Ejector marks: How much is a deal breaker?

[OkieMike]

Been doing some load development with .308 lately... Lapua brass, CCI BR2, and 177 SMK. Powders used... IMR 4064 & 4895, and Varget.

I've really moved away from flattened primers as an indicator of pressure... At least if that's the only sign I'm seeing. I often see a bit of flattening starting at bottom end loads.

So how "bad" does an ejector mark have to be before you stop?

I've taken to marking the bases of brass with Sharpie for the specific purpose of being able to detect ejector marks. You hold the brass up and as the light hits it you can see where the ejector was...

But none of these stamped "into" the brass. No smearing/swiping. No burrs. Just the very lightest circular marking where the ejector made contact... It really didn't even smear the Sharpie off. And you can see them starting at just a charge or two above minimum.

I've always just avoided a combination of flat/cratered primers, ejector indents/burrs, etc... hard bolt lift was always the "nearing death" indicator.

How heavy is too heavy for ejector marks in your opinion?

Mike

 

[waveslayer]

Pics?

 

[OkieMike]

Pics?

I tried. But trying to get anything discernible is proving to be a challenge.

I'll try again... Give me a few.

Mike

 

[OkieMike]

This picture came out better, but still lousy.

Here is 44.2 gr IMR 4895... Mark is at 12 O'clock. The light makes it look more pronounced than it actually is. This one actually had some of the Sharpie rubbed off which is the shiny spot you see near the last "A" in Lapua. Just to the right of the shiny spot you can see where the ejector "kissed" the brass but didn't remove any Sharpie.

Mike

 

[hlee]

I’m no expert, but if you have to sharpie the case to detect it- and there are no other signs of pressure- I’d say you’re chasing ghosts.

 

[Huskydriver]

That's the snipers hide starting zone... Usually about 1gr over book Max...

I think you can do better gotta be at least another grain in there maybe 2

 

[OkieMike]

Here's another... IMR 4064, Max charge where I quit loading @ 43.5 gr.

It's about 11:00 between the L and .3

The light scratch you see in the lower left of the ejector mark is where I ran a piece of metal over it to see if I could feel any type of bump... Didn't feel one.

Mike

 

[OkieMike]

I’m no expert, but if you have to sharpie the case to detect it- and there are no other signs of pressure- I’d say you’re chasing ghosts.

You're probably right. I've become real cautious about all this lately... Not sure why either.

Part of it may be that my near sight has gotten worse over the last few years. Have to take off my damn glasses to read a pill bottle... Or check brass. The Sharpie helps highlight anything that would stand out to the younger among us.

Mike

 

[Huskydriver]

Have you ran the difference and wind and drop at book Max vs book starting speeds?

 

[OkieMike]

Have you ran the difference and wind and drop at book Max vs book starting speeds?

Hell, none of those are even book max. I didn't even chrono them... Wanted to see where I'd run into pressure first.

I think I'm overthinking this.

Mike

 

[Huskydriver]

The only reason I ask is usually you are less then a couple clicks difference... Dialing clicks is free... Your face and brass life are not

 

[OkieMike]

The only reason I ask is usually you are less then a couple clicks difference... Dialing clicks is free... Your face and brass life are not

Good point.

Mike

 

[1911hombre]

You're probably right. I've become real cautious about all this lately... Not sure why either.

Part of it may be that my near sight has gotten worse over the last few years. Have to take off my damn glasses to read a pill bottle... Or check brass. The Sharpie helps highlight anything that would stand out to the younger among us.

Mike

Bifocals. Before you blow all of us up.

 

[OkieMike]

Bifocals. Before you blow all of us up.

I've got bifocals.

Mike

 

[Doom]

Been doing some load development with .308 lately... Lapua brass, CCI BR2, and 177 SMK. Powders used... IMR 4064 & 4895, and Varget.

I've really moved away from flattened primers as an indicator of pressure... At least if that's the only sign I'm seeing. I often see a bit of flattening starting at bottom end loads.

So how "bad" does an ejector mark have to be before you stop?

I've taken to marking the bases of brass with Sharpie for the specific purpose of being able to detect ejector marks. You hold the brass up and as the light hits it you can see where the ejector was...

But none of these stamped "into" the brass. No smearing/swiping. No burrs. Just the very lightest circular marking where the ejector made contact... It really didn't even smear the Sharpie off. And you can see them starting at just a charge or two above minimum.

I've always just avoided a combination of flat/cratered primers, ejector indents/burrs, etc... hard bolt lift was always the "nearing death" indicator.

How heavy is too heavy for ejector marks in your opinion?

Mike

I think you are misunderstanding what pressure signs mean. Each component of a rifle cartridge has a pressure limit where it will fail. Be it the primer or the case. It isn't so much about the barrel or action failing. When you begin to see the brass flow such as an ejector mark or primer flow/ejector marks you are seeing signs that the brass is beginning to exceed its pressure retaining capability. Trying to read anything more into one sample is fruitless because the next piece may show more or less or may fail depending on the myriad variables that affect shot pressure. In the case of ejector marks on the head of the brass this indication means the base of the case has yielded and dimensions have changed. This has taken life (reloads) out of the brass.

As for primers deformation is a sign that the primer is yielding but being a one and done piece this isn't a problem when it deforms. What is an issue is when it deforms enough to structurally fail and allow gasses to escape the chamber. Then the primer shows major deformation, you are operating in the yielded region of the material and the higher the deformation the closer to failure the primer is operating.

Only you can judge whether you are willing to operate with your loads in these zones. For instance I have a 308 that craters primers at any load level. Because I know the rifle craters primers I don't use cratering as a sign of over pressure. But I can use excess flattening as an indication.

 

[RegionRat]

Sometimes the headspace can set up a situation that mimics pressure signs on brass.

When a ejector is pushing the case forward and the case has been sized very short, it sits with a larger than typical gap between the case head and the bolt face. When the cycle begins, the primer cup can move backward in the pocket till it runs into the bolt face and then the case expansion catches up with the case finally moving back.

This action can both leave an imprint of the ejector hole on the brass as well as allow a primer to become mushroomed, but without "high" pressure.

So, we should also keep an eye on factory loads and reloads for looser than normal headspace. A rougher or sharper than normal finish on the edges of an ejector hole can also mimic pressure signs just like the above mention of how some firing pins and firing pin holes can make cratering that gives a false impression of pressure.

Beginners should try to stick with known good recipes and have an idea of what their velocity should be and what the corresponding pressure should be. They should always avoid the MAX and MIN edges of the recipes until they have gained experience and even then only go there with all eyes open.

The OPs load recipes were not alarming and it is good that he noticed the marks and asked questions. The use of a chronograph is helpful when these questions come up. If the published pressure and velocity are put into perspective, the dialog is more focused when these marks are observed.

 

[ma smith]

I'm no reloading expert, but there's some kind of problem when you are not actually reading what the cartridge is telling you...

I'd 100% delete that sharpie, and use "clean" brass. I'd use better, higher-resolution imagery. Take pics under proper lighting conditions. If you are taking pics in direct bulb-light, you need a diffuser to cut the glare. EG, put a piece of white paper over the bulb to act as the diffuser. Next, steady the camera since you'll have less light with the diffuser...eg Rest the camera on a book or ammo box etc so its not shaking.

Get 100% crstal clear image at 100% resolution, and look at them on your computer...

 

[Doom]

Hell, none of those are even book max. I didn't even chrono them... Wanted to see where I'd run into pressure first.

I think I'm overthinking this.

Mike

If you are looking at Hodgdon data it is in Winchester brass which has about about 1.5gn H2O less capacity (2.7%). It matters.

 

[Sheldon N]

Here's another... IMR 4064, Max charge where I quit loading @ 43.5 gr.

For what it's worth, Quickload says both the loads referenced above are 65k+ PSI. (43.5 4064, 44.2 4895)

For pressure signs I like to use bolt lift first. As soon as there is any additional effort in extracting a fired case beyond what it feels like lifting the bolt on an empty chamber that's about good enough for me. I find that will come in far before getting flat primers or ejector marks.

Not really a safety thing, I just like a gun that runs smooth.

 

[Potsy]

I’ve come to the conclusion that rough bolt faces and brass running around all loosey-goosey in a chamber (read “new”) will print up bases as much as anything. Softer brass doesn’t help.

I have a bunch of Federal .25-06 brass running around forever (deer rifle doesn’t get shot much). I’d get ejector marks on it when I fired it loaded at the factory.

I’ve loaded stuff plenty warm over the last 25 years. Really only been scared about 3 times. The last one was the worst, and wasn’t even trying for speed (pretty sure I had some H-Universal hang up in the uni-flow).

I’ve come to the conclusion that your best friends are loading manual and a chronograph. You can sub components, but if you’re running fast, there’s a reason, and it probably ain’t “magic” powder or “efficient” case design. Took me a looong time to admit that.

 

[spife7980]

Id ask how far do you have to load down until it doesnt give you marks or bolt lift etc.
If its a good ways then you know you were clearly overpressure.
I bet the real world performance wont be noticeably worse either at sane pressure levels. As Sheldon said, its nice having a gun that works nice and easy.

 

[jLorenzo]

Shoot some factory ammo and see how the brass looks

 

[vh20]

Shoot some factory ammo and see how the brass looks

I bet it looks the same. I see ejector “stamps” on lots of factory loads in multiple rifles/cartridges. I start paying attention when I get “swipes”, or increased bolt lift.

 

[918v]

The 44gr of IMR4895 load is way over max. Come down a couple grains.

 

[hafejd30]

I’ve run a lot of 308’s pushing 175 smk or 178 ELDX. All on IMR 4064. I have found case capacity/accuracy etc shine around 42.0-42.5. That’s kind of the magic area for that combo. Usually if a 308 is going to shoot that’s a combo that does well.

Lapua brass and CCI 200 primers

I still get ejector marks like shown in your 4064 pic on mine. My brass looks basically the same. Running an AI AT rifle

It’s a 308 so realistically the goals are

 

[RegionRat]

I don't know how many versions of the load manuals are online any more, but the Hodgdon site shows the brands they market, so that includes the IMR stuff like 4895 and 4064
I don't know if the OPs rig is close to pressure or not, but the 44 grain load with a 175 SMK is included so I'll post it here for reference. If the OP's pressure is running around 58 to 60 ksi, he should be okay. One way to judge if his rig is following the script is to check the velocity and see if it makes sense.

 

[918v]

Hodgdon’s data is based on a commercial Winchester 308 case that has way more capacity than Lapua.

 

[RegionRat]

Agree, very important point.

The difference between a case with a 58 grain capacity compared to a 54 grain capacity can account for roughly 10 ksi in a 308 near max.

The thing is, you can also catch that with the velocity. If your speed is 100 fps faster than it should be, you are also pushing pressure. That can leave ejector marks even if the bolt opens easy.
Here is a rough GRT model that shows your point.

44 grains IMR 4895, 175 SMK
If a fireformed WIN case is 58 grains, the pressure is 55.2 KSI and MV is 2667 fps
If a fireformed Lapua case is 54 grains, the pressure is 66.6 KSI and the MV is 2763 fps

 

[JerkyFreak]

What should also be concerning is the cratering around the firing pin indentation. Either high pressure or overlarge firing pin hole. If it is present in previous safe loads it is probably nothing.

I know of multiple indications of high pressure; sticky bolt-lift, ejector marks/swipes, primer cratering, flattened primers, blown primers. If more than one is present I normally assume high pressure until proven wrong.

 

[jLorenzo]

I think a burr from the ejector is something to worry about, a slight mark that is mostly smooth less so.

 

[thexman]

Not sure if this the case, I had similar issue with mine last year, found out it is pressure sign and I got loose primer pocket after about 5 firings for about 8% of the batch.

What's your barrel length and MV using Varget?

 

[OkieMike]

Thanks for all the replies.

A few things I failed to mention in my original post. And to address some questions/concerns others brought up:

• This is the wife's Bergara B14 HMR Wilderness... She had a melanoma cut off her shoulder a while back and hasn't been able to shoot... So I was playing around with different bullets/loads... Just to see what I could cook up.

• This gun craters primers. Even factory loads from Hornady/Federal 168 GMM. I figure there's some slop around the pin hole.

• For those who asked/wondered: 20" barrel.

• COAL for these was over book length. It was 2.850"

If you align the junction of the boat tail/bearing surface of the bullet with the shoulder/neck junction of the brass, the 177's run about 2.875" which won't fit in the magazine... So I backed off to 2.850" which just fit the mag and is 088" off the lands according to the Hornady comparator. I still had a few where the tips hung up on the feed ramp at 2.850"... So I'm going to back off another .020 or more.

Not only am I going to settle in around 2.82 to 2.83, I'm going to test between 42.0 to 43.0 gr of IMR 4064. The 175's usually shot good there usually around 2550 fps... And I have more 4064 than anything else.

I only have the one pound of 4895. Never messed with it much... But I have 2 boxes of Nosler .308 brass and some 150 grain bullets that showed a bit of promise... So I will likely save the 4895 and test it with those. If it pans out I may pick up some more... Maybe. I never would have figured Varget would ever be cheaper than 4064/4895... But here we are.

Varget may also be tried since it's "cheaper" but I have enough 4064 on hand to last quite a while.

Mike

 

[RegionRat]

Got a fired case internal volume by water weight number for your brass?

 

[OkieMike]

Got a fired case internal volume by water weight number for your brass?

5 cases filled to perfectly level or just a slight meniscus averaged 56.44 gr of water.

56.54 was the high, 56.26 the lowest.

Mike

 

[OkieMike]

If you're running it through QL/GRT...

OAL of a 177 is 1.32" with a boat tail length of .18"

Mike

 

[FuhQ]

That's the snipers hide starting zone... Usually about 1gr over book Max...

I think you can do better gotta be at least another grain in there maybe 2

 

[FuhQ]

I've noticed that with a lot of virgin brass, on the first firing, I will get some slight ejector swipes, even much lower than max pressure, but that's from the brass flowing to fill up the chamber as it fireforms to it. On virgin brass (and even sometimes on heavily FL-sized brass), if I see a swipe, I don't put TOO much sweat into it, but I do take notice and mental notes to watch for more signs in the future.

That said, I do tend to push mine pretty hard...But I understand and accept all the risks involved, as I've been doing this a long time.

 

[Doom]

!75 SMK and IMR4064 is going to be happy at roughly 42 gr in Lapua brass and will be about 2500 fps in a 20" barrel. That was the FGMM load 10years ago and pretty much the M118SB LR that Federal loaded as MK 316 Mod 0 in Federal Brass.

 

[RegionRat]

PM sent

 

[OkieMike]

!75 SMK and IMR4064 is going to be happy at roughly 42 gr in Lapua brass and will be about 2500 fps in a 20" barrel. That was the FGMM load 10years ago and pretty much the M118SB LR that Federal loaded as MK 316 Mod 0 in Federal Brass.

I was running 175's over 42.5 gr of 4064 forever... Average speed was 2530-2550 neighborhood. Groups were sub MOA. No complaints.

Bought 2 boxes of Winchester M118 LR (brown cardboard box) a while back. Shot good groups. Average velocity was 2600. SD was what you'd expect from factory ammo. I knew there was no way to reproduce that velocity without pushing hard though. Didn't buy more because the place I bought it from was asking $40/box... Did find more online for $27/box so may give it another whirl.

Anyway...

My main question was "how much" of an ejector mark with the absence of other obvious pressure signs was a "nope" for other shooters?

We all know what bad ejector marks look like... But if you have to break out a magnifying glass and hold the case just right for the light to show one... Is that really an ejector mark? It's like the difference between sticking your finger an inch into wet concrete vs. leaving a finger smudge on clean glass.

That was the main point.

Mike