Chamber Length?

[Rooster931]

I am sorry if I confused the two issues. I am speaking of trim length of the case. The OAL of the loaded cartridge would be much longer than 2.560. Once the seated bullet starts to protrude into the rifling you are no longer in the chamber.

 

[BrentM]

So am I wrong in thinking that this gauge for chamber length would help me determine how far to trim cases to avoid a carbon ring?

Yes, basically. Let's say you just trim to the recommended length. You clean the carbon every 50 or so...... you will likely never have a carbon ring. Now, if you go several hundred rounds without cleaning and using a good product to clean, you will develop a ring. I clean carbon and leave copper alone as a general rule. I have learned to clean carbon every 50-100 and I use boretech, a chamber guide, and nylon brush. My first round c;lean bore impact is good to go with this method.

 

[Ol' Red]

Yes, basically. Let's say you just trim to the recommended length. You clean the carbon every 50 or so...... you will likely never have a carbon ring. Now, if you go several hundred rounds without cleaning and using a good product to clean, you will develop a ring. I clean carbon and leave copper alone as a general rule. I have learned to clean carbon every 50-100 and I use boretech, a chamber guide, and nylon brush. My first round c;lean bore impact is good to go with this method.

That is basically what I do now. I clean the bore and chamber after 40 to 60 shots. Thank you Brent. I will continue on as I have been. Have a great day.

 

[DoneNOut]

Just peek at it! Another good use of Borescope.

The inside case mouth chamfer ring is .030 wide. Red arrow. It slides to the light/dark line in the chamber when bolt closes. So the width of the dark area is .060+. I know my primer pockets will give out long before the brass is stretched to that wall indicated by yellow arrow.

 

[Impulsive]

I use the chamber length gauges also. I find that the cut length of most chambers is usually longer than the "max cartridge OAL." Knowing the length of your chamber will allow you to run a longer neck, reducing the size of the carbon ring.
I have never trimmed a case to the "trim to length."

 

[Tiny Tim]

I made my own gages and measure once when I receive a rifle. I've not seen a chamber end anywhere near rhe case mouth unless a custom reamer. Best I can do is trim a bunch of brass to a consistent length for uniformity. Then let them grow and trim to uniform length occasionally. I haven't reached the end on a factory chamber. Last batch of Lapua 243 brass I purchased was .015" short of minimum trim length and got shorter making it into an AI format.
I just have to stay On top of the carbon ring. Your 7mm sounds about right.

 

[QuietTexan]

I haven't reached the end on a factory chamber

Pretty much same here. The only one I've hit is in standard 30-06 - and I'm almost certainly oversizing the brass with an FL die and making it grow.