Extractor Marks?

[littlebighorn]

This is an interesting discussion for me because I shoot the 168g TTSX in my 300WSM in a Browning A-Bolt. My load is 67.5g of RL17 and I'm using Winchester brass with no ejector marks, sticky bolt or cratering. My primers are flattening, so I know I'm on the edge of my comfort zone, but I've stayed there because of good accuracy and it's a hunting rifle that I don't shoot all that often.

 

[30BR]

One reason the primers are cratered is because it was shot from a Rem action/ bolt with a sloppy firing pin hole. That can occur even with safe loads. This is the reason primer cratering is a bad sign of pressure. Primer piercing is a sign of pressure.

Ejector marks on the case head are usually a pretty good sign of excess pressure - but I'm surprised you didn't feel any excess bolt lift.

Thus the question on lube in the chamber or on the cases is a good question - as this can result in the condition above even at acceptable pressures due to thrust.

Kind of hard to tell, but the primers don't look too flattened on the edges, which I also observe when overpressure.

In summary, I'm not convinced this is excessive pressure.

I would clean the chamber with a chamber brush/swab using solvent that doesn't leave any residue. I know you said it was clean and dry, but are you sure. Also remove all lube off the cases.

If the problem still exists, then back off the charge weight

I'd also wipe down the cases with alcohol before loading.

 

[FEENIX]

I tried the same load with Winchester brass. The results were not as good as the group I posted. The velocity of the Winchester brass was 3274.33 FPS. There were very faint marks on the head stamp.

I am unsure of what the next slower velocity node is.

The COAL is what fits in the magazine of the rifle. SAAMI spec for OAL on the 300WSM is 2.86".

"You" need to find the best safe load compromise for your COAL/CBTO for your set-up, regardless of bullet, brass, or powder. YMMV.

 

[rcol317]

Based on your response concerning clean chamber and brass along with the velocity data, I would say you are over pressure.

If this is a 1-2 shot a year hunting load, then I wouldn't be worried - except if you get into hotter weather.

What happens to your accuracy and ES if you back down to 3200 fps? Another way to ask is how did this shoot when you were working up to 68gr?

I'm sure you know you are trashing your brass and my guess is the primer pockets will loosen in a few loads.

I would agree with Stammster. I have a couple hunting rifles I shoot at similar pressure but like the speed and accuracy. Not a concern for me.

 

[Plowboy85]

Ejector marks, cratered and flat primers….seems slightly over pressured as others have mentioned. If it was only the ejector marks then I would possibly lean toward soft brass as mentioned and I have experienced this myself. Seen cratered primers and nothing else as well and we know thy cause. I'll echo the others, have seen guns reach pressure before book max, especially in SAAMI chambers and not high quality framers. Also virgin brass can reach pressure sooner than fireformed as well.

 

[skipglo]

One more vote to back down. It doesn't take much.

 

[Oldtime Shooter13]

Just another thought outside the box!

What are COL and are you FL sizing or bumping shoulder back? If there is no place in the chamber for brass to expand (flow) it can create what you are experiencing. By the time you lift the bolt the brass has contacted and you have no issue with bolt lift.

Years ago I was only neck sizing on a 243 Win heavy bull barrel rifle. I don't like trimming brass so as long as they COL was less than max I chamfer only. I would go 3 or 4 loadings when I started having issues with ejector mark on brass? I was not close to max loads with this rifle. I find accuracy node and I don't care about speed, I care about accuracy. This was when I first started reloading (ages ago) and an older wiser man set me strait on neck sizing only without bumping shoulder back .001 or .002!

Today I used body dies, shoulder bump dies and still do not trim until necessary. I don't like FL sizing dies, but I don't own any semi auto rifles. I have also become a fan of collet dies.

I also learned a lesson with nice clean stainless steel wet tumbler brass. I started getting neck weld if my loads would set around for any time. I never had any signs of pressure due to neck weld, but definitely would effect ES and SD on my previous tested solid loads with my old dirty brass. Ran a test and sure enough my old dirty brass outperformed my nice shiny cleaned brass? That is why the old timers brass was always dark dingy looking? I am an old timer and just learnt this a few years ago! Now, I cannot speak to dry media tumbling, I don't shine my brass anymore other than pistol cartridges.

My Two Cents!

 

[436]

So I am looking to see what everyones thoughts are on extractor marks on the headstamp of the rifle brass. I have a load that seems to get an extractor mark on the head stamp area of the case. The bolt lifts without any pressure. The load is accurate what would you guys do? Shoot it reduce the load?

How is your primer pockets after firing your load, still tight?

 

[diamonddave2]

Alliant data shows this to be a max charge weight with a cup and core bullet I have found with Barnes you have to back off some as they pressure up sooner I would step down into a lower node

Barnes data shows it to be a tenth of a grain under max. Federal primers are softer than some. Barnes data shows Rem 9 1/2 primers and Rem cases. It does look a bit hot to me. Measure the web's to be sure.

 

[parshal]

What was the temperature when these were fired? I missed it if you already said.

What happens if you spritz a little water on the case before firing? This will simulate snow or rain.

 

[bubbaonpc]

You are there.. Or really close. Light bolt lift is a positive. I've seen "flatter" primers. (Not good). I have a rifle that leaves ejector marks, regardless of load. Always look at multiple signs for pressure.
Is this a hunting load... For cool days ? I wouldn't want to shoot that load on a hot day in Arizona. Maybe back off 1 grain, then work back up in .2 grain increments... Just to check accuracy. You may find equal or better accuracy with a lesser load... And your barrel will thank you !

 

[comen]

So I am looking to see what everyones thoughts are on extractor marks on the headstamp of the rifle brass. I have a load that seems to get an extractor mark on the head stamp area of the case. The bolt lifts without any pressure. The load is accurate what would you guys do? Shoot it reduce the load?

When I see ejector marks on the headstamps in my model 700s I refer to them as death marks. if you back down a little, and don't see them, your brass will last longer. powder charge is not the only cause of excessive pressure, but it's one of the usual culprits. If your velocity matches the max load with 2 grains under the book charge in the same length barrel I would hazard to say your rifle is at its max.
as Rob't Heinlein said.. TANSTAFL

 

[FEENIX]

as Rob't Heinlein said.. TANSTAFL

Agreed!

 

[Mike Matteson]

To me those are creators primers, and are from over pressure regardless of the ejector marks. I feel you have both ejector marks and creator primers from to hot of a load. Now I don't know what your bullet is to the lands or jump. Touching or not unknown to me. So either you can move you bullet back a little or reduce you powder load. Me I would have stopped at flat primers, and not going to creator primers, and ejector marks. I set up and load up a string of cases increasing my powder load from .2 to .5 grain increases depending on what the case normally holds to start with. Starting at the lower powder load and go up. Normally I am over the reloading manual max load by several grains before seen anything, and not like those cases and primers. I would have stopped before that. Other things you can change out your primers to Fed-210 instead of 215 primers. That should reduces the pressures some.