I thought it was time to do an article on the 6×47 Lapua rifle cartridge! When I put a new build together for a match gun last year this was the caliber I’d elected to go with after having researched a couple possibilities. Now, many months, several matches, and several hundred rounds fired later…I thought I would share with you all some thoughts and observations on this caliber. If you aren’t familiar with it, 6×47 Lapua is a wildcat chambering derived from the 6.5×47 Lapua cartridge. 6.5×47 Lapua is very similar, and nearly identical ballistics-wise, to the 260 Remington and 6.5 Creedmoor cartridges. They all share excellent ballistics and improved barrel life over the 243 Winchester. The 6×47 Lapua is essentially a 6.5×47 Lapua, made to fire 6mm, or .243 diameter, bullets at higher velocities! The extra speed, paired with high BC (ballistic coefficient) projectiles, makes for a performance powerhouse!
6×47 Lapua Cartridge
The 6×47 Lapua is currently still a wildcat caliber. The term wildcat refers to a chambering that does not have official support from institutions like SAAMI which specify chamber dimensions and pressures to be used when loading a particular cartridge. Don’t let this fool you, for a hand loader, official cartridge designations and support are not a big deal. This really affects factory loaded offerings more than hand loaders. The only difference between the 6×47 Lapua and the 6.5×47 Lapua is the neck and bore diameter of chamberings. While the 6.5×47 Lapua is an officially supported cartridge and is available as factory loaded ammunition from Lapua, the 6×47 Lapua is not.
The good news is, the only difference is the neck diameter, so producing ammunition for this chambering is easy. Likewise, it didn’t take long for folks to start chambering 6mm barrels with a reamer designed to copy the case dimensions, minus the neck. Since there isn’t a manufacturer producing brass for this cartridge, you have to do a little extra work. What I love about the 6×47 Lapua is that it only adds a single extra step to loading ammunition, and you only have to do it once!
Some other advantages? For one, the brass you use for this cartridge is made by Lapua! Lapua has a reputation for producing excellent quality brass that survives multiple firings even on higher pressure cartridges. It does tend to be pricey, at around $1 per case, but thus far I’d say the cost is well worth it. I’ve talked to fellow 6×47 Lapua shooters with over 20 firings on their Lapua cases, which is outstanding! The 6.5×47 Lapua cases used to form the cases for the 6×47 Lapua caliber also use small rifle primers. The thought here is that the smaller primer allows for a thicker brass wall around the primer which can better handle some of the pressure associated with high performance hand loads.
Necking Down 6.5×47 Lapua
The process is called necking down. Essentially you run the 6.5×47 Lapua brass, which is made for a 6.5mm, or .264 diameter, bullet through a smaller reloading die meant for the 6×47 Lapua. The die supports the entire case, but as the brass is pushed by the reloading press into the smaller die, it squeezes the neck down from 6.5mm projectile diameter to the smaller 6mm projectile diameter. It’s really as simple as running the brass through a die one time and you’ve just formed a 6×47 Lapua case out of a 6.5×47 Lapua case.
If you decide to partake in this caliber, I recommend you purchase a full length sizing die for the 6×47 Lapua chambering. You can neck the brass down using bushing dies, and this was how I initially started processing the brass for my new caliber. However, I believe this leads to somewhat inconsistent neck tension. A bushing die does not size the entire neck of the case, only a portion of it, and that can lead to consistency problems until after the first firing.
The reasons I say this causes neck tension issues are as follows: First off, I had to do a lot of resetting of my micrometer seating die when seating bullets in freshly sized cases. I believe the neck tension was varied and therefore the seating depth was not uniform and consistent. This added a lot of time to the process in the form of readjusting the seating die and measuring the rounds after seating the bullet. The second reason I say bushing dies lead to neck tension issues when used to neck down the larger brass is shown in my chronograph results. The SD and ES of bullets fired through brass that was just necked down tend to be higher and looser than the numbers I see on brass that’s already been fired and resized.
The moral of this story is simple, use a full length die to neck your brass down so you achieve higher consistency in your neck tension for the first firing. After you fire the brass and it’s molded itself to the inner dimensions of your chamber, and you’ve resized it prior to reloading the brass for a second firing, the consistency seems to go way up and offer better results on the chronograph. I will say this, another downfall of bushing dies for necking down brass can be collapsed shoulders. This results from an unsupported part of the shoulder as the press forces the brass into the smaller die giving out. I only had this happen maybe a half dozen times in about 600 cases being sized, but at $1 per case it’s still an expensive error when it occurs.
6×47 Lapua Performance
The performance of the 6×47 Lapua cartridge is just phenomenal! I was able to easily push 105gr Berger Hybrids, with a 0.547 G1 BC, to over 3100fps out of my 26 Inch 6×47 Lapua barrel produced by Criterion Barrels. The accuracy of this barrel has been just ridiculous! I can honestly, and with confidence, say that my match rifle is a quarter minute rifle. I’ve got multiple targets with groups measuring under a quarter of an inch saved and the rifle produces them very consistently. I’m not cherry picking the best group and saying, “Hey look at this,” I’m going off of the size of the groupings it produces on a regular basis. In all my testing and load development I think the worst groups I saw were around a half MOA, which is still excellent!
In terms of the rifle’s performance in matches, I’ve managed some of my best performances yet with this rifle. The 6×47 Lapua is a real performance powerhouse in a match setting. While it won’t make you a winner by itself, it does remove your ability to blame your equipment for your performance on game day. I think this has helped me strive to be a better shooter. It’s easy to make excuses for how you’re shooting when you think to yourself that your equipment is holding you back. It would be like driving a bone stock Mustang in a NASCAR race…if you don’t win, it’s easy to point your finger at the car. On the other hand, if you show up on race day with a fully tricked out and tuned vehicle, the only performance gap there could possibly be…is the driver!
6×47 Lapua Ballistics
I wanted to just throw up some ballistics results from the fantastic, and totally free, JBM Ballistics calculator to illustrate some of the performance numbers that are achievable. These are all real world numbers I’ve met, and exceeded, with my own handloads. So nothing about the muzzle velocities are hypothetical or “best case scenario”…this is all real world performance. I think the numbers will likely speak for themselves. Pay particular attention to the drop, and windage, at ranges around 700 yards, which is fairly common in matches. You can also look at the 1000 yard results. Even though most people don’t shoot to that distance very often, it can be useful when comparing performance of different calibers. I ran this with numbers for a fairly common 308 load, my 6.5 Creedmoor handload, and what I’m using in my 6×47 Lapua. Behold!
|Calculated Table – 308 Winchester – 175gr Sierra HPBT @ 2650fps|
Nothing wrong with the good old 308 Winchester, it’s been getting the job done for a long time! However, better options exist today…
|Calculated Table – 6.5 Creedmoor – 123gr Lapua Scenar @ 29295fps|
The 6.5 Creedmoor is obviously a higher performing cartridge. At 1000yds, it’s over 100 inches flatter and 30+ less wind drift!
|Calculated Table – 6×47 Lapua – Berger 105gr Hybrid @ 3100fps|
The 6×47 Lapua is higher horsepower still, shaving around 50 more inches off the drop, and another 15+ off drift at 1000 yards. Keep in mind, that’s at the outer edge of the performance envelope. I think the 700 yard performance is more relevant. While the differences are smaller, they’re still significant!
The 6×47 Lapua is an awesome caliber! The Berger Hybrid bullets are not seating depth sensitive and have a high ballistic coefficient in comparison to offerings from other bullet manufacturers. Velocities in excess of 3000fps or even 3100fps are common with this caliber and that makes for a very flat shooting cartridge. A flatter trajectory increases your odds of a hit, on an unknown distance target, due to the shallow trajectory that doesn’t dive in at the target at a high angle. The smaller .243 caliber bullets produce less recoil making it easier to spot the effects of your shots, even when in compromised shooting positions and under stress!
Additionally, the 6×47 Lapua tends to have a longer usable barrel life than a 243 Winchester. I’ve seen many people reporting between 1800-2000+ rounds before the barrel performance starts to taper off! I can’t speak to that yet as I’ve not put a full 2000 rounds through my barrel, however, I expect to be nearing or exceeding that number before the end of next season! At which point I’ll have a better feel for the life of the barrel under a high performance set of demands. I have seen only about 0.002″ of throat erosion in over 600 rounds. I may seat the bullets slightly longer (chasing the lands!) when that number gets to be around 0.005″ to keep the bullets jumping the same distance and to retain the awesome accuracy of this hand load! If you have questions or comments, I’d love to hear them below!