A buddy of mine had a guy rechamber two of his 243 rifles to a 243 Ackley. He took them out to fire form some brass and immediately knew something wasn’t right and brought them to me to fix them. I’ve chambered several rifles but never rechambered one so I have a couple questions. When getting the barrel straight in the lathe do I still use a range rod or put the reamer in the chamber and measure off the shank of the reamer? I am wanting to put blue layout dye in the chamber before I start so I can put my bore scope in there after I ream the chamber to make sure it is all a fresh cut. Will that work or will the filings remote the dye? Have read the barrel needs to be shortened only one thread to go from 243 to 243 Ackley. That really enough? I did castings of the chambers as they are now. Easy to see they aren’t right. I’m thinking the guy that did these the first time must have been using a standard 243 headspace gauge instead of an Ackley gauge. Thanks!
Rechambering
- Thread starter EasyShooter
- Start date
shortgrass
Silver $$ Contributor
Doesn't appear to have been set-back enough to completely clean-up the original chamber. You don't need an "Ackley" gauge. The "GO" gauge for the parent cartridge (in this case, .243 Win.) becomes the "NO-GO" for the Ackley chamber. The Ackley chamber is .004-006" shorter than the parent cartridge chamber. When P.O. Ackley developed these 'Improved' chambers , there was no such thing as "Ackley Improved" gauges, the "GO" for the parent chambering became the "NO-GO", and the depth mic was used. I allow the bolt to close partially with that "NO-GO" in the chamber, and then put a new piece of brass in and 'feel the crush' (between the bolt face and neck/shoulder junction), just to be certain. Best to use a piece of brass from the same lot as will be fire formed. It doesn't take a max charge to fully form, but I use more than the minimum charge.
DaveTooley
Gold $$ Contributor
The .004"-.006" shorter assumes the two have the same neck diameter. If the neck diameters are different then HS will vary from the norm. I have 40 degree gages for all my Ackley's for that reason.
Thanks for the responses. I had read that you could use the parent Go Gauge as a No Go. I have the 243 Go Gauge and tried it on both these rifles just to see where they were at before I tore them apart. Bolt closed easily on one and very tightly on the other. I have an 243 Ackley Go Gauge ordered so will see how it works on them once it comes in.
What is the preferred way to set the barrel up in the lathe? I would guess it would be best to follow the existing chamber instead of zeroing off the bore to make sure you don’t open the chamber up too big. Am thinking about putting the reamer in the chamber and zeroing off the reamer shank or just measuring directly off the existing chamber with the dial gauge.
Dusty Stevens
Shiner
If that casting is the same chamber just both sides avoid that guys method whatever you do
Those are castings of the chambers from first guy my buddy took his guns to. Two guns. Those are supposed to be 243 Ackley chambers. One doesn’t have the 40 degree shoulder deep enough, the other looks like it wasn’t cut at all. I measured the castings to make sure the chambers weren’t opened up too big already.
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Dusty Stevens
Shiner
Whats that step on the body of that one case?
You cannot just run an ackley reamer into a chamber and call it done. Whoever does that just stay away. The barrel must be set back a few turns and dialed in the lathe just like any chamber job
LVLAaron
Gold $$ Contributor
You know what it is. It's only a 50 percent improved.
Dusty Stevens
Shiner
I kinda like that combo neck there. I seen one like that one time that had a weatherby and an ultramag shoulder combo. Its hell waiting on dies tho
No way this is right! An AI should be be about .004 shorter at the the neck shoulder junction than it's parent case. IOW, about the average human hair difference. No way, no how is that new chamber cut right relative to the parent neck shoulder junction. You can barely see that amount, side by side, if then. Not gonna guess at what's up but I will definitively say that something was or is very wrong, somewhere. The Improved cartridge should be SHORTER than the parent, at the neck shoulder junction, period...if the intended wildcat is supposed to be an Ackley.
Not gonna get into it beyond that at the moment but the difference should be barely or not visible., at the critical nack/shoulder junction for any AI case/chamber. This doesn't meet that criteria.
That said, all AI's except the SAAMI 280 AI are wildcats, so whatever you intend...is correct, but it sounds like this was NOT the intended result, for whatever reason.
Not gonna get into it beyond that at the moment but the difference should be barely or not visible., at the critical nack/shoulder junction for any AI case/chamber. This doesn't meet that criteria.
That said, all AI's except the SAAMI 280 AI are wildcats, so whatever you intend...is correct, but it sounds like this was NOT the intended result, for whatever reason.
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Something is just very wrong. I didn't even look at it as long as you. Doesn't matter though. Someone either intended to make their own wildcat or they messed up. The other possibility is that they had no CLUE what they were doing\. Nevertheless, it should never have made it from the shop like that, even if it was done by the owner. Rule of thumb here is that headsapace gets checked at lest 3x times before it goes out, even on wildcats.
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AlNyhus
Silver $$ Contributor
Things like this just make me shake my head. Don't they test fire stuff for function? Jeezus......
Stan Ware had a sign in his shop aimed squarely at people like that: "A week ago I cudent schpel 'Guhnschmidt' and now I is one."
"Run, Forrest...run!!!!!!!"
Stan Ware had a sign in his shop aimed squarely at people like that: "A week ago I cudent schpel 'Guhnschmidt' and now I is one."
"Run, Forrest...run!!!!!!!"
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I just did a rechamber job yesterday. A 338 Lapua to 33XC. I dialed in this way.
First I cleaned the bore with Iosso. Direct reading off of fouling isn't a good method. Then I got the original chamber dialed in to zero runout. I indicated with my Interapid as close to the existing throat as I could and then at the back of the chamber. The reamer is going to follow that path anyway.
I then checked where the new throat was going to be. I went back and forth a few times until I had all three points as close to zero as possible. I normally put most of my effort on the throat area, but in a fired barrel--even one that has been cleaned--there is still a little fouling to mess up the readings. Realizing that I focused most on dialing the old chamber and getting the new throat very close. The reamer is going to follow the old chamber anyway.
The new chamber came out looking good. Hopefully it will shoot well. I really don't like rechamber jobs, but sometimes I have to do one.
I doubt he set back the threads, Rimless cartridges should always be set back, He obviously did not go in far enough with the reamer on either one of them.
You can use the go gauge of the parent case as a no-go, I chamber until the bolt closes about halfway on the go-gauge, Comes out perfect every time, A virgin case will have slight resistance when you close the bolt.
I wouldn't try that on a Re-chamber though, I would order the correct gauge.
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