalking ranges of sub 200m, providing we are changing our bullet weights down to the smallest available in our calibre (243 to 80gr, 270 to 110gr, 30cal to 130 gr) we should all be alright. But if you want to extend those ranges you’re going to have to know what the TV is for your rifle with your bullet of choice and make yourself happy that your bullet will expand sufficiently at that speed.
