Mid-Sized Cartridge Comparison
We are often asked “what’s the difference between the 6×47 Swiss Match, the 6XC, and the 6.5×47 Lapua necked down to 6mm?” All three cartridges have 30° shoulders and fit a .308-sized boltface. However, alone among the three, the 6mm-6.5×47 has a small primer pocket and small flash hole. The 6×47 Swiss Match (made by RUAG), and the 6XC (produced by Norma), have a large primer pocket and large flash hole, just like a .308 Winchester.
Forum member DesertLefty has provided a line-up photo, with 6mmBR and .260 Rem cases provided for comparison. As you can see, the three mid-sized cases (6x47SM, 6.5×47 Lapua, and 6XC) are very similar.
The Swiss Match has the longest neck, while the 6XC enjoys the highest capacity. But performance is very similar among the three cartridges (with the 6.5×47 necked down to 6mm), and the same powders, particularly H4350, IMR 4007SSC, and N160 work well in the 6×47 SM, the 6XC, and the 6-6.5×47 Lapua. Alliant Reloder 17, slightly faster than H4350 but with a flatter (less “peaky”) burn curve, could also prove a good choice for both the 6XC and 6mm-6.5×47.
6XC vs. 6-6.5×47
Often the question is posed “Which is better, the 6XC or 6mm-6.5×47″. The correct answer seems to be “it depends”. Current batches of Norma-made 6XC brass are very good, while certain lots of 6.5×47 Lapua brass have somewhat disappointing neckwall uniformity, demanding neck-turning for best accuracy. Overall, however, the two cases (6mm-6.5×47 and 6XC) are nearly identical in performance. Some shooters believe the Lapua brass holds up better under full-power loads. On the other hand, Norma 6XC brass from DavidTubb.com is a bit less expensive than 6.5×47 brass.
The parent 6.5×47 Lapua case is rated at 63,090 psi, while the new CIP rating for the 6XC is 63,844 psi (4400 BAR). Though the 6mm-6.5×47 has slightly less powder capacity than the 6XC, max velocities with 105-108gr bullets are quite similar. However, you should not substitute loads from the 6XC directly to the 6mm-6.5×47 or vice-versa. Because of the different case capacities and primer sizes, you should work up loads separately for each cartridge.
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Tags: .243 Win, 6.5x47 Lapua, 6XC, Swiss Match
I cannot comment on the 6×47 SM, since I have never worked with that, but I have shot the 6×47 Lapua (necked down 6.5 x 47 Lapua) and the 6XC. The 6XC Norma brass I have has excellent uniformity, but I have never found it to be as hard as the Lapua 6.5×47 Brass, nor have I found it to be as hard as formed Winchester 22/250 brass (which is what I use for stiffer 6XC 600 yard loads). I don’t think any of them have any particular advantage over another in the performance dept. as they are all so close in capacity. I found N160 to be a great powder for those cartridges.
Robert Whitley
“Which is better, the 6XC or 6mm-6.5×47″. The correct answer seems to be “it depends”.
… Well darn right it does.
If you like light bullets, the traditional 6×47 Lapua is great. If you want to shoot the 115’s however, the 6×47 “chamber” isn’t the problem, it’s the small primer…
When I started working with the 6×47 Lapua, load data was still a bit hard to find, so I had no choice but to figure it out the hard way. I tested everything from IMR4198 to Reloader 19 trying to find a match for the 115 DTAC or Berger. I was frustrated because of the inconsistent results I found. Cold day hang fires and wild velocity variations from one day to the next drove me nuts, but I got it down to the nub and here’s the scoop.
The small primer might be fine for faster powders used with lighter bullets, but the small primer in the native 6.5×47 Lapua case just does not quite have what it takes to consistently light 38.5 grains of 4350 or RL17 with 115s. (I think Mr. Tubbs knows this.) Since I was already stuck with a rifle chambered for 6×47 (not 6XC) I had to find a way to use large primers, so I formed some test cases from 22-250 brass and wouldn’t you know it, problem solved. Low and consistent SDs became the norm. After that I started making 6×47 cases from 6XC brass (because they’re shorter than 22-250). Now I get to use large primers which work great with the 115s and my SDs are under 5 fps running 3000 fps.
Admittedly this process of sizing down 6XC cases is a minor pain, but the end result speaks for itself.
I know it’s from 2009… but I’ve been shooting 41-42gr of H4350 in my 6x47L and have never experienced any problems with ignition. ES of 15 or less and SD of 2-3 depending on the load, and that’s at 3220fps with 105 hybrids.
6XC or 6x47L is a non-issue, pick your poison and go for it.
People shooting an action with LR firing pin may want to go for the 6XC to be safe, or have their firing pins changed and a bushing installed in their bolt. This will indeed cause issues with ignition.