some rounds wont chamber Bat 3L 6BR

T

thedrifter

Guest
Hey guys, I need to bounce what I’m thinking because I am questioning my thoughts.

I am a prone shooter and was shooting a match this weekend, first time at 600 yards with this rifle, I did manage a high master score of 591 and 29X's (12" Ten & 6" X ring) so no question the rifle shoots.

Here is what happened, out of the 60 rounds fired, 4 would not chamber, and about 10-15 were difficult to chamber. So today I checked and rechecked all my measurements... this is what I found using a 20 round sample of yesterdays fired brass.

Bullets are .020" off the lands Berger 105s VLD Target
I Full length Size with a Forster Die using the expander ball & Redding Press

So, I decided to look closer at the head space, well with my tool (similar to stony point 1.1340" tall), measuring off the center of the shoulder to the
base of the cartridge I had:
12 @2.3090
4 @ 2.3085
4 @ 2.3080

The 4 cases that wouldn’t fire measure 2.311. I believe this .002” could be a cause to my issue. This made me take a closer look at my Die to see what was wrong.

Before I get to far on this, I will admit that I used the standard screw the die down and go a ¼ turn extra, turns out that is wrong and I am going to fix my ways.

Back to my story so looking to set the shoulders back the correct amount I determined I need to have my die set to measure 2.307 with my tool.

I removed the expander ball, backed the die off the shell holder and proceeded to size two cases, and to my surprise both cases came out at 2.3100… they stretched, so I measured the necks

Before sizing (Fired) .271”
After sizing (No expander ball) .260”
After sizing with expander ball .267”

Therefore, I think I think my solution is to send my die off to be honed to .267” and stop using the expander ball.
Should I also order the competition shell holder set from Redding?
Anything else i need to consider to prevent theses troubles in my future?
 
hmmmmmmmmmmmmmmm
Dump the expander ball.
Use a bushing die for the neck or neck and body.

The worst thing to do to a case is to pull an expander thru it if you are
trying to build truely accurate ammo.
 
Depending on how tight that expander ball is in the sized neck, you could actually be stretching the case back as you pull up on that handle.

But as was just said, accuracy minded shooters do not use expander balls. Get a good set of Redding Competition Dies, (body die, decapper/neck die, and seater), and your problems will be solved.

Congratulations on your great score.
 
Just out of curiosity...were all the cases the same lot and been fired the same number of times?
 
jackie schmidt said:
Depending on how tight that expander ball is in the sized neck, you could actually be stretching the case back as you pull up on that handle.

But as was just said, accuracy minded shooters do not use expander balls. Get a good set of Redding Competition Dies, (body die, decapper/neck die, and seater), and your problems will be solved.

Congratulations on your great score.
Click to expand...

Not a thing wrong with Jackie's advice, but if it were me I'd send three of those cases that chambered well off to Lynwood Harrell (Harrell's Precision) and have him send a die with will work with your chamber. While you're at it, tape a quarter to that die with the expander ball and throw it away.

Rick
 
Thank you,

this is that i thought was the case, ill be dumping the expander ball, but do i really need to switch dies? sending off for $10 to have the die resized seems like a fair price. unless there have been problems with this?

as for the Brass its all Norma, i received it as once fired and I believe to to be from the same lot, it was factory loaded ammo shot through an European 300m rifle.
 
your die as it sits is most likely sizing the neck too much(and thus the expander).
you need to do some measuring and determine how much neck tension you want.
do the math and have the neck opened up....hopefully it will be straight.
the other option is to have the die cut for std 1/2" neck bushings
 
There is one more thing that I would suggest that you determine about the relation between your chamber and die...the amount that a fired case is reduced in diameter, from sizing, where the coverage of the chamber ends, just above the extractor groove. You could have a die that is too large in that area for your chamber. This could be exacerbated if the chamber of the 300 M rifle that it was fired in was significantly larger than yours. If that was the case, it might take a smaller die to reliably size every one of your once fired cases so that they are smaller than your chamber. Without looking at this area, you could be misreading the cause of your chambering issue. Personally, I like to create a reference case by neck sizing and firing one several times while tracking its shoulder to head growth. Keep your lugs greased while doing this. An alternative method would be to work with a case fired one time in your chamber (that went in easily) and check to see what the exact fired primer protrusion is, and add this to the head to shoulder dimension measured after removing or reseating the fired primer below flush. This should get you pretty close to the maximum dimension of a multiple fired neck sized case.
 
Using once fired brass from another rifle in yours is asking for problems. Kind of surprising you only had the few issues you had.
From my experience you would be way better off tossing them
 
Greyfox said:
Not a thing wrong with Jackie's advice, but if it were me I'd send three of those cases that chambered well off to Lynwood Harrell (Harrell's Precision) and have him send a die with will work with your chamber. While you're at it, tape a quarter to that die with the expander ball and throw it away.

Rick
Click to expand...

Gotta agree with Rick on the Harrells advice.
Not sure about throwing away the old die with a quarter , seems like a waste of a quarter.
 
Bite the bullet, so to speak, and buy a FL die with a couple of interchangeble bushings for the neck. Start with new cases and go from there. I recommend more than one bushing because your cases will wear harden and one bushing is not enough. If you anneal, then one bushing might be adequate.

There's a problem that causes the cases to be/feel tight related to the base of the case rather than the shoulder. Make sure you always understand where the problem is! Sometimes it's the length of the case and sometimes it's the base diameter of the case. You can determine which it is by turning the sizing die such that it sizes a bit more and see if the tight case remains tight. If it remains tight then the problem is an expanded base. The base can be corrected with a small base die...or make new cases.

Make ESPECIALLY certain that your loaded round neck diameter is not greater than the chamber neck diameter.
 
Just an update on what I have found.

In short it turns out the best solution for my problem was the small base die. It was only the Norma brass that was having issues and the Lapua that was only fired from my rifle worked flawlessly.

I purchased the Redding competition she'll holder set, and a Redding small base re-sizing die.

I isolated three rounds that would not chamber and proceeded to properly set the head-space -.002". Using the shell holders I found the the +.010 gave the closest to this number, this makes me think my Forster die is a little long. Am I right to think this? Anyways after they were set back I could still not chamber the 3 rounds, so I proceeded to use the new small base die and poof, they all fit and functioned perfectly. So I went ahead and used the small base die on that 50 round batch "and function tested" now I look forward to testing these at the range.

There was also a learning experience not to go straight to the small base die with a fired case, it was promptly stuck, requiring some persuasion to be removed.

Hopefully this will help improve consistency having the shoulders set tighter too. Before with the standard shell holder it set back a significant amount,
 
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John Kielly said:
I've heard that mixing headstamps can contribute to a lesser degree of accuracy.
Click to expand...

oh im not mixing the brass,

I have 100 Lapua Cases that I purchased new and several hundred Norma cases that were once fired from a European 300m rifles. the Norma were giving me the fitting issues, I suspect from a fatter chamber that allowed them to expand more.
 
I predict

If you shoot this rifle, barrel combination very long I predict you will end up with a Harrels or similar semi-custom die, and setting the Norma brass aside. I love the concentricity of Norma brass, but it is just too soft with semi hot BR loads. I had a good supply I thought I would use in my 30 BR it just required too much resizing, way too much.
Dick
 
777

thedrifter said:
Norma were giving me the fitting issues, I suspect from a fatter chamber that allowed them to expand more.
Click to expand...

I suspect you have hit the nail squarely on the head , Brass has somewhat of a memory. Once fired in a larger chamber no amount of resizing really brings it back to original size. A sufficiently aggressive resizing will usually get the brass to chamber well but it will attempt to return to it's old dimension after firing and is a leading cause of hard extraction or at least bolt click.
Dick
 
thedrifter said:
Thank you,

this is that i thought was the case, ill be dumping the expander ball, but do i really need to switch dies? sending off for $10 to have the die resized seems like a fair price. unless there have been problems with this?

as for the Brass its all Norma, i received it as once fired and I believe to to be from the same lot, it was factory loaded ammo shot through an European 300m rifle.
Click to expand...


You need to smallbase size that brass. If it is going in a Lapua chamber, the previous chamber was very generous from the 300m rifle. (I have some of the same brass)

I sent my die to Forster and had them ream the neck, still use the expander ball (but it really doesn't hardly touch the neck anymore). I have shot many 200-13+x with my setup from a prone gun too.

I bet your chamfering issue was from the base being not sized enough from the Forster die. Get a Redding smallbase ring die and that problem will be gone. The Forster dies will be fine for future firings.
 
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