ejector marks even on light loads, any ideas

[barefooter56]

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

climb-101,
Looks like you have plenty of clearance for adequate release of the bullet and your gunsmith gave the rifle his OK. You may want to make a dummy round to the lands using a once fired, neck sized case from that rifle that still chambers smoothly. After you have the dummy round made . Polish the tarnish off the bullet with some 0000 steel wool , chamber the round and check for lands marks on the bullet. If there are lands marks of any length. Begin to seat the bullet lower in stages until the lands marks are about the same thickness as the mark of the point of a really sharp #2 pencil point makes on paper. Be sure to polish the lands marks off the bullet each time before you re-chamber it after seating the bullet lower. Now measure this round with a set of calipers and a bullet comparator of your choice and a magazine length dummy round loaded in a fired case. Lets see how close to the lands your mag length ammo is to see if may be an issue. Process = eliminate one thing at a time , test and note result as you go along.

 

[Bill Johnson]

A few thought:

I see no signs of high pressure. Pressure high enough to cause primer cratering will also flatten the primer to the point it fills the bevel in the primer pocket. That's not there.

Those marks and primer issue, without other signs of high pressure, are generally related to the bolt. When I see the primers like that, the first thing I think of is the firing pin hole in the bolt face is too big.

Secondly, as to the ejector mark issue, if you look at Stillers Precision, the maker of your action, you will see this:

NOTICE: A few actions were shipped with ejectors too long. IF your ejector protrudes past the end
of the bolt it can cause issues with feeding. Contact us for a replacement.​

If it was me, I'd send the whole thing back to them and make them fix the bolt issue to include the firing pin hole and ejector.​

 

[4xforfun]

Just a thought, but have you checked to make sure that the chamber is clean and dry? Oil/grease is NOT your friend in this instance!!

 

[climb-101]

climb-101,
Looks like you have plenty of clearance for adequate release of the bullet and your gunsmith gave the rifle his OK. You may want to make a dummy round to the lands using a once fired, neck sized case from that rifle that still chambers smoothly. After you have the dummy round made . Polish the tarnish off the bullet with some 0000 steel wool , chamber the round and check for lands marks on the bullet. If there are lands marks of any length. Begin to seat the bullet lower in stages until the lands marks are about the same thickness as the mark of the point of a really sharp #2 pencil point makes on paper. Be sure to polish the lands marks off the bullet each time before you re-chamber it after seating the bullet lower. Now measure this round with a set of calipers and a bullet comparator of your choice and a magazine length dummy round loaded in a fired case. Lets see how close to the lands your mag length ammo is to see if may be an issue. Process = eliminate one thing at a time , test and note result as you go along.

I measure the bolt to the ogive the other night and was getting 2.990 and and set up a .025 jump to the lands off that number.

I just remeasured and got the same 2.990 when it just touches the land I think but if I push on the OAL gauge just the slightest bit I can feel it push in further and I measure 3.029 ( possable what I'm feeling is the bullet sliding over the lands to the ojive?). even with the 300SMK touching the land I have lots of room in the mag box.

A few thought:

I see no signs of high pressure. Pressure high enough to cause primer cratering will also flatten the primer to the point it fills the bevel in the primer pocket. That's not there.

Those marks and primer issue, without other signs of high pressure, are generally related to the bolt. When I see the primers like that, the first thing I think of is the firing pin hole in the bolt face is too big.

Secondly, as to the ejector mark issue, if you look at Stillers Precision, the maker of your action, you will see this:

NOTICE: A few actions were shipped with ejectors too long. IF your ejector protrudes past the end
of the bolt it can cause issues with feeding. Contact us for a replacement.​

If it was me, I'd send the whole thing back to them and make them fix the bolt issue to include the firing pin hole and ejector.​

I took a look at the bolt face and I can easily see where the hole is shaped just like the primers. its kind of pentagon shaped at the bolt face. I will give stiller a call and see what they have to say. I will post a pic if I can get a good shot of it

 

[barefooter56]

I measure the bolt to the ogive the other night and was getting 2.990 and and set up a .025 jump to the lands off that number.

I just remeasured and got the same 2.990 when it just touches the land I think but if I push on the OAL gauge just the slightest bit I can feel it push in further and I measure 3.029 ( possable what I'm feeling is the bullet sliding over the lands to the ojive?). even with the 300SMK touching the land I have lots of room in the mag box.







I took a look at the bolt face and I can easily see where the hole is shaped just like the primers. its kind of pentagon shaped at the bolt face. I will give stiller a call and see what they have to say. I will post a pic if I can get a good shot of it

climb-101,
Make a dummy round with the bullet you used to get the 3.029 measurement. And follow steps above. Lets see how far (if at all) you are into the lands at the 3.029 comparator OAL ( base of the cartridge case to ojive of the bullet) and we can go from there. BUT first check with Stiller on the bolt. If they have to redo or put a new bolt in the rifle the measurements you have now MAY not be any good. Get the mechanical's right first.

 

[climb-101]

pic of the firing pin hole. if you click on the picture and enlarge it. you can see how it's kind of pentagon shaped and that's how the primers look as well

 

[climb-101]

climb-101,
Make a dummy round with the bullet you used to get the 3.029 measurement. And follow steps above. Lets see how far (if at all) you are into the lands at the 3.029 comparator OAL ( base of the cartridge case to ojive of the bullet) and we can go from there. BUT first check with Stiller on the bolt. If they have to redo or put a new bolt in the rifle the measurements you have now MAY not be any good. Get the mechanical's right first.

I had the same thought. I will be calling them this afternoon and see what they have to say.

 

[barefooter56]

Wow. never seen that before. Almost looks like the drill bit "walked" .

 

[Bill Johnson]

Something like that. Maybe one flute broke off before the bit came all the way through. That, with the ejector issue, in my opinion, calls for Stiller to fit a new bolt at their expense.

It's possible to bush the hole, change the ejector and they wouldn't have to reheadspace the barrel.

Things happen to good companies. It's how they handle it that seperates the world-class outfits from the also-rans.

 

[barefooter56]

Yep. Stiller is a good company. You shouldn't have an issue. Good luck!

 

[climb-101]

Yep. Stiller is a good company. You shouldn't have an issue. Good luck!

stiller was great to deal with. I think it was Russ I talked to yesterday. he had me send in some pics of the bolt and the fired cases. he called me back this morning and said it looks like someone tryed yo chamfer the firing pin hole for some reason but it's not enough to affect anything. As far as the ejector marks, he said drop the powder charge down more even though it's below the book, see what happens and shoot it over a crono and find out what the speeds are so pressure can be figured out. hopefully the weather is decent this weekend so i can do that and report back to him.

 

[Bill Johnson]

So your ejector sits flush with the bolt face when fully depressed and doesn't protrude beyond the bolt body as noted on their home page? It's not unusual for some actions to allow high pressure loads to leave an ejector mark like that on a case, so as long as the ejector meets Stiller's criteria, that's OK. Just wondering what they had to say about it.

Primer cratering, in and of itself without any other signs of high pressure, like hard bolt lift is not necessarily an issue either. What you do have to worry about is a primer failing to contain the pressure when it's deformed like that, though. Commonly called a "pierced primer", the hot gasses leaking into the action will erode the firing pin hole further, exacerbating the problem. I'd insist Stiller fix that but if they're adamant, you should consider switching primers to one with a harder cup. Federals are known to use the softest material. Switching to CCI or Tulas will reduce the cratering and give you a little better margin of safety.

Good luck!

 

[barefooter56]

climb-101,
+1 on what Bill said plus measure the cartridge case in the area above the extractor groove to see if the case has expanded more than .001 over new. Also , our manual calls for a stating load of 81.0 grains with a MAX LOAD of 85.2 grains . Approximate fill ratio shows 104% so its a compressed load in the big end. What manual were you using and how old is it?

 

[climb-101]

climb-101,
+1 on what Bill said plus measure the cartridge case in the area above the extractor groove to see if the case has expanded more than .001 over new. Also , our manual calls for a stating load of 81.0 grains with a MAX LOAD of 85.2 grains . Approximate fill ratio shows 104% so its a compressed load in the big end. What manual were you using and how old is it?

measuring the case is one thing the gunsmith here told me to do also. I have the mic sitting with the shells so k can check them before and after to see what there doing. I measured some of the fired ones vs some vergin brass and I couldn't see any differance but that was just with my caliper so I'm guessing if it did move at all it's less than .0005".

as far as the manual, I have the sierra manual. not sure on the year but I'm guessing it's about 5 years old. I think the bottom load in it for H1000 was 82.5 grains and the top load was 92 grains. I was going to load up a few rounds tonight from 80-82 in half grain increments and to the SAMMI specs for the length and see what the brass looks likes as well as what the crono says. hopefully this weekend I can get out to test them if the weather holds up