I’ve found a lot of people finding my site when searching for differences between the 338 winchester magnum and the 338 Lapua Magnum and I wasn’t too pleased with some of the other results, so I thought I’d lay out all the differences in one spot.
The primary difference between the 338 Win mag and the Lapua is in performance. With 250 grain bullets, the Win Mag is pushing 2650, while the Lapua is just short of 3000 fps. That’s splitting hairs for on-game performance, but makes a pretty big difference for long range shooting. Wind drift and drop are both less critical with that extra speed. Alternatively, you can run 300 grain bullets in the Lapua for amazing BC’s and better 1000+ yard performance. With 300 grain bullets, the win mag throws them at ~2300 fps, while the Lapua sends them downrange at 2550 – 2600 fps. The performance comes at a price though, both of these rifles will burn through a barrel in relatively few shots, with the Lapua doing it much faster.
One of the interesting differences between these two is the types of brass available. Both are expensive, but Lapua brass for the 338 Lapua mag is right up there; $3 each new or $1-$2 for once fired brass. The quality is there though, that Lapua brass lasts an incredibly long time and is very uniform. The Winchester branded 338 Winchester Magnum brass is no steal anyways at $1/each, because it’s not like you’re getting tremendous quality for the premium price. The Lapua’s 338 brass will last multiple times longer than Winchester branded brass.
So, the 338 Lapua is faster, a bit more accurate and better. So why isn’t it more popular? Well, one big reason is that it needs a beefier rifle than standard. A much bigger barrel, a muzzle brake, potentially modifications to the magazine, bolt, etc. Some rifles adapt well, others not so much. That translates to more expensive rifles. Most rifles chambered in 338 Lapua mag are in the $2000 range, but there are a few in the $1000-$2000. To be fair, they’re usually really nice, accurate rifles but inexpensive versions simply do not exist. In comparison, there is much better selection and availability of 338 Win Mag rifles. It’s straightforward to adapt a normal bolt action rifle to 338 Win Mag, so there are lots of them out there. There are many 338 win mag rifles in the $500-$1000 range.
When it comes down to hunting, the answer is obvious; unless you’re doing your hunting at 1000 yards, the 338 Win mag is a better choice. More inexpensive ammo, more standard rifles, no muzzlebrake required, and still enough energy to kill anything you need to. The 338 Lapua is a better round, but the availability and cost of both the rifles and ammo are too high.