Re: What 6mm for a new build?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mike</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Windrift</div><div class="ubbcode-body">I want to shoot the 115 DTACS. I'm looking at .243 win, 6XC, 6x47 Lapua, 6mm Rem, 6mm Crusader. I want to push them fast, but I need reliable feeding from the AICS mags, decent barrel life, good brass selection and great accuracy. Which one has the edge?</div></div>
243 is the best.
Known performance with the 115s. (6.5mil to 1K)
Brass is good and inexpensive, plus readily available.
Hunting rounds can be easily found
Barrel life is good (3K rounds not uncommon)
Feeds from AICS mags.
Accuracy is easily .25 moa
6XC
Brass and dies from one source.
Brass is expensive
Brass has been known to be backordered frequently
Hand Loads only (or custom purchased)
Rarely can match 243 ballistics.
6x47 Lapua
Brass is expensive
Hand Load only (Lapua imports or custom)
Brass may be hard to find.
May match 243 ballistics but with higher pressure.
Barrel life may be the same as 243
6mm Remington.
Don't know about this cartridge
6mm Crusader
Fireformed Brass (right now)
Load hasn't been perfected
Barrel burner
Exceeds 243 ballistics
One source for chambering
Barrel life may be shorter than the 243
Second to the 243. </div></div>
Great review Mike!
Personally, I've shot the .243 win, 6XC, and the 6x47 Lapua. If I had to build any 6mm right now, I'd start by finding the 6x47 Lapua brass and dies on the internet. If I can buy the the 6x47 Lapua brass and dies, I'd build a rifle for that. In the past, Powder Valley (
www.powdervalleyinc.com ) has had a steady supply of Lapua brass.
The 6x47 Lapua cartridge is extremely well designed. You can indeed turn this cartridge into a barrel burner, but I settled on H4350 and Reloader 17 for an everyday "dead nuts on" accuracy load. Without even trying I had an excellent accuracy load that bucked the wind and did NOT burn barrels. the best of both worlds.
If you want maximum speed using the 6x47 Lapua brass, I have load data and reamer for that as well. You will have both higher performance as well as higher pressures, but the accuracy will remain very good.
I know Forester is making great dies for the 6x47 Lapua (I own a set). I think Sierra might be doing so as well.
Otherwise, the .243, the .243AI and the 6XC are excellent choices. My second choice after the 6x47 Lapua would be one of the .243's cartridges as brass and dies are easier to get your hands on.