Effect of trimming cases longer on pressure

[jlorenzo]

So I am going to start letting my brass get longer than I have been to see if I can minimize the carbon ring.
I was trimming 223 brass to book 1.750" but looking at my throat with a borescope 1.755" seems to fit a little better while still leaving some space.

Will the longer brass have any effect on pressure? Say I have a load that is on the hot side, would this be enough to push it over the edge?

 

[6Creed73]

The neck length shouldn't have any effect on pressure and the length you are proposing is within saami spec. But I'd recommend getting a sinclair chamber length gauge to measure your chamber. They are just a few bucks and it's good to know.

You can most likely go longer..but not so long that case expansion will damage the neck. That's where knowing your chamber length comes in handy.

 

[jlorenzo]

The neck length shouldn't have any effect on pressure and the length you are proposing is within saami spec. But I'd recommend getting a sinclair chamber length gauge to measure your chamber. They are just a few bucks and it's good to know.

You can most likely go longer..but not so long that case expansion will damage the neck. That's where knowing your chamber length comes in handy.

I will look into that. I have been using a borescope positioned at the neck from the end of the barrel then inserted a case. I can see right where the end of the neck sits in relation to the throat.

 

[6Creed73]

Here is the sinclair gauge. You just put it into a shortened, fired case and close the bolt, which pushes the gauge into the case. Then you simply eject it carefully and measure with calipers, then you know exactly how long your chamber is.

SINCLAIR INTERNATIONAL Sinclair Chamber Length Gage

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