Suffice to say, the popularity of the 6BR, 6.5x47L, and 6mm version of the L, seems to indicate little problems w/ignition.
I Do believe if you wanted ABSOLUTE reliability in worst case - i.e. very cold temps, the larger primer ctg's may be theoretically and perhaps in real world, better.
IF only the gun mfg's would make 8" ROT 243s, it would question the build of say a 6BR, 6x47L, etc. as THEN you could shoot ALL wt. bullets, and if accurate, it would be cheaper burning up a factory tube. Brass stretch, life, and accuracy may be enhanced w/OTHER 6mms.
I am like Clark98 - and have LOVED many 6BRs I have owned.
70s at 3400+, 95s at 3k, and 105 at 2850 have done all I need in a 6mm (inc. deer to 400 yds), but that is just me.......and case life, powder consumption, bbl life, and accuracy are w/o peer IMHO vs. the larger rounds.
What might be a good plan, get a good shooting 243, wear it out, then bbl in 6BR, and half into it's life, say 2k rounds, re-chamber for a larger round cleaning up the throat and get the last use out of that chosen round.
Then one might get a 'sampling' of 3 rounds to compare.
I have enjoyed 243s, but never found a 6BR lacking and usually found them preferable for MY type of shooting.
No matter which 6 you choose, odds are you will enjoy it during it's productive bbl life
