22BR Lapua zero freebore reamer

[AckleymanII]

^^^^^ This! ^^^^^

Those with ears, let them hear!

 

[Evan]

Here's what I'm talking about:

The bigger that gap is, the more carbon that can build up there.

 

[RAG]

Is there a reason that you want so much extra neck length on your chamber in front of the brass? I use a borescope to verify the trim length where my brass is just a few thousandths short of the transition to minimize how much carbon can build up there.

Don't want extra for sure...i like about .010 past brass so i dont have to worry about trimming for a while. My lot of brass has already grown, and once necked down, measures 2.573. So that would be 2.583...but i don't simply want a longer chamber (controlled by how far the smith runs the reamer in) with same length neck, as that would risk head separation. All that said, I'll probably just have the neck length extended by .015 and then trim accordingly.

 

[RAG]

Here's what I'm talking about:

The bigger that gap is, the more carbon that can build up there.

Right. I know. Thank you. Great picture!

I usually like to have about .010 gap and let them grow for a while, causeni don't like to trim too often. The way I look at it, regardless of whether you start with a 4 thousandths or .020" gap, carbon will build-up in there and pressure spikes will occur in a tight-neck chamber, as you let the brass grow unless you are trimming every firing. I always just make sure I attack the carbon.

Cheers!

 

[Ackman]

Those with ears, let them hear!

Some just refuse to hear.

 

[OKyote73]

Those cases will shorten after the initial fire form in my experience (3 different AI's and a 20/222)