Rechambering to an Ackley

[Skunce]

I'm thinking about rechambering one of my 223 barrels to a 223AI. I've chambered many barrels for myself in the past, but have never done a rechamber to an Ackley. My concern is with a new barrel I would always have the reamer pilot fully engaged in the bore when reaming, but that won't be possible on a rechamber unless a good portion on the shank is cut off, which I prefer not to do. I understand that the usual procedure is to set the barrel back one turn first. Then cut the Ackley chamber because the chamber needs to be cleaned up completely and the brass needs a crush fit to form properly. I've been using a Bald Eagle reamer holder with good results in the past but, will the Ackley reamer follow the old chamber without the pilot in the bore?

 

[Dusty Stevens]

I would only rechamber one that similar by cutting the tenon off

 

[Skunce]

I would only rechamber one that similar by cutting the tenon off

I'll have to do some measuring and see if there is enough shank to do that. It's a Savage barrel that I don't have in hand at the moment and I'm just trying to get an idea on how it needs to be done.

Thanks Dusty

 

[Dusty Stevens]

Maybe on a savage cut half the threads off thatll buy you some length

 

[fguffey]

I'm thinking about rechambering one of my 223 barrels to a 223AI. I've chambered many barrels for myself in the past, but have never done a rechamber to an Ackley.

My concern is with a new barrel I would always have the reamer pilot fully engaged in the bore when reaming, but that won't be possible on a rechamber unless a good portion on the shank is cut off,

I have 65 reamers, I have access to an additional 250 reamers. Of the 315 reamers available not one of them has been shortened. There are receiver designs that do not allow a reamer to be placed into the chamber because there is no access from the rear. Then there are pull through reamers, I have access to pull through reamers; I do not have a pull through reamer. Then there are bolts that are modified that have been used when reaming a chamber.

You have reamed your chambers with success. Have you ever wondered why some ream their chambers to Ackely Improved without removing the barrel and or setting the barrel back? Then there is that part about; ‘what is the difference?

If the barrel is not set back when reaming a chamber to Ackely Improved the reamer will not clean up the chamber. The reamer will cut the chamber body and most of the shoulder but the reamer will not remove the case neck/shoulder juncture meaning part of the neck and shoulder will not be cleaned up.

Then there is the question; what difference does it make? The Ackley Improved neck is longer than the parent case neck. Put another way the case neck on the parent case is shorter; meaning when the parent case is chambered the case will not head space at the neck/shoulder juncture. When chambered the neck/shoulder juncture is formed when chambered and the rest of the case body and shoulder is formed when fired.

My concern is with a new barrel

If the barrel is new and has a short chamber make sure the chamber is short enough. My first suggestion is get drawings of the chamber in the barrel and drawings of the reamer.


F. Guffey

 

[Riesel]

I know this might sound a little far out there but I think it is worth looking at or trying.
With the barrel nut snug and the barrel properly headspace, back off the barrel nut and see how many additional threads you have. If you have four or five, you may be able to turn the breech face in a lathe to remove a couple of threads and give you room to work with that AI reamer. The reamer pilot should continue it's trip down the bore with no problem and give you the opportunity to cut that new shoulder and clean up that chamber. If you"boof" it, pick up the threads on the tenon and add you a few more to the barrel.
I would only attempt this if I was having a pretty good day and felt that I could tempt fate and get away with it.

 

[fguffey]

I know this might sound a little far out there but I think it is worth looking at or trying.
With the barrel nut snug and the barrel properly headspace, back off the barrel nut and see how many additional threads you have. If you have four or five, you may be able to turn the breech face in a lathe to remove a couple of threads and give you room to work with that AI reamer.

Excellent ideal; when he compares the drawings of the two cases he will find there is less than .010” difference in the length of the two necks. Meaning the case body/neck juncture will move forward and the neck/shoulder juncture will be moved ‘slightly’ back.


F. Guffey

 

[DuaneinND]

To answer your question, yes the AI reamer will follow the original chamber, so the real question is; how true is your original chamber and are the dimensions of your AI reamer sufficient to "clean up" the original chamber? The other question is; Do I feel lucky today. Fortunately since it is your rifle the only person you have to answer to is yourself, totally different than doing work for a paying customer. As a gunsmith if I screw it up I own it and I don't want it, so to error on the side of caution if you brought it into my shop, my answer would be the same as Dusty's, only if I can remove at least the tenon length.

 

[fguffey]

how true is your original chamber and are the dimensions of your AI reamer sufficient to "clean up" the original chamber?

my answer would be the same as Dusty's, only if I can remove at least the tenon length.

DuaneinND, Tell him how you would determine if the original chamber was true.

It is not easy to make something fool proof because not all fools read. I was minding my business when an owner of a rifle approached me at a gun show and wanted to know what happened to his rifle. He allowed a smith to chamber his rifle to 30/06. Problem; he had an Israeli 7.62 Mauser. The 30/06 reamer will not clean up the 308 chamber because the case body/shoulder juncture is about .014" larger in diameter than the 30/06 case body at the same distance from the case head. Out of curiosity I asked him who talked him into going from 308 to 30/06. I suggested he go to 30/06 Ackley Improved to get rid of the ring around the case. Then there were those that choose to ream the 7mm57 chamber to 280 Remington. When finished most will have two different neck diameters. Then there is always the chance the throat has erosion. Moving the chamber forward could be necessary for that reason.

F. Guffey