SmallCaliberCentral

So I made my first load work-up trip to the range today with RL-10x and some 32-grain Noslers for my beloved Savage 12 VL, three rounds each at 0.2 grain increments. Some of the loads proved extremely accurate but I was concerned about primer cratering. I know F205M primers have a reputation for being soft so I'd like opinions on whether my spent casings show excessive pressure.

I started seeing cratering at 25.2 grains, 1.1 grains below max. This really shocked me because I WS2-coat my varmint bullets, and the super-slick bullet is supposed to reduce chamber pressure a bit. For comparison, I got 0.2 grains over max charge with BL-C(2) before any cratering appeared, and I was using the same F205M primers and WS2-coated 32-gr Noslers.

Here's a 25.2 grain primer:



This is the primer from a 26.2 grain load, still 0.1 grains below max for a naked bullet:



At this point, bolt lift was absolutely normal. Nonetheless, I got anxious about the cratering and didn't shoot any of the still hotter "work-up" loads.

I was taking pictures of the primers for this post when I noticed something that's probably relevant. This is the primer from a 40-gr factory Hornady round I also shot today:



It shows more pronounced cratering than the 25.2-grain load (first picture above) but maybe a little less than the 26.2 grain load.

So then something else occurs to me. Is it possible there's something abnormal with my firing pin that it's roughing up primers like this? It certainly hasn't done it before.

Also, the flattening isn't that much worse at 26.2 grains than at 25.2; there certainly isn't any top-hatting. Granted, the factory load shows no significant flattening, but that's probably not a F205M primer either. So based on my shoddy pictures, would you call the pressure from the 26.2-grain load excessive?

Here's why it's important:



I doesn't touch much red and it was pinned to a white background so I didn't even see this hole when I pulled down the target. In fact, I walked away spewing profanities because I thought all three rounds had missed the paper. But my eyes nearly popped out of my head when I finally noticed.

That's a 1" grid and the hole measures 0.375 overall (-.204 = 0.171, center to center). But that's not the most amazing part. The most amazing part is that this was at 200 yards. Two - zero - zero. No, I'm not kidding. I also had 1" and 5/8" groups at 25.8 and 26.0 grains, respectively.

Granted, this group might have been pure blind luck, but I figure it's completely and utterly beyond the realm of possibility that it was all luck. There obviously has to be some amazing potential there.

Which is why I'm being so anal about this primer read.

So what's the verdict?

Hey Fred

First off, primer edges are still fairly round. No bright smears or ejector marks on the brass. Two good signs.

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.

I noticed your mixing brass. Not good for many reasons but safety is first.
JMO but Rem brass seemed a little softer in the case head area than Hornady. Its not likely but it is possible you could miss some case head pressure signs that Hornady can handle. Then proceed a little higher with Rem brass and get into trouble fast. Pick one and stick with it.

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.

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.

jo191145 wrote:Hey Fred

First off, primer edges are still fairly round. No bright smears or ejector marks on the brass. Two good signs.

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.

I noticed your mixing brass. Not good for many reasons but safety is first.
JMO but Rem brass seemed a little softer in the case head area than Hornady. Its not likely but it is possible you could miss some case head pressure signs that Hornady can handle. Then proceed a little higher with Rem brass and get into trouble fast. Pick one and stick with it.

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.

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.

Ditto on everything....and adding one item.

The length of the firing pin protrusion is too much.....

or....

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.

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.If I could post pics on this site I would show you a nice close up of four fired rounds.They ordered a UPS pick up for the gun to replace the bolt nose in their "Palama" shop.No doubt that the firing pin and the hole,didn't match.The other issue was the failure to eject.The cartridge just dropped as soon as it cleared the chamber.The return was delayed due to the first bolt nose being made for a right port gun(Shxx happens)and the hollidays.The cratering problem is 95% cured,and the ejection remains at 30%.I'll fix that myself.I believe the barrel isn't aligned parrallel with the action ,or the action is warped slightly down,as it shot 15" low at 50yds when I installed the scope, with Burris two piece bases,and 30mm Signature rings.I thought the scope's elevation knob had been turned down,but I ran it to the stops,centered it,and it shot the same place.I corrected 10" by inserting the +/- 10 inserts front and rear.Later,a friend told me he sent one back that shot 13" low at 25 yds and they rebarreled it.The floating bolt nose would take care of the minor misalignment.I sent a Email to Customer service covering all this,but have not received a reply as yet.

I'm not sure how anyone can determine that there is too much firing pin protrusion just by looking at a picture of a fairly normal primer. Pictures can be deceiving.... Using a depth gauge on the bolt face and knowing the proper protrusion for the rifle used is the only way a gun smith will know or be willing to comment on pin protrusion. Excessive pin protrusion generally causes primer perforations on even normal, low pressure loads.

In addition, if the primer and case are being pushed forward because the cases are too short and then slamming back against the bolt face, the primer would be excessively flattened in appearance as it actually backs out of the case a little bit before they both reach the bolt face due to chamber pressure. None of the primers shown exhibit excessive flatness like this problem causes.. Instead all are still rounded in appearance around the edges of the primer.

The cratering around the firing pin hole is likely just the result of a too common problem today in factory rifles. 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

I dont care how light or heavy I load my 204 all the primers do it factory loads too. I cant understand why but they arent flat so I am not really worried

Bayou City Boy wrote:I'm not sure how anyone can determine that there is too much firing pin protrusion just by looking at a picture of a fairly normal primer. Pictures can be deceiving.... Using a depth gauge on the bolt face and knowing the proper protrusion for the rifle used is the only way a gun smith will know or be willing to comment on pin protrusion. Excessive pin protrusion generally causes primer perforations on even normal, low pressure loads.

In addition, if the primer and case are being pushed forward because the cases are too short and then slamming back against the bolt face, the primer would be excessively flattened in appearance as it actually backs out of the case a little bit before they both reach the bolt face due to chamber pressure. None of the primers shown exhibit excessive flatness like this problem causes.. Instead all are still rounded in appearance around the edges of the primer.

The cratering around the firing pin hole is likely just the result of a too common problem today in factory rifles. 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

Because your powers of observation from the same picture determines that this not the problem?

As is typical BCB, he tries to pick anything that I post. Good job! Your opinion is soooo much more valuable than ANYBODY else's!!!

He asked for opinion and help. Believe he got it.

This seems to be a faily common problem on Savage rifle and Savage Arms doesn't seem to be concerned so I don't worry about it either. I have 3 Savages and had another. Of those I had one that cratered significantly more than others. I've shot several hundred rounds with no problem. I think Silverfox and others have had their firing pins bushed with good results. 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.

Hotshot
Not to nitpick but I think Remington has this (problem?) more than Savage. Remington once stated on thier website they were intentionally producing their bolt heads to create craters in small bore guns. (Its gone now)
They had supposedly determined through testing it actually lessened the chance of blanking (popped) primers.
I was pretty quick to jump on that and say phooey!!! Bad Remington Bad!!!

I may be totally wrong on that. It goes against everything we've been taught. Maybe, just maybe a little cratering at lower pressures is not as bad as we've been led to believe. I do have one Savage bolthead purchased as an aftermarket part through a vendor that craters primers at just about every load.
This summer I had it matched with a custom 11 twist 204R tube. Well I'm a little past crazy but with that tube, that bolthead and Fed 205M primers I was launching 39bk's well past the advertised Hornady velocity of their 32gn ammo, well well past

So I totally agree with you on the major point. Shoot it and enjoy.

Fred
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.

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 ).

FL sizing = Bad Advice? Sort of flys in the face of logic there Fred. Factory ammo thats FL sized well below the headspace of your rifle yet it shoots well. Your own reloads that are sized to within ???? thousandths of your chambers headspace show excellent accuracy potential.
And yet the local guru says its bad?

Done incorrectly FL sizing shortens brass life. Done correctly I've seen no evidence of that at all. The first sizing die I buy for any new caliber is a Redding FL bushing die. Since I've begun doing that its the last sizer I need to buy for that caliber.
Necksize if you like, I did for years. Made my own necksizing shoulderbump dies too. Nothing wrong with either method done correctly.

jo191145 wrote:FL sizing = Bad Advice? Sort of flys in the face of logic there Fred. Factory ammo thats FL sized well below the headspace of your rifle yet it shoots well. Your own reloads that are sized to within ???? thousandths of your chambers headspace show excellent accuracy potential.
And yet the local guru says its bad?

Done incorrectly FL sizing shortens brass life. Done correctly I've seen no evidence of that at all. The first sizing die I buy for any new caliber is a Redding FL bushing die. Since I've begun doing that its the last sizer I need to buy for that caliber.
Necksize if you like, I did for years. Made my own necksizing shoulderbump dies too. Nothing wrong with either method done correctly.

A good informative post.....

And as stated earlier, the condition of the primers in the pictures supplied do not indicate a problem with cartridge case sizing. If brass sizing was an issue, the primers would have been extremely flat from being backed out of the cartridge slightly and then primer and cartridge being slammed against the bolt face under considerable pressure even with relatively mild pressure loads.

-BCB

jo191145, that's not what I said. I said I was FL sizing on account of some bad advice, not that advice to FL size was bad. Not the same thing. And I didn't say the 'bad' advice came from the local gun guru. LGG and I were discussing a self-inflicted problem with a .243 WSSM, not this .204. His advice was to try just neck sizing for a while and see how the results compared. FWIW, COL of both rifles is limited by the magazine, so it's nothing to do with headspace directly.

Since you bring it up, once the casing is fire-formed, if it's only ever going back in the same bolt-action rifle, what's to be gained by FL sizing?

Fred_C_Dobbs wrote:....... FWIW, COL of both rifles is limited by the magazine, so it's nothing to do with headspace directly.

??????????????? LOL..!!

Fred_C_Dobbs wrote:.......Since you bring it up, once the casing is fire-formed, if it's only ever going back in the same bolt-action rifle, what's to be gained by FL sizing?

It helps to allow you to keep the case going back into the same bolt action rifle after the case has been fired a few times. At the least, bumping the case shoulder occasionally should help to keep it possible.

-BCB

Bayou City Boy wrote:

Fred_C_Dobbs wrote:....... FWIW, COL of both rifles is limited by the magazine, so it's nothing to do with headspace directly.

??????????????? LOL..!!...

Yeah, I just realized how stupid that was. I'll shut up and go sit in the corner now.

Anyway, my point was that my problem wasn't too much headspace, it was too little.