How deep are you throated? Pressures must be too high! Was it a compressed load?
I had slightly stiff bolt at 56.0 but no problems at lower loadings. However, I use CCI200 primers.
Wow! Your BTO is longer than mine! You should not have pressure issues. Not sure whats up with primer. Let's see if someone else has any ideas!
There is a little more to it than just group size. One of the "qualifiers" I use is this: Let's say the first group on the 1" target dot is about "10 O'Clock" and about 3/4" away from the target dot itself. The next group (only 0.3grs higher) is at "6 O'Clock" and 1.5" away from the target dot. Then group #3, 0.2grs higher, shoots at 8 O'Clock close to or touching the dot. The loads are, for all intents and purposes, ALL over the "map". Juxtapose this with my brand new 6mm Creedmoor rifle (shot at the same time) loads are ALL either right on the dot or in the dot on some and just touching the dot but slightly outside. ALL are virtually in the same location no matter the charge weight. That is a BIG "tell-tale" sign that this barrel does NOT like the bullet!
I have used it on previous occasions in the 6.5 x 284, along with H1000, H4831 etc.. In my opinion, the burn rate of N165 is a half shade slower than IMR 7828. This should put it optimally for the case and the 150s.. I have seen many, many times that if you are getting excessively large, very inconsistent groups, no amount of variations in powder, seating depth or anything else will "fix" something that far out of whack. When those things arise, it is either the bullet that the barrel don't like or a bad barrel! If the groups at least stayed on one side or the other of the target dot and were no larger than say 2", I would work to make it right. It is just my opinion that once the groups are this large and all over the place, it becomes an effort in futility.
ShootDots, keep us posted when you try a different bullet. I'm really sorry that it didn't work out. I know you've put forth the effort. I have well over 1100 rds down 4 different tubes which are posted here. You put me onto H1000 which works great! Thanks a bunch! Both H1000 and H4350 shoot great. Last week I shot a .570...5 shot group at 300 with .400 vertical. Over 5 groups I averaged just under 1.00 inch with the 6.5 x 284. I now have the 284 shooting like the swede at 100 fps faster. Like I said a ways back....no speed demon but fairly accurate. I'm very puzzled...several on here (wboggs, 1shot, Rardoin) just to name a few, if something hasn't changed...are doing pretty good with them. I'm sold that certain barrels at high shot count could do something to the jackets and cause failure because that can happen to any bullet if pushed to the limit. I also know that I'm preaching to the choir because you have more smarts than I ever will! But owning 4 rifles that shoot them at around 1/3 moa...one gun slightly over 1/3...and these are 8tw at that...I don't think there is a problem with the bullet so far as accuracy is concerned. I have also only had them at 1,000 a couple of times. I hope I'm not proved wrong because I've put in a lot of work to have some crazy failure.
Thank You for the kind words! I do not think there is anything wrong with the bullet whatsoever.. It is just that MY barrel apparently does not have an affinity for them! OR and there are 2 other possibilities: 1.) my barrel is bad>>>However, I think that is unlikely; and 2.) My March "High Master Model" is broken>>>also highly unlikely. Having said that, you can not rule out either of those two. I will try the Berger 140 LRBT and I think that is the most accurate 6.5 bullet made. If that doesn't shoot, SOMETHING IS AMISS! Sooner or later I will narrow it down and find the culprit.
