using a chamber stub?

[djtjr]

guys i have a gun that i got with a chamber stub that was made with the same reamer and was wondering how it is used and what to do with it. i assume it can be used for seating depth adjustments just not sure how to do it or what else it is useful for. any help here is greatly appreciated.,
thanks and all the best,
don

 

[KeithR41]

Re: using a chamber stub?

Probably a head space gauge. You can measure shoulder bump with it.

41

 

[Da-Law-Dawg]

Re: using a chamber stub?

dj,

What you have is commonly referred to as a chambering aid.....have one for my Rock barreled FN .308.

Very simple to use to set your dies up.

It's a stub of the barrel that's cut using the same reamer used to chamber your rifle. Being that, it has the same shoulder and leade (throat) as your tube.

Here's whatcha do.......

Take a piece of brass sized to your rifle (no primer or powder needed), seat your preferred pill LONG in the brass. Seated long as stated, when you set it in the chambering aid, you'll feel it wobble as the ogive is in the lands but the shoulder isn't touching.......yet.

Bump your seating stem on your die in SMALL increments until is just settles in the aid with no wobble. Take your time and go slow. When the dummy round settles with no wobble, measure (I measure from the ogive) the dummy round and record the measurement for that bullet. That's the measurement at the lands for THAT bullet in YOUR rifle.

From that point, use that dummy round to set up your dies and adjust for seating depth from there.

Sorry to be so long winded.

 

[djtjr]

Re: using a chamber stub?

dawg thanks not long winded at all that was a great explanation.
d

 

[Hummer]

Re: using a chamber stub?

just wondering, does the stub have throat in it?

When I make them I used the same reamer and I run it in to about 1/8" below the shoulder. I trim back the front end till it has just a thin shoulder where the front of the chamber stops and none of the lead.


You can then look in and see exactly where your neck is in relation to end of the chamber. On a tight neck gun you place all your loaded rounds in it before going to range to make sure there is no oversize condition that would stop it from chambering.

You will be amazed how firm the loaded round feels in this set up. No wobble at all where with a SAAMI size chamber the neck is free to wobble around.

You have a first class set up.

You can also insert stub over fired case and measure from end of it to base of case with a dial caliper. Then run your FL die down on that case until you detect .001 to .002 shoulder set back and lock your die right there. This will give you longer case life.