Sorry so long to get back to this but I've had a busy weekend, plus I needed to do some more research before revisiting this.
jo191145 wrote:Hey Fred
First off, primer edges are still fairly round. No bright smears or ejector marks on the brass. Two good signs....
My thinking as well. Normal bolt lift was "good sign" #3.
...In pic #1. What caused those shear marks on the edge of the primer? looks like you tried to pry it out with a screwdriver
Fix that issue....
That's a photographic artifact, a glitch sometimes demonstrated by digital cameras photographing a bright object. Unfortunately, I didn't notice it until after I'd decapped all those rounds. A lot of UFO myths have been started by that same phenomenon.
...I noticed your mixing brass. Not good for many reasons but safety is first....
I segregate by weight and brand. With what I had on hand, I ran out of Hornady brass at that particular weight. Rather than switch to Hornady brass of a different weight, I filled in with Remington brass of that same weight. Each 3-bullet group
was all of the same brand
and the same weight. These R-Ps cases all were saved from factory loads I'd shot, but I don't shoot factory ammo any more; once they're shot out, I'll be all Hornady.
...Once again JMO. Don't mix naked bullet ammo with WS2. Especially ones using different powders. Don't mix fouling from different powders at all. Its not dangerous but during load development it'll have you chasing your tail....
I've not shot a naked bullet in this rifle since I started coating, and I clean after each range session. And except for sessions when I shot factory ammunition, I've been strictly one powder.
...Judging by your primers I'd say you have either a large firing pin hole. A firing pin cut to the wrong radius. Or possibly not enough firing pin protrusion. Or a mixture of those issues.
What strikes me as odd is that I didn't see this on any of my BL-C(2) loads until I was 0.2 gr over max.
acloco wrote:...You are resizing the brass too much (bumping the shoulder back to far) and the brass is being rattled a touch. Firing pin hits primer, ignites load & pushes should to front of chamber, powder starts to ignite, expanding case, then shove the brass back against the bolt/firing pin.
Acting on bad advice, I was full-length resizing each reload. I've had an audience this morning with the local gun guru and he set me straight; I'll be neck-sizing only (whenever possible) from now on out.
Joe O wrote:I wen't through this primer cratering ordeal,with a new Savage LRPV,which,out of the box,untuned,shot .333 groups with factory ammo.I had three issues,and dealt with customer service with Emails (pictures of primer cratering on Hornady factory ammo)It did the same on all primers.It wasn't a pressure issue....
Joe O, even though I mentioned it in the OP, I didn't give the the "firing pin problem" idea much credibility. But based on what you're telling me, I'll contact Savage customer support. What can it hurt?
Bayou City Boy wrote:...The firing pin hole is larger than the firing pin and this is allowing brass to flow into the gap. Having the firing pin hole bushed and the pin turned to match will solve that issue if it bothers you. Greg Tannel does this for a very reasonable price with very quick turn around...
-BCB
Much obliged, BCB. If what Savage tells me doesn't give me a warm fuzzy (and maybe even if it does), I'll contact Mr. Tannel. Can you tell me what city he's in?
Hotshot wrote:...There was a post on here a couple years ago that showed how to adjust the firing pin protrusion of a Savage bolt, yes they are adjustable. NO, I do not know how to find that post! The results were mixed. Some reported good results and others some to no help. I have a friend that also gets significant cratering and many hundred rounds have resulted in no problems(he doesn't even use thick cup primers). I always use BR-4 primers. In my past experience big craters are accompanied by increasingly flatter primers as pressure increases, then primer pockets loosen. If I were you, I'd ignore the craters on that rifle and watch for the other signs of pressure to determine a problem. When you have a rifle- load combo performing like yours is, just shoot and enjoy.
I'm pretty good at Internet research so I'll see if I can find the details on how to adjust the firing pin. Thanks for the heads-up. I would have preferred CCIs but the Federals were the only SR match/benchrest primers I've been able to find. And thanks for the advice.
jo191145 wrote:...Pressure signs on cratered primers such as yours. Next you'll see flattened edges. I expect to see some of that. Its a racehorse 204R running at pressure not a 25-20 Winchester. Next you'll notice the firing pin indentation begin to look just a hair shallower than normal. Thats where you should stop. If that indentation ever starts to look square/flat on the bottom your way over pressure. The step after that is a small pin sticking out of the primer indentation which is no longer an indentation. You don't ever want to see that. trust me.
Just keep a closer eye than normal. My quess is you'll be just fine as is.
I kept a primer from my load work-up with BL-C(2) that was slightly top-hatted as a training aid/reminder, but it was 0.3 grains over naked bullet published max. Thanks for the clues; I'll definitely keep an eye on them.
I'm mooching off a buddy who has QuickLoad on his PC. Before I made the OP, he/I didn't have bullet data for the 32-grain Nosler bullet I'm shooting but this weekend I updated his software. That's one of the reasons I've been so long coming back to this thread. However, I'm not sure the info I'm getting from QuickLoad is credible.
Max RL-10X (naked bullet) load with this bullet is 26.3 gr, and my magic load was 0.1 gr under that. However, even considering the coated bullet, QL predicts a chamber pressure of 62,011 psi with that charge, almost 3000 psi over the SAAMI max. But it also predicts an MV of 4131 fps, which is within 26 fps of one of the forum user's loads shown among this forum's favorite loads, so
that much of it seems accurate/realistic. It also predicts 54,555 psi for the 25.3-gr load, ~4000 psi below the SAAMI max, yet my primers are still cratered. Puzzling.
Coincidentally, my most accurate load with BL-C(2) also was 0.1 gr below naked bullet max, 30.6 gr. QL predicts a pressure of 61,885 psi with that charge, also well over the SAAMI max, so at least it's consistent at over-estimating the pressure. And
that load shows
NO pressure signs, not even the slightest hint of cratering.
And that's what strikes me as odd, and why I even bothered to mention the QL data.
Another point from QL was the pressure curves. Before I looked it up in QL, I thought maybe a steeper pressure curve would account for cratering at a smaller charge. It says BL-C(2) generates max pressure at .368 ms but RL-10X maxes at .375 ms. So either I'm mistaken about the affects of a steeper pressure curve or QL's pressure curves are as bogus as their predicted max pressures.
In any case, I thank you all for your advice. I take comfort that no one thinks I'm about to blow up my rifle. I visited with my gun guru this morning. He doesn't have the specialized .204 knowledge assembled here but, after comparing to the factory round's cratering, he also was of the opinion that I wasn't too far over the edge.
And forgive the broken record but even with factory ammunition, this is an astonishingly accurate rifle. I take no credit for it; when you throw a 12-pound rifle with a 25-power scope onto a 20-pound sandbag, all that's left for the shooter to contribute is to not screw up the trigger pull. I mean, 0.082 MoA??!!?? And at 200 yards, in a light breeze, and with a 32-gr bullet? Are you kidding me?? It won't surprise me in the least if I never again approach that level of accuracy but, thanks to a all your responses, I fully intend to test that load some more (but I
will stop mixing brass
).
