you guys have me thinking. Which of these will feed reiliably in a rem SA? </div></div>
6XC brass is cheaper but the 6x47 Lapua will drive the 105 faster.
</div></div>
Because the case design at the web is stronger than the other 6mm's mentioned. Rated for 64,000 PSI coupled with a small primer pocket and small flash hole. There's a lot of extra brass at the bottom part of the case.
</div></div>
6XC has same rating and the chamber design has more to do with case failure (which is what I think you are driving at) than nominal differences in case design. Everybody's mileage will vary but I would rather have more case capacity than ride the ragged edge of case failure/bullet failure on a hot day at a match. Running hot loads with long pills will also torch the lands at the case mouth a lot sooner. </div></div>
I looked it up and the Tubb 6XC does have close to 64,000 PSI rating. I didn't realize that. Good to know. However I found this post about 6XC brass interesting.
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2739834
I will mention that the 6.5x47L case is the strongest case I've ever shot. It's been 5 years now since I bought them and I don't anticipate having to buy cases for many more years.
My theory is that chamber design "within reason" has little to do with case life. I think the metallurgy in the case has more to do with the cases ability to handle pressure, along with the attributes I've already mentioned. Next would be how much the case is resized every time. If a case is only sized a few .001's to fit in it's chamber (Edit) "match dies and match chamber" vs being sized .010 to fit,(Edit) "I meant a biggish chamber and smallish dies over sizing the brass", the latter case will fail sooner. Back to my 6.5-284 analogy... It's the best example I can think of to make my point but not the only example I've had the displeasure to experience.
I learned my lesson about throat life after the last 6x47L barrel went south at 1500 rounds. Striving for that extra fps wasn't worth the hassle. I've been plenty competitive shooting long range at 3025 fps with 115's, which is a medium load in my rifle. My hat is off to anyone who can guess/read .1 mil in the wind, which is that extra 100 fps. I know I can't.
All that being said. If I had more expendable income I'd be looking real hard at the 6mm Crusader, 3300 fps =.2 mil advantage in the wind is notable. The problem is that most of the tactical matches I've been to have a 3100 fps velocity cap. One could always load it lighter if they wanted and preserve some barrel life but Nah, I'll stick with what I got.
