.300 RUM seems to give ejector marks very easily ?

pc

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It seems to me the .300 RUM gives ejector marks quite easily on brass even with loads that are a under max.....................you can get ejector marks but no sticky bolt lift, have others found this ??
 
So do not worry abut slight ejector marks wit ha load of 92 gr of Retumbo behind the 200 gr Accubond folks..............................I have no bolt stickiness whatsoever ??
 
Just yestarday I put about 35 rnds through 270x300RUM, doing some load developement. Most loads started with 95 to 97gr and worked up to between 103 and 109gr, every other shot left some kind of ejector mark on it. But when you start to see the mark getting real shiny. Beware, the brass is starting to flow and pressure is getting high. If I remember correctly cartridge brass starts to flow @73k psi. That is if my memmory serves me correctly. Just the same SAAMI standards are set @63 or 65K psi as max. For most newer cartridges.
 
TX thanks for that I will check those marks !! interesting to here that you have ejector marks on all you loads................seems to be an irritating round, if I got to loads with no ejector marks I am around max loads for the .300 winnie !!
 
Hey txhunter

Where abouts are you shooting, and what are the ranges?

I will be doing some developement soon myself and it's more fun when you got company. I am just a tad north in the H town area. Shoot em a e-mail if you want to hit the range sometime after the first of the year. From now till then I am pretty much tied up on the weekend. BTW you ever hit the surf down in that area? Might be able to work something out there as well.
 
Re: Hey txhunter

I think it's common to see ejector marks if you might have a generous amount of headspace. I just started loading for this caliber and boy the brass seems pretty heavy duty.
Are you still seing marks at moderate loads with good tight headspace....say under .002"??
 
Re: Hey txhunter

The brass I'm using is at least once fired, so brass is fireformed to my chamber. I don't resize. Don't need to, tight neck chamber. I just decap, reprime, charge and seat bullet. Now when I say ejector marks I mean It is more of a ghost image of the ejector pin hole. Only when there is to much pressure does the brass flow back into the hole, then shear off when lifting the bolt, Hence leaving an nice shiny circle on the case head.
 
Re: Hey txhunter

I've also seen those "ghost images" with light loads of Retumbo. I figured some of it might be caused by a rough ejector and have since replaced the ejector--but haven't worked up from a light load since to see if that helped.

Once I determined these weren't "real" ejector marks and added more powder they went away. Then once I'd get to real high pressure loads ejector marks would re-appear but they'd be really shiny, "wiped" looking ones. Those are what I call "real" ejector marks and back down from any load that shows them. In my rifle (A-Bolt), even when these marks show up bolt lift is still as light as ever.

So in short, my advice is back off from shiny, wiped, marks. Don't fret over ghost images that you only notice because you're looking at the case under a magnifying glass--they do not mean you're over pressure as the chronograph will show, as will adding powder and seeing them go away.
 
Ejector Marks

Jon A,

the 92 gr Retumbo/AR2225 loads behind the 200 gr AB with fed 215m cap look a little polished in regards to where the ejector mark is or a couple do and the other to it is a ghost image.....................thing is I would not think that the 92 gr of Retumbo behind the 200 gr AB was anywhere near high pressure, but I will back of to 90 gr to ensure saftey. My brass is Rem and this is on it's first fireing.

I wonder if case capacity increases with the Rum after first fireing........if so pressures may recede.

When I have had ejector marks in the past with rifles it is usually associated with hard bolt lift so this is odd for me.

Thanks Folks.
 
Re: Ejector Marks

ejector marks will reduce with the same velocities in Winchester cases but they still appear.

Wonder if when a sako extractor is installed if that hole could be filled?
 
Re: Ejector Marks

Roy

You could have a smith make a plug to fill the hole up, but you would not have anything to push the case out.
 
Re: Ejector Marks

[ QUOTE ]
Roy

You could have a smith make a plug to fill the hole up, but you would not have anything to push the case out.

[/ QUOTE ]

oops, a bit of a brain fart there. Thanks! That'll save me from looking/sounding dumb when talking to the gun smith. /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/blush.gif
 
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