ejector marks even on light loads, any ideas

[climb-101]

sorry if this has been gone over 100 times before. I did some searching but didn't find any thing. I bought the gun used and its claimed to have about 75 rounds through it,

my issue is I started doing some load development for my 338 LM. it has a stiller tac 338 action and rock creek barel, jewel trigger. I started my loads off at the bottom level in the Sierra manual and went up from there in half grain increments. (specs below)


300g SMK
lapua brass (once fired from my rifle)
neck sized only
federal 215 primers
83g-92g of H1000. (1/2 grain increments)
.025 jump for the bullet (bolt face to lands is 2.990 / loaded length is 2.965)

here is my problem
I fired 1 of each loaded round from 83g-89.5g then stoped. there was no hard bolt lift, the primers all look the same for all the fired ones just flattened a little but the edges are still round.

when I looked at the cases I can see ejector marks even on the lightest of the loads.
they get more noticeable as the power increased, once I get to the 85-86 area it's starts to get the little smear mark along with the ejector mark.

I figured I would get a Wilson gauge to check headspace and it appears to be good. specs below

Wilson gauge - 2.724"
never fired brass in gauge ( only sized) - 2.725"
fired round in gauge - 2.726"

does any one have any insight as to why I'm getting ejector marks. is it the way I'm loading or something with the gun? thanks for any insight

 

[climb-101]

here is a pic of the primers and the marks. the ejector mark on the first case is right by the L

 

[Wachsmann]

from what I can only say from the pics and experience is the 88.5 looks like it is over pressure. the primer looks like it is cratered quite a bit. I would think if it was removed it would show some flatting around the edge. Also it looks like there was some gas escaping by the primer. Hopefully someone else will offer more susgestions. I would try to load some at sammi length or back off the lands like to 80thousands and see if you get the same results. I have a 6.5x284 that show pressure a little eairly compared to most but I can usually go to book max load on the gun during the winter with no issues.

 

[climb-101]

thanks for the info. I will be heading back to our ranch this weekend so I can do some playing around with the gun and some loads. I will start by trying a round at the sammi specs. I just measured a loaded round and it is 3.713 OAL. I will seat it another .032 in and see what it does

I will also take the crono that I forgot last weekend and see what the pressures is.

thanks for the help

 

[barefooter56]

thanks for the info. I will be heading back to our ranch this weekend so I can do some playing around with the gun and some loads. I will start by trying a round at the sammi specs. I just measured a loaded round and it is 3.713 OAL. I will seat it another .032 in and see what it does

I will also take the crono that I forgot last weekend and see what the pressures is.

thanks for the help

climb-101,
You may want to have a good gunsmith check that rifle out before you do any more testing. Maybe there was a "reason" it was sold off after 75 rounds. Other than the fact 338 Lapuas are expensive to load. Check the head-space and have a chamber cast made so you can see whats up. Just a suggestion. If the chamber is that tight on the case body you MAY not have enough clearance in the neck of the chamber to allow the neck to release the bullet without building pressure. Chamber cast will show that.

 

[climb-101]

I plannin bringing the gun back and taking it to a gunsmith here in town and seeing what he has to say about it and giving it a good once over. I figure while I'm up at the ranch and all the loading stuff is ther I will try one round at the sammi specs and see if it's still giving me an ejector mark.

 

[barefooter56]

I plannin bringing the gun back and taking it to a gunsmith here in town and seeing what he has to say about it and giving it a good once over. I figure while I'm up at the ranch and all the loading stuff is ther I will try one round at the sammi specs and see if it's still giving me an ejector mark.

climb-101,
Patience can be a virtue brother. Just saying. That neck dosent have sufficient room to expand and release that bullet on time it could all end in tears. Safety sir.

 

[climb-101]

I do agree. better safe than sorry.

I will just bring the gun back and have it checked out. what are my options for fixing it if this happens to be the issue with it?

 

[barefooter56]

Ask the gunsmith if he can re-ream the chamber maybe. He will know for sure. good luck!

 

[Laelkhunter]

What is the case length after neck sizing? The case will stretch the most on it's first firing. Case length, if too long could cause excessive pressure.

 

[climb-101]

after the first shot I trimed them to size.

 

[royinidaho]

Will a bullet easily slide into the fired case mouth?

Also, I seem to have that problem when case necks are a bit thick.

Just a couple of things to check...

 

[climb-101]

I just had the gunsmith look at the rifle. he said he can see some marks where the tool was drug when the bolt was drilled for the ejector. he did a little cleaning up on it and told me to take it and try it. he checked the chamber with a scope and gave it a once over and said there were a few things that he dosnt like and would do different such as the type of being compound, brazed bolt handle, and some little stuff like that but dosnt see any major issues or signs of there being over pressure. said take it out and have fun with it and when I ready for another gun to let him him know.

I did check to see how a bullet will slide in a fired case and it slides in with a little drag, enough that it will hold the bullet in if its tipped up side down. my STW is easer to slide the bullet in and won't hold itself in if I flip it up side down. I think I will get a neck turning tool, if nothing else they will all be uniform.

 

[climb-101]

I did some quick measuring tonight on the cases. the neck measurement according to the Sierra book is .372,
my fired cases measure .372 outside and .340 inside and the SMK is .337
loaded cases measure .367

I also measured the neck thickness and its .014 thick.


so what I'm seeing from the numbers the case is expanding at the neck .003 to let go of the bullet. I am assuming that this is plenty of expansion and that the chamber isn't too tight. any body have any other thoughs on these numbers, possable measurements of there own to compare them too