9mm reamer depth

[4thquarter]

I am ready to ream my 9mm barrel and am having trouble finding the exact dimensions of the measurement from the barrel hood to the ridge.   Is it .754”.  What are most open 9mm builds set too?

[Steve RA]

Are you reaming the chamber or just extending the throat a little deeper ?

[4thquarter]

3 minutes ago, Steve RA said:

Are you reaming the chamber or just extending the throat a little deeper ?

Sorry I should have specified.  This is a new build with a blank barrel.  I am reaming the chamber to length, I want to load out to about 1.16 or so.   I have a dummy round and will keep checking as I go but want to check and see what the actual measurement calls for.  I understand cases are going to vary and I want to allow for the differences.

Edited July 4, 2019 by 4thquarter

[theWacoKid]

You can Google and find all SAAMI specs. 0.754" is max tolerance for brass so it's the minimum end of tolerance for the chamber. A go, no-go gauge set is your friend. 

 

https://saami.org/technical-information/cartridge-chamber-drawings/

 

 

Edited July 4, 2019 by theWacoKid

[Joedirt199]

You won't be able affect throat without affecting chamber case depth as well so watch the end of you brass to make sure you don't ream too deep to achieve the leade you want. What teamer are you using?

 

I reamed a few barrels without using go/no go guages. Load a few dummy rounds as close to what you want to use with the types of brass you plan to use. Use lots of oil for smoother cuts and clean often. Sammi specs are pretty generous and will give you a lot of wiggle room for your round to move front to back. Don't use much pressure and spin it freely with your fingers to get a nice smooth finish cut on your progress. Spin as you remove it to prevent gouges.

Edited July 12, 2019 by Joedirt199