Lengthening a Chamber by Hand Turned Reamer?

[fguffey]

I size cases for short chambers. When I cut a chamber I cut the chamber short then size/form cases for the short chamber, and then to the range and road test it.

When sizing cases for short chambers I place a feeler gage between the deck of the shell holder and head of the case. My favorite shell holder for sizing cases for short chambers is the RCBS shell holder, I can shorten a case from the shoulder to the case head by .010" with a RCBS shell holder.

And then there is that thing about bumping, reloaders believe they can bump the shoulder.

I have no ideal why you insist on the bolt closing on the go-gage. I would suggest you learn to verify a gage first and verify the length of the new over the counter factory loaded ammo. Your sizing die is destined to return the case to minimum length/full length sized.

F. Guffey

 

[fguffey]

Anyhow, If you were able to size cases for short chambers you would know the length of your chamber in thousandths. I understand for most that does not make sense but a reloader that can measure the length of the case from the shoulder to the case head can determine the length of the chamber in thousandths.

And then you said something about casting the chamber. There is only one person that can cast a chamber and determine the length of the chamber from the shoulder to the bolt face. As a rule the length of the chamber is not included in a chamber case.

F. Guffey

 

[hoz53]

Factory ammo is always shorter than a go gauge. Usually by .001-.006".

Hi Adam I believe that is true. In general I think their concern is that they will function for one shot and dont care what happens to the brass. Thanks

 

[hoz53]

Hoz,
I think you have the right idea to fix it yourself or have a local smith do it. You do need the right driver to make sure you do it right. This is kindo a touch thing. Use a t handle and keep forces balanced around the center to make sure you don't cut where you don't want to cut. --Jerry

Hi Riesel and carlsbad--You guys obviously are very knowledgeable in this area--Thanks for sticking with the thread. Here is what happened. I decided to rechamber the barrel and not mess with trying to ream the chamber deeper because I didnt want to mess up my reamer and I thought the chamber was crooked. It never shot well anyway so I removed the barrel from the action. I then decided to cerrosafe it to make sure of the crooked chamber and 3 grooves run all the way to the neck and the other three end about .080 from the neck. So I thought I would try rechambering it for sure and at least get a learning experience out of it. Today I thought Well I might as well try reaming the chamber by hand and see what I can learn doing that since I would be cutting it off some anyway. Oh and I lapped the lugs after I pulled the barrel. Anyway put barrel in vise, used alot of cutting oil and began reaming. I checked the depth of a go gauge in it first using a depth mic and checked and cleaned it often as I was reaming. I reamed it until I went what I thought was .002 deeper than cleaned it up and installed it back on action. Lo and behold when I stuck a no go gauge in the action and tried to close the bolt it did close with a little click at the bottom. So I overdid it a bit. I think lapping the lugs probably took a little and if I would have really wanted to save this chamber I would have went slower checking it on the action more. OF coarse the grooves still end where they did before- reaming didnt help that. Next up I only have enough room to mabie cut the threads off and rechamber, so I wonder if my new chamber will be any more concentric with bore--probably not but Ill find out and I know at least Ill get the headspace right. I will probably put a new barrel on it one of these days. Thanks for your help Hoz

 

[hoz53]

And go S-L-O-W and careful.....cleaning and checking often.

See my reply to carlsbad post.

 

[hoz53]

Anyhow, If you were able to size cases for short chambers you would know the length of your chamber in thousandths. I understand for most that does not make sense but a reloader that can measure the length of the case from the shoulder to the case head can determine the length of the chamber in thousandths.

And then you said something about casting the chamber. There is only one person that can cast a chamber and determine the length of the chamber from the shoulder to the bolt face. As a rule the length of the chamber is not included in a chamber case.

F. Guffey

Hey Guffey I do have several different bump gauges that give me relative measurements( case head to somewhere on shoulder) in thousandths. So i can check a gauge and see how a factory load compares to that or to a case that I have sized. I dont have a way to measure exact case head to datum. I dont think I need that. Also I never use a chamber cast to measure from base to anything since there is no base. I just use it to look at and mabie measure things in the throat shoulder area.

 

[fguffey]

I don't have a way to measure exact case head to datum.

If you understood 'the datum' you would be finished measuring your factory ammo from the shoulder/datum to the case head and you would know the length of the chamber from the shoulder/datum to the bolt face and you could verify your go-gage.

F. Guffey

 

[fguffey]

Hi Adam I believe that is true. In general I think their concern is that they will function for one shot and dont care what happens to the brass. Thanks

It is not in a reloaders vocabulary but factory ammo is minimum length/full length sized, and then there is go-gage length; after go-gage there is no go-gage length. Beyond that is field reject length. A reloader with a basic understanding of the datums can come up with 14 different length from minimum length to field reject length for the 30/06 chamber. It helps if the reloader has a good understand of the concept of zero.

F. Guffey

 

[Riesel]

Hi Riesel and carlsbad--You guys obviously are very knowledgeable in this area--Thanks for sticking with the thread. Here is what happened. I decided to rechamber the barrel and not mess with trying to ream the chamber deeper because I didnt want to mess up my reamer and I thought the chamber was crooked. It never shot well anyway so I removed the barrel from the action. I then decided to cerrosafe it to make sure of the crooked chamber and 3 grooves run all the way to the neck and the other three end about .080 from the neck. So I thought I would try rechambering it for sure and at least get a learning experience out of it. Today I thought Well I might as well try reaming the chamber by hand and see what I can learn doing that since I would be cutting it off some anyway. Oh and I lapped the lugs after I pulled the barrel. Anyway put barrel in vise, used alot of cutting oil and began reaming. I checked the depth of a go gauge in it first using a depth mic and checked and cleaned it often as I was reaming. I reamed it until I went what I thought was .002 deeper than cleaned it up and installed it back on action. Lo and behold when I stuck a no go gauge in the action and tried to close the bolt it did close with a little click at the bottom. So I overdid it a bit. I think lapping the lugs probably took a little and if I would have really wanted to save this chamber I would have went slower checking it on the action more. OF coarse the grooves still end where they did before- reaming didnt help that. Next up I only have enough room to mabie cut the threads off and rechamber, so I wonder if my new chamber will be any more concentric with bore--probably not but Ill find out and I know at least Ill get the headspace right. I will probably put a new barrel on it one of these days. Thanks for your help Hoz

Yeah, that barrel is probably a goner. Tent stake material, if it's crooked it will just stay that way, no matter how much lipstick you put on it.

 

[fguffey]

I went what I thought was .002 deeper than cleaned it up and installed it back on action. Lo and behold when I stuck a no go gauge in the action and tried to close the bolt it did close with a little click at the bottom. So I overdid it a bit.

Bolt click: That is good for another 4 pages of responses; and I wonder, how can that happen with all the help available on this forum. I suggested you learn to measure the length of the chamber from the shoulder to the bolt face. I would not start reaming a chamber until I knew the length of the chamber from the shoulder to the bolt face. And then there is reamer advance, as soon as the reloader learns to measure the length of the chamber he should start finding ways to control the amount or distance he plans on advancing the reamer.

Again, I size cases for short chambers, any reloader than can size cases for short chambers should be able to size cases for long chambers. (again) I have a chamber that has .016" added to the length of the chamber from the shoulder to the bolt face; problem? Not for me, I add .014" to the length of the case from the shoulder to the case head; that gives me the magic .002" clearance. And then there is the availability of cases, I neck up 280 Remington cases to 30/06 and then adjust the die off the shell holder .014".

And then there is the bolt click, I do not get the click sound, I have heard the 'snap' sound because that is what causes the sound.

F. Guffey

 

[fguffey]

I have a chamber that has .016" added to the length of the chamber from the shoulder to the bolt face;

Meaning the chamber is .002" longer than a field reject gage, the chamber is .016" longer than a minimum length full length sized case and .011" longer than a go-gage length chamber from the shoulder to the bolt face. And .009" longer than a no go-gage length chamber from the shoulder of the chamber to the bolt face.

F. Guffey