Trimming the head of a case, anyone???

[dellet]

flush with the top step and above the low step it does.

How does that work out when the chamber does not match the gauge?

This is the elephant in the room being ignored. Gauges are a fit, no fit device. They don’t tell why something does not fit. You have to measure.

What happens when your brass is at max trim length and your shoulder is pushed back .030”?
Drop it in your gauge and it sits at the low step because it’s now head spacing off the neck.

In the OP’s example the case is possibly too long for the chamber in one of three places. The neck, the shoulder or body. Without an actual measurement of both chamber and sized case, it’s a mystery. All we know is that if you cut a little bit off the case head, the bolt closes easier. That really doesn’t even tell you that the problem is not diameter.

The only clue we have is that he stated putting marking die on the shoulder and base, left marks on both. If you have marks on top and bottom, and the bolt won’t close, it’s too long. You can take it off the top or bottom to make it fit. Either way the distance between base and shoulder changes. One just might make more sense than the other. One is a work around, the other actually solves the problem.

What this sounds like is a poor sizing die, chamber match. It could be as simple as a shell holder out of spec. But this is why actual measurements are needed. How often are there post of “I ran my die down all the way to the shell holder, and the brass won’t chamber”? It’s just not uncommon. What is uncommon is suggesting cutting the case head down to fit. This is a first for me to read.

Truing the case head to the body is a completely different discussion.

If the OP would simply measure the base of the case head to the .400 diameter of case that does not fit, the answer would likely be revealed.

No body cares if a headspace gauge fits the chamber, or if the sized case fits the chamber gauge. When the brass won’t fit the chamber, when both those pass, what the gauges are telling you is very simple, “get a measuring tool, a spec sheet, compare and solve the problem.

 

[over_thetop]

Dellet

I use Hornady headspace gauges and only my case gauge to see the trim. However... when I get my headspace where I want it, it ALWAYS falls in where I said on my case gauges, with Dillion and Wilson gauges. I was just commenting on the reply. We tried to convince him about the face of the head is really not worth looking at. Don't know if he's there yet. If he isn't looking at the bolt face for brass, from hot loads, from extracting, then maybe he should.

“get a measuring tool"

Or use plastigauge.

 

[dellet]

Dellet

I use Hornady headspace gauges and only my case gauge to see the trim. However... when I get my headspace where I want it, it ALWAYS falls in where I said on my case gauges, with Dillion and Wilson gauges. I was just commenting on the reply. We tried to convince him about the face of the head is really not worth looking at. Don't know if he's there yet. If he isn't looking at the bolt face for brass, from hot loads, from extracting, then maybe he should.



Or use plastigauge.

My basic point was, size brass to fit the chamber, not any gauge. If the die is not capable of that, either get a barrel that fits your die, or a die that fits your barrel.

Think about Wilson gauge. For years his was specifically a headspace gauge designed to check headspace only. The diameter was such that you can insert fired brass. When the Chamber gauges first hit the market, the number complaints and threads about his headspace gauge being faulty were off the charts. It was not designed to check diameters. Now he make both headspace and chamber.

Op has an instant indicator, again almost useless for this application. It’s basically a comparator. But if he were to zero the indicator on the go gauge, and check it against his sized brass that doesn’t fit, it might confirm base to datum being longer. Still won’t be an actual measurement, but will show he needs to set the shoulder back more, or look at diameters.

I would just slide a feeler gauge between the case head and shell holder to lift the case a couple thou when sizing and see if that doesn’t solve the problem.

 

[over_thetop]

Ok... I reckon I have to drop it here

facing the case head and mouth and found out that indeed, it does improve chambering/bolt drop

If he faces the case head, which I never heard of such a thing, and never heard anyone doing it, would does what I do, bumps the shoulder, typically speaking. Ya measure HS from the case head to datum.

 

[Sixgun]

You're checking your headspace on the shoulder and not the neck, right? If you full length size, have a SAAMI spec chamber and bump your shoulder back .002 with the case trimmed within range your bolt should fall without resistance. You really should anneal after every firing too..it resets the neck tension and keeps the shoulder from springing back.

 

[dellet]

Ok... I reckon I have to drop it here



If he faces the case head, which I never heard of such a thing, and never heard anyone doing it, would does what I do, bumps the shoulder, typically speaking. Ya measure HS from the case head to datum.

Exactly.

The other issue becomes any thing more than just a skim of the case head runs the risk of a primer setting proud of the case head. Which can be corrected, if that’s just way too much brass prep.

 

[Thor357]

Go/no-go gauges have absolutely nothing to do with sizing brass to fit a chamber. All they do is confirm that the chamber is within a .010” spread. Or whatever the spread is on the SAAMI drawing.


If the die is not resizing the brass to fit within that spread, the only way to know that is to measure the brass from the base to the designated datum point diameter on the shoulder.

Just because the case fits a chamber gauge, is no guarantee it will fit your chamber.

No offense intended. But if you are expecting a set of go/no-go gauges to insure your brass will fit a chamber, you’re using them wrong.

Actual measurements are needed.

Yes, You are correct, go/no-go gages have nothing to do with sizing brass to a chamber. I was just stating that I know how to use them.

I have comparator gages to measure my brass from the base to the datum point and I also know how to use them.

Again, I know that a chamber gage does not guarantee that a case will fit a chamber. I know how to use a chamber gage.

I do not use go/no-go gages to insure my brass will fit a chamber, I use them to make sure my bolt closes when it's supposed to and to make sure it doesn't when it's not supposed to.

I measure EVERYTHING that I can with the tools I have. I have a file cabinet full of notes and sticky notes all over my work station with measurements I've taken.

Thanks for your input though.

 

[Thor357]

Some rifles just shoot better with certain bullets. I can clearly see groups consistently better with certain bullets. I have shot about 10 different bullets in my rifle. Of all the off the shelf non custom match bullets the 60 gr Sierra Varminter clearly shoots smaller than anything else. I have shot a Barts 68 gr Trophy Match. definitely consistent smaller groups. I shoot a 6BR and a 6BRX for GH hunting. I think I may have got a barrel better than most. The 6BRX shoots under 1/2" when FF. With the price of bullets it's hard to try 5-10 different bullets. I settled on anything under 1/2" is good enough. Finding a good place to hunt is more important than constant tinkering. Been reloading since 1970.

Yes, in the relatively short time I've been in the hobby of target shooting (5.5 years), I've learned that some bullets just do better in my rifles than others.

I'm not a hunter, nothing against hunting, I'm just too squeamish and lazy to go through the headache that comes with hunting. That's not to say I haven't hunted, I have. That's how I found out that I'm not a hunter. I am strictly a target shooter, from 100 yards to 600+ yards.

 

[Thor357]

Exactly.

The other issue becomes any thing more than just a skim of the case head runs the risk of a primer setting proud of the case head. Which can be corrected, if that’s just way too much brass prep.

Yes, I just pretty much just skim the face of the head. I do not trim so much off the head that a primer will come anywhere close to sitting proud.

I agree, it is more case prep than I prefer. Nice thing is that this prep is a one time thing...I hope. It's only recently that I have run into this issue. I have reloaded thousands of rounds and never encountered this issue before. Why I'm experiencing this now? I haven't a clue. That's why I posted the OP.

By the way, doing what I've been doing as of late seems to be working. I'll know more tomorrow when I head out to my friends ranch and shoot.

 

[Thor357]

You're checking your headspace on the shoulder and not the neck, right? If you full length size, have a SAAMI spec chamber and bump your shoulder back .002 with the case trimmed within range your bolt should fall without resistance. You really should anneal after every firing too..it resets the neck tension and keeps the shoulder from springing back.

Yes, I am checking the headspace via the shoulder (datum point).

The chamber is on the tighter side of SAAMI specs according to Troy at Savage.

I bump the shoulder to 1.5-2.0".

My bolt normally drops freely when I do this, just not recently.

Do a search either on this forum or Google and you'll get so many varying opinions on annealing, it's mind boggling. I chose to anneal about every 5th firing, give or take, because it's rather time consuming and I'm old and lazy.

 

[Thor357]

so how much do you set the shoulders back ? And do you try them on a completely stripped bolt ?

About 1.5-2.0

Yes, the bolt is completely stripped.

 

[Thor357]

How does that work out when the chamber does not match the gauge?

This is the elephant in the room being ignored. Gauges are a fit, no fit device. They don’t tell why something does not fit. You have to measure.

What happens when your brass is at max trim length and your shoulder is pushed back .030”?
Drop it in your gauge and it sits at the low step because it’s now head spacing off the neck.

In the OP’s example the case is possibly too long for the chamber in one of three places. The neck, the shoulder or body. Without an actual measurement of both chamber and sized case, it’s a mystery. All we know is that if you cut a little bit off the case head, the bolt closes easier. That really doesn’t even tell you that the problem is not diameter.

The only clue we have is that he stated putting marking die on the shoulder and base, left marks on both. If you have marks on top and bottom, and the bolt won’t close, it’s too long. You can take it off the top or bottom to make it fit. Either way the distance between base and shoulder changes. One just might make more sense than the other. One is a work around, the other actually solves the problem.

What this sounds like is a poor sizing die, chamber match. It could be as simple as a shell holder out of spec. But this is why actual measurements are needed. How often are there post of “I ran my die down all the way to the shell holder, and the brass won’t chamber”? It’s just not uncommon. What is uncommon is suggesting cutting the case head down to fit. This is a first for me to read.

Truing the case head to the body is a completely different discussion.

If the OP would simply measure the base of the case head to the .400 diameter of case that does not fit, the answer would likely be revealed.

No body cares if a headspace gauge fits the chamber, or if the sized case fits the chamber gauge. When the brass won’t fit the chamber, when both those pass, what the gauges are telling you is very simple, “get a measuring tool, a spec sheet, compare and solve the problem.

Hmm...I do check for OAL of the case and I trim them to 2.005".
My max chamber length is 2.0460 according to the Sinclair gages I have so my cases are well within that dimension.

I don't possess the tools to measure the true dimensions of the chamber for this rifle.

As for my sizing die. I hope it's not the sizing die, I paid a pretty penny for it. It's a Forster small base die.
I've had for about 2 years. I shoot a lot, at least I shoot a lot to me, about an average of 200-250 per week year round. Is it possible my die is worn out? Why did this issue suddenly show up. Up until about a week ago, everything was fine. I've cleaned the die and still the issue persists.

I measure each and every case with my gages and then insert the prepped cases into the rifle to confirm FFF. Usually everything is fine but then I get one that just won't play like the others. Why?

What measuring tool(s) do I need.

Spec sheet? You mean like what I've got from SAAMI?

Why wasn't this a problem 2 weeks ago but is now? What changed?
Did I do something different or has something about my rifle changed, my dies, my presses, my shell holders, my...?

 

[dellet]

Hmm...I do check for OAL of the case and I trim them to 2.005".
My max chamber length is 2.0460 according to the Sinclair gages I have so my cases are well within that dimension.

I don't possess the tools to measure the true dimensions of the chamber for this rifle.

As for my sizing die. I hope it's not the sizing die, I paid a pretty penny for it. It's a Forster small base die.
I've had for about 2 years. I shoot a lot, at least I shoot a lot to me, about an average of 200-250 per week year round. Is it possible my die is worn out? Why did this issue suddenly show up. Up until about a week ago, everything was fine. I've cleaned the die and still the issue persists.

I measure each and every case with my gages and then insert the prepped cases into the rifle to confirm FFF. Usually everything is fine but then I get one that just won't play like the others. Why?

What measuring tool(s) do I need.

Spec sheet? You mean like what I've got from SAAMI?

Why wasn't this a problem 2 weeks ago but is now? What changed?
Did I do something different or has something about my rifle changed, my dies, my presses, my shell holders, my...?

Looks like there is a lot to sort out here. Below is the SAAMI drawing with the most common trouble spots marked that might cause a case to keep the bolt from closing.

The number you gave, overall case length, rarely happens and with your numbers isn’t likely a problem. But that length and spot in the chamber is not where the cartridge should come to contact in the chamber. That length is marked in red.

The base to shoulder length is headspace, marked in blue. This is the critical number. The length is 1.630”- 1.640” min/max and is measured base to the .400” diameter of the shoulder. This is the most common place for your problem to happen. This is the critical measurement. That will let you know your chamber length without a tool. A fired case should measure between those numbers. Example a fired case measures 1.635”, after sizing 1.633”.
Do you have a tool to measure that?
if so what was it?

Marked in yellow is where the small base die should be sizing. The problem is that the normal shell holder depth is .125”. The web portion is the first .200” of the case. The die only sizes .075” of that. If the lower portion has expanded, the only way to correct it is to roll size the case, or get the case up farther in the die.



Since trimming the case head allowed the bolt to close freely, either the base is too large and is stopping forward movement, or the blue measurement, headspace, the shoulder contacting the chamber is stopping forward movement. That’s why that number is needed.

What’s changed in the last few weeks.
The die did not likely where out, but it’s possible an adjustment moved.
The brass got harder from another firing, the brass may not be holding the shape of the die when removed. This would show in a before and after sizing measurement. Cure is to screw the down more so it sizes .004”, and holds at .002”. Or anneal the brass.
Possibly a carbon build up in the chamber.

note that I used chamber dimension, this will be minimum chamber size. Your case can be slightly larger than maximum cartridge, shown above, and still fit the chamber.

So if your numbers are correct, real measurement, and the bolt won’t close, it’s safe to say the chamber is the problem. It’s not likely that it collapsed, so maybe a very aggressive cleaning and a look with a bore scope to confirm.

I'm basing everything on your statement that removing brass from the case head and or mouth of the case allowed the bolt to close freely. This cured only the symptom if it was solved by trimming the base.

 

[over_thetop]

Man what a rabbit hole. Sorry Alice you’re on your own.

 

[over_thetop]

Good point!
However, isn't the head of the case the thickest/strongest part of the head? Should it not be affected all that much if any by the pressure generated?
What's happening is after re-sizing, I run into some stiff chambering (no bullet, primer or powder in the case). This hasn't happened before and I have no clue as to what's causing this. It doesn't happen with every case but enough to be concerning. I have a bore scope and the chamber looks fine.
I have seen results from my "experiment" but it doesn't work for all cases. My question is why is this happening?

 

[dellet]

This is why you measure, and why if it fits it ships gauges don’t always work. This is also why new brass is often below minimum SAAMI Spec. Maximum cartridge may not fit minimum chamber.

 

[Bill K]

Seems to me that some are way overthinking this. After one or two firing and forming of the case in a given rifle, if it is then prepped and reloaded and kept for that same rifle/chamber, there should be no problem with it not fitting into that same chamber.
Or am I wrong ? Just keep each rifle's brass for the same given rifle/chamber.

 

[358WCF]

Most have been reloaded quite often, some just once or twice.

I haven't read all the way through this thread, but it seems you may have answered your own question all the way back in post #3 re: your brass.

 

[Webster]

Hmm...I do check for OAL of the case and I trim them to 2.005".
My max chamber length is 2.0460 according to the Sinclair gages I have so my cases are well within that dimension.

I don't possess the tools to measure the true dimensions of the chamber for this rifle.

As for my sizing die. I hope it's not the sizing die, I paid a pretty penny for it. It's a Forster small base die.
I've had for about 2 years. I shoot a lot, at least I shoot a lot to me, about an average of 200-250 per week year round. Is it possible my die is worn out? Why did this issue suddenly show up. Up until about a week ago, everything was fine. I've cleaned the die and still the issue persists.

I measure each and every case with my gages and then insert the prepped cases into the rifle to confirm FFF. Usually everything is fine but then I get one that just won't play like the others. Why?

What measuring tool(s) do I need.

Spec sheet? You mean like what I've got from SAAMI?

Why wasn't this a problem 2 weeks ago but is now? What changed?
Did I do something different or has something about my rifle changed, my dies, my presses, my shell holders, my...?

Don't get hung up on all this measuring and chamber dimension. Tinker with powder type charge, overall length and jump. You probably won't see much improvement with neck tension, just go witth 0.002" tension.

Check out the load map stuff on this website:

You are being redirected...

 

[bozo699]

I have an optical comparator as well as the Hornady gages. They indicate all is square after trimming but I still have a few cases that chamber somewhat stiff.
Does my concern warrant all this fussing around? I doubt it but I'm an odd fellow and stuff like this bugs me. This cr@p hasn't occurred until recently. Rifle still shoots great but...

Must be nice having your own optical comparator!… when I worked for ATK I had access to one and used it to make my own seating stems so they matched my bullet profile perfectly.
Wayne