I'm developing a load for my Win70 in .300WSM with the Barmes 175gr LRX. I have two loads that are shooting MOA, they are max book loads of RL19 and H4350. Velocity is book as well, low 3000 fps. The only issue is every 3-4 brass I get slight ejector cut-out marks on the brass.

I tried both powders with 0.5 and 1 grain less and the marks have dissapeared but so is the MOA accuracy. I'm now in the 1.5 to 2.0" at 100yds which is not acceptable to me.

The edge of the ejector cut-out are sharp but no burrs can be felt with a fingernail.

So my question is: book load, book velocity, nice round primers, is ejector marks every few brass always mean over pressure? Winchester brass if it makes a difference

If velocity and powder charge are book/normal it could be headspace-related. Brand new brass? I hear this fairly often with the short-mags. I would see if the same load generates ejector marks on fireformed brass with minimal resizing (slightly more sizing than crush-fit/bolt resistance level).

Just my opinion but if I'm at book max with occasional ejector marks and they disappear when I drop the charge down, then I would stay with the lower charge regardless of accuracy. If it was a headspace issue you'd still have the marks at the lower charge weight. I don't think it's a good practice to accept a load with ejector marks, even occasional ones.

Do you get the ejector marks with the last round in a 3-4 round string? You can get higher pressures with the barrel/chamber heated up.

Those are relatively fast powders for a heavy bullet in a WSM, if it were me I'd try some slower powders and see if I could get the accuracy and velocity I wanted.

I agree with smokepole; if it's a mechanical problem with a rough cut ejector hole the problem would probably still show up even at the lower charge weights. Then on top of that, if the problem disappears with lower powder charges, it's almost asuredly high pressure causing it.

Yes....was gonna say exactly that.Time for a slower powder.

Any suggestions?

One of the 4831's, I-7828, or R-22. R-17 might work too. It's well-suited to WSMs and worked best in my 7 WSM with heavy bullets.

RL17 wasn't too accurate in mine. I do have some RL22 and some H4831 that I could try. Althouh They were on the lower end of the velocity potential department from my research.

Not to put too fine a point on it, but book research will only get you so far and every rifle is different. I wish I had a dollar for every time I didn't get what "the book said" out of a particular bullet/load, or was pleasantly surprised by loads that aren't even in the book.

Sometimes it's just soft brass

Pic shows 5 loads of 4 ea. left to right bottom to top, the top brass is Remington and the bottom 3 pcs of brass are Nosler

300RUM 165 gr SGK

left - 93 gr RL25
2nd from left - 94 gr
3rd from left - 95 gr
4th from left - 96 gr
right - 97 gr



All the Nosler brass had marks and the Remington brass had none

My ejector marks aren't as bad as yours and not on all the brass. I do get similar marks with my 7mmSAUM in a Rem 700 with factory ammo, go figure?!?

Steve IIRC I used RL22 and RL25 in the 7mmWSM.I think 7828SC would work also.


Oops wrong cartridge! I used RL22 in the 300 WSM with 165's;the load was 72 gr for about 3125 from my barrel.

I have a 6.5-06AI. I started with 4831sc went to 7828, (first time trying this powder). When I noticed pressure signs, I was not really getting much for ejector marks on everything, but the AI design, I believe, gives less bolt thrust, but the pockets were shot after 2 or 3 loads with Win. brass. I switched to R-P brass which is heavier. I am using 25-06 brass for this. I reached a speed of about 3200 with a N120bt and it shot good. On a whim, I tried Hunter. I got the same speed and accuracy, but no loose pockets after several loads. I did find a slight hangfire until I used mag primers, but the pressure signs are gone. A change in powder can make quite a difference at times. It may give you some relief in your load development.

hmmm.....a couple of thoughts on this. First, different brass has not only different hardness, but different thickness, resulting in different case volume/pressure/velocity for the same load. So I'm not sure you can ascribe the ejector marks solely to the hardness of the brass, maybe there's a difference in case volume too?. This could be checked with a chronograph, did you get any velocities? If I wanted to continue shooting a load that showed ejector marks on any brand of brass I would want to confirm the pressures by measuring the velocity, at a minimum.

Also, it's pretty well established that by the time you see ejector marks on a case head, you're well above safe pressures so even if the presence of ejector marks on the softer brass and absence on the harder brass is solely due to the difference in hardness, you could still be operating at an unsafe pressure with both.

Was this batch of brass abnormally soft or something? If you're operating at a safe pressure, and getting ejector marks anyway, the brass isn't going to last long before you get loose primer pockets. If the pressure is safe and the brass deforms, I'd want my money back.

I was going to post a picture of my brass but after throwing them in thumbler for a few hours, I can only find one with still a very slight mark (can't get it to show on camera). The other must have been more of a shiny spot than a mark and now that the brass is all shiny, it's gone.

I'll stil try the RL22 and H4831sc I have and play a little more with the RL19 and H4350, better be safe than sorry.

IMR4831 and RL17 are so far the best powders that I have tried in my 300 wsm, IMR 4831 produces slightly higher velocity but RL 17 is more accurate.

RL17 wasn't that great for accuracy in mine, never got around to chrono it. H4831 comes up often with the .300WSM, I'll give it a try, I may get lucky.

I hate to be the lonely little petunia in the onion patch but if all you're getting is so little swipe that it buffs out during tumbling, since there's no stiff bolt lift and the primers don't show abuse, I don't see a problem with that load.

For one thing, primers are usually the canary in the coal mine. Some folks think the manufacturers have tweaked their cup material as our society grew more litigious so it would show symptoms of high pressure sooner so as to ward off liability suits from foolhardy reloaders. I can't swear to the truth of that but I do know if I see swipe before any significant primer mangling appears, I usually can trace it to soft brass.

That has been my experience as well. Primer starts flattening and then you start seeing ejector marks. That's why I was asking. Book load, book velocity, round primer BUT square ejector cut-out shiny spot (once in a while) and they buff right out during thumbling!? Using JB advise that velocity = pressure, I should be good but those shiny spots are concerning me.

Well, maybe I'm just cautious but I look at the same set of facts a little differently. Yes, primers normally flatten before ejector marks show up, but primers vary from brand to brand and lot to lot as far as their propensity to flatten. And actions vary too, as far as their tendency to exhibit hard bolt lift. Bottom line for me is that "conventional" pressure indicators including all three-- flattened primers, ejector marks, and hard bolt lift are unreliable enough and only show up when you're well above where you should be that if any one of 'em shows up, I'm backing off or changing powders. YMMV.

Agreed.

WSM brass is pretty tough stuff and will take a lot of abuse.But I have noticed even factory ammo from some makers will exhibit signs of pressure that is too hot in some rifles.I have seen it many times with factory stuff for the 7mm and 270WSM's. I think they want the cartridges to "look good" and live up to advertised billing.

If you are getting brass flow back into the ejector slot or hole with a given load, your load is too hot,regardless what your primer looks like.Period.

This is Handloading 101.

If "conventional" pressure indicator are not reliable, what do you use for indicator?

Unconventional ones.

Seriously though, knock yourself out. Ejector marks are OK. No big deal.

I'm not telling you what you should do, only what I would do. Big difference.


Edited to add: I didn't mean to imply that there are other indicators (other than conventional) that you should look for or use. I just used the word that way because as a lot of people smarter than me have said, they're not all that reliable. If I'm operating within "book" loads and velocities without them, and without getting loose primer pockets after a few loads, then I call it good. If I get any of the three or loose primer pockets, I back off. Even with "book" loads because every rifle is different.

Sounds like there are a fair number who don't.

Yup, I've seen the same, with Federal HE ammo for the 7 WSM, it was too hot.

+P+1+ ......or whatever

Case case head marks mean something is definitely wrong and the case is not strong enough for that load. Gas cutting is no joke, even if that's all that you're worried about. It starts with the very first case/primer failure.

Make sure your chamber is dry also. An oily chamber will cause ejector marks on a normal load a lot of times. The brass can't grab the chamber walls so it slides back under firing.

I believe I might look in another book... there are lots of them

How are the pockets holding up?

I go by primer appearance and pocket life primarily. Usually excessive extractor marks are accompanied by stiffish bolt lift as well as severely flattened primers. A faint mark on occasional loads with good primer appearance and long pocket life is hardly a thing to loose sleep over. I'd rock on.

A guy that builds pressure testing equipment once told me that brass is the weak link in CF bolt action rifles and that gross common signs of pressure appear far before any dangerous level is reached. Something to consider, not that we didn't already know brass tells.

I did.

The "conventional methods" most of us use are relative to a given rifle; meaning if there was no hard bolt lift and no ejector marks at lower charge weights and now there are, you're probably getting up there in pressures. Matching book velocity with a given powder is a good sign but the individual barrel might be generating higher pressure to get there. The primer type can make a difference too. I believe it was Mule Deer that wrote an article about the effects of different primers on both velocity and pressure. In it I think he points out that the primer type can give a big pressure increase without giving a similar increase in velocity. I've also read another good primer test on pressure/velocity on another site-I believe it was on The Rifleman's Journal which basically demonstrates the same thing.

If it was me with my rifle, I'd back off several grains and accept the fact that with that powder, I'll just have to settle for lower velocities OR go to a slower powder or possibly try another primer, starting low again. Good luck.

Seriously?? This is 180 degrees from anything I've ever read on the subject.

He's using the "best" powders from the bullet manufacturer's manual, which is always a good place to start.

"Ejector marks always bad?".. I've been loading since 18 and now I'm 64...never have pushed my stuff too much but I had a top end 264 load that I shot for years in my custom FN that exhibited no signs even with chrono and manual data but my 700 puked on it! Without a doubt individual rifles as do people have their own personalities, that's why I've never assumed one load is good enough for other rifles in the same chambering.

What I'm having a bit of a hard time to wrap my mind around is, if you're using a load that's been pressure tested by a manufacturer to produce "x" velocity safely with "y" amount of powder, shouldn't you be able to reproduce similar velocity? Different chamber, tighter barrel, etc may cause you adjust the powder charge to reach said velocity as your rifle may reach that pressure level sooner or later. If pressure = velocity, if you reach the manufacturer's velocity shouldn't you be within safe pressure level? What am I missing?

My answer is that I've hit obvious pressure signs in a few different rifles well below "book" velocities because all rifles are different. Hell, I went right past flattened primers to blowing one right out of good brass (tight pockets) below book max. Most bullet manufacturers like to be able to show high velocities with their bullets, a lot use 26" barrels for their test rifles. Some of those velocities are on the optimistic end of the spectrum.

Bottom line is, if you get obvious pressure signs and brass flow you're above the pressures the rifle is designed for.

The .300WSM is loaded hot, I've seen one that blew primers with factory loads.
That said, I have seen marks on the case head where brass wasn't resized enough, and left a mark as the bolt was turned down. If the marks are raised and brass has flowed into the ejector cut, that is a serious pressure sign and I definitely would ease up.

That mirrors what I've seen using a PressureTrace II. I first rented one from a LGS when I started loading with coated bullets (using DanZac, AKA WS2) because I was squeemish about blowing off the mfgr's load data, which is pretty much a necessity with coated bullets. I still go back to it when I switch to slick bullets in a new rifle or caliber, but the results have never changed. I always see onset of at least one and usually two of the "customary" pressure signs before either the pressure trace or my chrono gives me cause to worry.

When I reload .308 FGMM brass, if I wasn't getting high enough chamber pressure to cause swipe, I'd be worried the bullet might get stuck in the barrel.

Just a comment, and I know Weatherby's run on the hot side. All factory Weatherby ammo that I've fired in rifles that they manufactured exhibit ejector marks. With my loads in any of my other rifles, I would have backed down from similar signs.

I don't own any pressure equipment, but when the chrony says I'm approaching Weatherby book velocities, I increase charges by very small increments.

Bottom line for me. In Weatherby rifles with Weatherby ammo, an ejector mark is to be expected.

Once in my life I got heavy bolt lift with a Weatherby and one of my loads on a 100+ degree day. I immediately backed down on that one.

"Also, it's pretty well established that by the time you see ejector marks on a case head, you're well above safe pressures so even if the presence of ejector marks on the softer brass and absence on the harder brass is solely due to the difference in hardness, you could still be operating at an unsafe pressure with both."

Not sure if I agree with that or not. I have several rifles, some commercial guns and one custom and it's surprising a shell to see how many brabds of factory ammo will have ejector marks on the cases after firing. I have one Remington M700 that will crater a primer with any load run through it from a 5.0 gr. Unique gallery load with cast bullets to a full blown moose stomper. Puzzled the hell out of me until I noticed the firing pin hole had been slightly chamfered. Now I bought that rifle NIB at a store so it came that way from the factory.
My .300 Win. Mag. not only hows an ejector mark but very flat primers using Winchester factory ammo.
These days when I do a load work up, I run the loads over the chronograph, record the charge and velocity on a graph and measure the case head and expansion rings as well. Seems to work in keeping me out of trouble.
Paul B.

A good load for my 300 wsm is 64.5 grains Re-17 with a 180 Hornady Spire point. Groups running about .75 inches at 2950 fps from a Browning A-bolt with a 23 inch bbl.

Steve it's just that powder lots will vary,brass will vary, barrels will vary,throats will vary,bullet jackets will vary in hardness and resistance to engraving and bearing surface,etc, etc.

All this stuff just adds up in any individual rifle (yours or mine) to produce a slightly different results.It isn't really linear and consistent all the time.Sometimes everything works spot on (you get the same result as the pressure tested load)and other times.....you don't.

I shoot one particular load from my 270 of 130g Interlocks with Ar2213 aka H4831.

The chronoed speed is a consistent 3070fps.

When I shoot that load in Win brass, no ejector marks, no sticky lift, nothing. When I shoot it in LC brass (necked down 30-06) I get these bright marks that correspond with the ejector slot. Again, no sticky lift, no flat primers, same speed on the chrono.

I can't work that out but I have concluded - right or wrong - that it's not excess pressure causing it.